The promotion of literacy encourages sharing knowledge by writing and reading. That provides the feelings of receiving and giving, a common ebb and flow of life.

Most commodity computers mute people by barricading their labeled buttonboards behind an unlabeled motionbox that must be repetitiously lifted, clunked, and slid with gymnastic precision. Options are what the software developers decided, are without immediate documentation (if any), and are hidden within a cavernous maze of non-personalized menus.

Personal expression and communication become possible with the ubiquitous skill of writing when the commodity software permits the buttonboard to function as a means for recording text. A "personalizable computer" is extensible beyond its default commands and options, as a person fits that within the current flow of events.

Freedom is a side-effect from taking on the responsibility of following through with personal interests. In other words, the experience of pursuing personal interests is the essence of living life, but is perceived externally or by self-reflection as freedom. The pursuit itself is active involvement, hence no absence of responsibility.

Opportunity is sometimes mistaken as freedom, as is the lack of molestation or expectation from other people. Like the fantasies of security and privacy, freedom is never taken away because it is only a perception. At most, freedom is disrupted like the daydream it is.

Blind trust of computer software written by strangers is avoidable, but it requires respecting personal interests and pursuits by saying "no" and being comfortable with the resulting freedom.

Jumping through hoops or over hurdles provides a false sense of accomplishment, a façade of freedom after the labyrinthine escape. Ideally, writing in the computer medium would be without an obstacle course entrance, as immediate as writing on paper.

Unique text editing software often produce unique file types, which make the documents eventually inaccessible when the software is abandoned by its company. Only plain text documents are accessible with any computer, old or new, commodity or personalized.

Plain text files are so versatile that all operating systems and programs are always made from them, although sometimes only the illegible compiled results are ever shared. Filesystems are the bridges between incompatible operating systems, a compatible means of transfering plain text files for reading and editing anywhere.

# notetaking with the computer medium

Paper is one of the best mediums for recording notes. Notes on a sheet of paper can be read by someone else without the need for that person to have a pad of paper.

Notes recorded in the computer medium are undeniably less accessible and less sharable. Computer documents require a computer for reading them, and the computer requires electricity.

A buttonboard with a button for each letter of the alphabet aids in writing legibly and quickly on a computer. However, the casual markings of underlining or thicker lines of text written on paper is typically beyond the limited set of symbols of a buttonboard.

Prose often has parentheses "( )" and square brackets "[ ]" distinguishing supplemental information, or quote marks specifying exact wording. Similarly, the uncommon angle brackets "< >" enclose a name for the kind of mark before its region of typed text.

# the motivation for markup

Whatever is typed is "plain text" when it is compatible with any operating system of any computer, from the past to the present and into the future. No need for converting a document that has plain text markup.

Spacing before and after paragraphs, thicker lines of text, and larger text for headings help demarcate and emphasize ideas. Some text editor programs merge that formatting with the prose in a way that is illegible and uneditable with any other text editor, thereby is no longer plain text.

Instead, consider two approaches: the primary view optimized for editing the text, and a temporary alternate view optimized for perusing. That is, when editing consider marking it when helpful for an alternate read-only view of the document.

Enclose the name of a mark within angle brackets "< >", whereby it is unmistakably distinguishable from the prose while ensuring compatibility as plain text. The alternate read-only view of a document is provided by a program hiding each mark while also modifying the appearance of the following text based on the name of the mark, without modifying the document itself.

Extra software for the alternate view is optional. Reading and editing personal or shared notes remains possible with any text editor on any computer, old or new, commodity or personalized.

# writing and marking plainly

The uncommon angle brackets < and > enclose a name for the kind of mark before its region of text. For example, thicker lines of text is known as "bold" text, therefore the mark is <b>. The region ends similarly with a forward slash "/" in the mark, f.e. </b>.

In other words, a region of text marked at its beginning with <b> would have </b> at its ending. Mnemonically, the "/" then "b" means "end b".

Normally drawn text with <b>this text to be drawn with thicker lines</b> and normally drawn text after it.

Sometimes the ending of a region is obvious by a mark beginning a new region after it, f.e. a paragraph after a paragraph, thereby the ending mark is conveniently optional.

<p>A paragraph of text that is followed by another paragraph.
<p>The previous paragraph obviously ends when this paragraph begins. This one has an ending mark, though it might be unnecessary.</p>

# using HTML for document sources

Hypertext markup language (HTML) is a system of named marks for typed regions of text. The marks evoke imagination of how the text would be drawn or spaced on paper, thereby promoting association and understanding of the content without an alternate view. The alternate view of an HTML document hides each mark and then applies its implied characteristics to its region of text.

For example, notes about some other document will often have the name of that other document for later reference. For computer documents, this more reliably also includes the filename of the document and its location.

The HTML mark for an address is <a> and is supplemented with the href attribute for the "hyperlink reference".

A hyperlink address region of text is underlined and becomes a trigger for viewing its specified document. That makes the alternate view more concise with document addresses, and enhances access to referenced documents.

# organizing and sharing files

A filesystem is a record of locations for documents (files) in a storage device. It tends to also be a source of the modification date and file size, but usually no special feature for comments or descriptions for files.

Commodity operating systems provide their own options for writing descriptions for a file, but those notes are inaccessible with other operating systems. The obvious compatible approach, regardless of operating system or type of filesystem, is consolidating personal descriptions of multiple files into a new document (file).

A document marked with HTML is plain text, therefore always accessible regardless of what computer. Type or copy/paste the document name and optionally mark it as a hyperlink address, perhaps followed by a description. Maybe mark each as a paragraph <p>, or grouped into distinct lists preceded by headings.

In this way, the reason for having each document or image is available, rather than opening each and every document with many different applications and trying to remember later. Documents without descriptions, reasons, or relations to other documents become prime candidates for removal in order to reduce clutter.

Include a framed view of either an HTML document or an image by referencing its source address in the src attribute of an internal frame <iframe>. The view of the document or image is scrollable when larger than the internal frame, which also can have width and height attributes (pixel values).

<iframe src="some-other-document.html"></iframe>
<iframe src="can-be-an-image.jpg" width="400" height="300">
This region is shown instead of the document only when a HTML viewer has no support for the iframe mark.

Or, add an image with the <img> mark and optionally scale it with width or height attributes (pixel values). There is no end mark for it.

<img src="an-image.jpg">
<img src="another.jpg" width="500" height="375">

Perhaps establish a tiled layout (split view) for previewing a set of documents with each at 50% width [need style attribute for non-pixel values], t.i. one pair at a time. Note that 50% + the width of one space character + 50% = more than 100%, so ensure there is no space between the end of one mark and beginning of the next.

src="doc-1.html" style="width:50%;height:30em;border-width:0">
src="doc-1_backup.html" style="width:50%;height:30em;border-width:0">
src="doc-2.html" style="width:50%;height:30em;border-width:0">
src="doc-3.html" style="width:50%;height:30em;border-width:0">

No matter what operating system, even from before the turn of the century, every computer comes with a simple text editor for editing plain text and an HTML viewer (a.k.a. web browser). Thereby, the document can be viewed in any web browser on any computer, and without need for a webserver or even an internet connection.

No special programs necessary, no extra cost, and HTML is as plain as the buttons on a buttonboard.

# essential HTML

The "language" in HyperText Markup Language (HTML) means it is a system or set of keywords. There is no communication by the means of HTML.

HTML marks are guidance for a temporary read-only view of a document. Sort of like proofreader marks, with a name consistently encapsulated within < and >. Sometimes after the name there is more describing the characteristics of the mark itself, before the >.

The angle brackets "< >" make the occasional HTML mark unmistakably distinguished from the prose, just like parentheses or square brackets. They are often readily available on the comma and period buttons of the buttonboard.

Any text can be placed in between < and >. Just type whatever. Programs providing a read-only view of a document with HTML marks generally ignore any unknown named marks and never show them.

The ".html" at the end of the filename for a document is typically the only (artificial) requirement made by the operating system and its applications. All HTML marks are optional, as such a document declared to be HTML can be just prose without any marks.

Links are "hyper" because the text is marked with an address for a location within the document or to another document. In other words, a link is an option to view some other part of the document or to view another document. A hyperlink is traditionally underlined by HTML viewers.

Mark a location in a document with an address mark and the id attribute. No need for anything within its region, merely type the marks before something interesting, like before a heading.

Mark text as hypertext with a reference href in an address mark <a href=""> before the text, then follow the text with the </a> ending mark.

In essence, making a note about another document typically involves typing the title of the document, and typing the address of where to find it. In other words, that is the act of referencing a source. A hypertext link is the same thing, with just a few more characters to type. The same information is recorded, and it will be a link in the read-only HTML view.

Include a framed view of either an HTML document or an image by referencing its address in an internal frame <iframe>. The view of the document or image is scrollable when larger than the internal frame, which also can have width and height attributes.

<iframe src="some-other-document.html"></iframe>

<iframe src="can-be-an-image.jpg" width="400" height="300"> This region is shown instead of the document only when a HTML viewer has no support for an iframe. </iframe>

Specifically add an image with the <img> mark and reference its source with the src attribute. There is no end mark for it. Optionally scale the image with its width or height attributes.

<img src="an-image.jpg">

<img src="another.jpg" width="500" height="375">

The same document or image can be referenced multiple times. That can be convenient for comparing side by side [perhaps each at 50% of the view width] one original version with many other versions, pairing a reference to the original version with each of the other versions.

Change the default characteristics of any mark with the style attribute for it. A colon associates a characteristic with its value, and a semicolon separates characteristics. Optionally use spaces around the colon or semicolon for clarity.

For example, set the width of a paragraph and center it horizontally.

background-color: black
;color: beige
;text-align: right
;width: 50%
;padding-top: 1em
;padding-right: .5em
;border-top-color: fuchsia
;border-top-style: dashed
;border-top-width: 10px
;border-right-style: solid
;border-right-width: .25in
;border-bottom-color: teal
;border-bottom-style: double
;border-bottom-width: 3mm
;/* Using automatic margins
centers the region. */
margin-top: 2em
;margin-left: auto
;margin-right: auto
">For example, set the width of a paragraph and center it horizontally.

# dual-system personalizable computer, an approach

Be wary about putting all the eggs in the same basket. Discrete purposes with their own resources stay separate, thereby one is affected by its own needs or demise without draining other resources or damaging anything else.

In other words, rather than a large amount in one container, consider smaller amounts in multiple containers. Dedicating resources sparingly minimizes corruption or loss, while freeing remaining resources for additional or simultaneous endeavors.

An operating system needs its own memory storage, separate from other operating systems, because "operating" means automated programs are doing whatever without being monitored. They can readily corrupt anything on the remainder of the storage device.

For example, there has been one operating system (late second decade of 21st century) that replaces the partitions and filesystems of the whole storage device with its new and improved version of partitions and filesystems. Unfortunately, the prior version of that same operating system is unable to recognize the storage device anymore, which means it is impossible for it to use the memory device. Reliability comes from discrete use, rather than shared.

Personalizable inherently means modular. The operating system is always kept on external storage, never permanently inside a personalizable computer. In that way, the computer can be started by attaching any operating system compatible with its hardware. Keep a backup on a second external storage device, then that can be use to start the computer when the primary fails.

Personal documents are always kept separate from the operating system, ideally on a separate storage device. In that way, they can be attached to any computer, rather than trapped inside a computer that fails to start. For example, personal documents on separate storage are easily taken to a computer located beyond a local electrical power outage, or simply attached to a nearby computer that uses a battery.

One computer with two memory storage devices for an operating (or operatable) system, primary and backup. Two more storage devices for personal documents, primary and backup. Perhaps another set of storage devices for additional software. The amount of memory per storage device can be minimized for each purpose, no need for terabtyes in one device. Operating systems tend to use only a few gigabytes, but some operating systems are only a few megabytes, f.e. TinyCore and piCore.

Never update nor upgrade an operating system, nor any software application. Instead, install the next version on a separate storage device, and try it out discretely without losing the currently working version. Creating a new instance fits with the core principle of computing: make and work on a copy.

Again, the memory devices need only as much memory as required for that particular purpose, no need for terabytes. Separate memory devices for trial of updates or upgrades can be reused for that specific purpose, discretely from personal documents and discretely from stable software.

Reliably customizing a computer requires using some other computer that is stable and remains stable. That is, a primary computer is used to setup a secondary computer. Once the secondary computer has its new modifications stabilized, then the secondary computer is eligible as a replacement for the primary computer.

Adding another computer requires only enough memory storage for its operating system (compatible with its hardware), but eventually two such memory devices: primary and backup. Once again, very small amounts of discrete memory rather than large amounts, t.i. gigabytes (or just megabytes) instead of terabytes, allows for sensible and affordable personalization of computers.

A physical computer tends to have small amounts of special memory (firmware) for itself on its circuitboard, memory that can be changed by operating system updates or upgrades, potentially removing features or causing corruption. That is why it is important to have a second computer (hardware) for customizing, isolating the aforementioned possible corruption of its circuitboard memory (firmware) by operating systems or their updates.

By using a primary system to customize a secondary system, whatever happens to the secondary system (software or physical) can be assessed from the primary system. Furthermore, some tasks can be offloaded to the secondary computer (when it is stable enough) rather than stressing or slowing the priorities of the primary computer.

# pet rocks: wasteful manufacturing

[ This is eventually for a section of notes about the wastefulness of products, and the characteristics of a worthwhile product. ]

Some factors:

[ A collection of formerly useful products is comparable to a collection of interesting looking rocks, also known as pet rocks. Such a collection of novel contraptions might be worthy for a museum, but is more of a reflection of prior personal interests (perhaps no longer accurately representing). ]

# Resources

# Markup a CSS stylesheet

A stylesheet for stylesheet documentation, a.k.a. a hybrid CSS+HTML document.

The "style" of Cascading Style Sheet refers to expression rather than decoration, because CSS is for changing the default spacing and drawing of HTML marked regions of plain text documents. Therefore, CSS actually describes the characteristics of HTML marks rather than the document.

The intent of a CSS stylesheet is documented with comments embraced by /* and */. Comments can be marked up with HTML, whereby documentation for a stylesheet can have an alternate view in an HTML viewer.

A well-documented stylesheet inevitably links to itself for providing samples of its rules within its documentation. Therefore, a "stylesheet stylesheet" such as this one is "the mother of all stylesheets", as it precedes and begets all thereafter.

# PDF: portable document format

Portable Document Format (PDF) describes how to layout text and images, and is plain text. Basic notes for PDF version 1.4, mostly with the purpose of combining images into a single PDF document.

# ed and emacs, an approach

For many decades, emacs (Editing MACroS) has provided split-view management of documents (viewing and editing). It also excels with memory management of any sequence of typing or list of commands by storage in "registers", or complete repetition by a single press of any button desired (a.k.a. keyboard macros). The Emacs command "append-to-buffer" provides a means for selectively transferring content from any view of Emacs (whether a document or otherwise) to any other view, bypassing its own copy/paste or "registers".

On the other hand, the text editor "ed" reveals any fragments of any number of documents when requested, in any order, gradually filling the screen only as needed. Each line is called forth by its number, so the line number is an intuitive command that shows that line of text. With "ed", there is no need for moving a text cursor, no need for selecting text, and no need for scrolling.

Any comma-separated range of lines is a command for calling forth that range of lines, f.e. 31,35p will "print" lines 31 to 35 on the screen. Line numbers are optionally revealed when requesting lines (f.e. 31,35n), and similarly so in search results. Specify a generic line number with plus or minus, f.e. -4 for the fourth line before the current line, or for a range of lines, f.e. -5,+5p to "print" the range of lines of text before and after the current line. The last line requested automatically becomes the current line.

Thereby with "ed", views of text emerge naturally from requested fragments of familiar documents: command, lines of text, command, lines of text, etc. That is, the typed command remains visible and serves as an introduction for the lines listed by it (when any).

A document can be viewed one screenful at a time (with z), or by an arbitrary number of lines (f.e. z30 for the next 30 lines), from anywhere within a document (f.e. 42z30n for the 30 lines starting from line 42, and numbered).

Search results are listable, or traversable one at time by line number in any order desired, and repeatable without retyping the search pattern. In addition to mere search and replace, a set of commands can be applied to all search results or interactively queried for each one. For example, search for a pattern, but also specifiy a different pattern for replacing in the results, all as one command, and either immediately or selectively.

As aforementioned, the editing commands typed in "ed" remain visible, thereby keeping a history of how a document was edited (optionally with the lines of text before and after they were modified) would be possible... if only there was a means for saving those proceedings.

By using "ed" for its naturally emerging document views within the "shell-mode" of Emacs, the "ed" program gains a separate dedicated buffer from Emacs recording that history of all editing with "ed", along with robust command editing (from the text editing commands of Emacs) when typing its own commands. Of course, the aforementioned keyboard macros from Emacs means commands within "ed" are automatically added to any recorded sequence of tasks, and naturally so. No special effort needed, nothing new to learn, automatically incorporated.

Evoking "ed" within shell-mode with sudo (super-user do) means the ability to edit restricted system documents without having to do "sudo emacs", thereby the super-user role remains optional within Emacs.

With the "!" command provided by "ed", evocation of external commands are possible from within "ed", and their results optionally inserted into that document wherever desired. Evoking "ed" as super-user (t.i. "sudo ed") also means there is no longer any need to type sudo for each and every command that requires super-user privileges, because the "!" command of "ed" will evoke external commands with the same privileges by which "ed" itself was evoked.

The split-view management of Emacs provides the opportunity for multiple full-screen layouts of several such instances of "ed" and "sudo ed" in shell-mode, intermixed with any other activities within Emacs, f.e. email, web browsing, directory listings, etc. As each instance has its own dedicated buffer, the editing history of commands used in "ed" or "sudo ed" can be saved for review or potential selective restoration of edited documents (for when lines were listed before and after editing them). And of course, repetition of super-user tasks, editing or otherwise, becomes possible (and naturally so) by means of the aforementioned keyboard macros of Emacs.

Using "sudo ed" within shell-mode of Emacs enables responsible, recordable (t.i. record keeping), and administrative editing of documents or evocation of commands with access to copious amounts of copy/paste access (a.k.a. "registers"), and ridiculously easy on-the-fly record/play of any sequence of typing and commands... readily assigned to any button desired, as many as needed.

# Lisp lists are pairs

As a single item has no associates, a list of items conceptually begins when an item is paired with another. Written horizontally, one item is the left half and one item is the right half.

Multiple pairs of pairs exponentially increase the potential storage of items: 2, 2*2, 2*2*2, 2*2*2*2 and so forth. Therein, an item is efficiently accessed by halving. Positionally reference one half the list, either left or right, for each pairing: once for any item of 2, twice for any item of 2*2, thrice for any item of 2*2*2, and so forth.

Consistently pairing a new item right of a list forms a stream of half-pairs rightwardly, or when left of a list forms a stream of half-pairs leftwardly.

# Dotted-pair notation

For Lisp, a list is constructed parenthetically one pair at a time, and notated with a space-separated-dot, t.i. a period with spacing before and after. The spacing is important because numbers can have decimal points, and Common Lisp allows a period as a character in the name of a symbol (CLHS examples).

   ("A message for later." . a-lisp-symbol)

   (one.symbol . 3.141592)

However, a parenthesis has no actual need for spacing on either side of it, neither "(" nor ")".

   ((((1 . 2). 3). 4). 5)

   (5 .(4 .(3 .(2 . 1))))

# Dexter and abdexter

The cons function constructs a new list by pairing the two Lisp forms it is given, perhaps quoted (An intro for Lisp).

   (cons (quote left) 'right)
     ->  (left . right)

In essence, a list is itself a single item. Therefore, lists are constructed further by pairing the next item with a prior list. As a left or right half, an item is readily referenced by its position within a sub-list, t.i. from inside to outside.

   (left . right)

   (L . R)

   ((LL . RL) . R)

   (L . (LR . RR))

   ((LL . RL) . (LR . RR))

For example, "the left half of the right half" references the left item of a sub-list, and that sub-list is the right half of another list. That describes the position (which side of the dot) from the inside list to the outside list, and is succintly described as the "LR". However, multiple "l" and "r" sounds smoothly slur together ambiguously when spoken.

Another term for the right side is the dexter, or adjectively as "dextral" for the dextral half, and traditionally left is "sinister" (fitting with Scheme dialect?) when paired with dexter. However, "s" and "d" are both pronounced at the front of the mouth.

Alternatively, abdexter also applies as an alternate to dexter. The "ab" prefix means "away", f.e. abduct contrasted with adduct. The glottal vowel "a" of abdexter (left) is of the throat and clearly contrasts with the dental consonant "d" of dexter (right) at the front of the mouth.

Therefore, "abdexter" and "dexter" provide sequences of sub-lists succinctly written and clearly spoken with either one letter or one syllable per sub-list. The vowel "a" is distinct from the consonant "d" despite variation of vowels in regional dialects of English. The written letters contrast with each other, with numbers, and with symbols on the buttonboard, either when lowercase "ad" or when uppercase "AD" or when mixed "cADr".

   (abdexter . dexter)

   (a . d)

   ((aa . da) d)

   (a . (ad . dd))

   ((aa . da) . (ad . dd))

From inside to outside, "the left half of the right half" is the same as "the abdexter of the dexter", or the "ad" which is pronounced individually as "a-d". Visually, it is the item left of its dot within the sub-list right of its own dot.

As a sequence from inside to outside, it is readily understood from outside to inside by reading it reversely. Therefore, the prior example of "ad" also refers to the dexter of the outer list (right half) and then the abdexter (left half) of the sub-list. Dexter remains dexter, and abdexter remains abdexter, so it is the same follow-the-dot approach either way.

# Reference a half: cdr and car

For the pair of items in a list, call for its dexter reference with the cdr function, and call for its abdexter reference with the car function (An intro for Lisp).

   (cdr '(a . d))
     ->  D

   (car '(a . d))
     ->  A

Chaining multiple references accesses a list initially from its outside then gradually towards its inside, thereby producing the inside-out sequence naturally.

       (car (car '((aa . da) . d)))
   ==  (car '(aa . da))
         ->  AA

       (cdr (car '((aa . da) . d)))
   ==  (cdr '(aa . da))
         ->  DA

Multiple car and cdr references can be abbreviated with the concise sequences, too, though Common Lisp provides functions for only up to four places, f.e. cddddr. It is a bit like simply removing the "r(c" of consecutive functions, and their corresponding ")".

       (car(cdr '((aa . da) . (ad . dd))))
   ==  (cadr '((aa . da) . (ad . dd)))

# Re-listing rather than re-arranging

Realize the difference between a list of items and the items themselves, for it is the same difference between a grocery list and the groceries themselves. Similarly, the cdr and car references are the positions in a list rather than the items.

The cons constructs a new list. The setf (An intro for Lisp) replaces a reference at a position in a list with another rather than modifying the content. List items are never moved, neither within a list nor from one list to another.

The Lisp interpreter uses the items, and also conveniently prints a copy of the actual items rather than the memory locations. However, that obscures whether a placeholder name has the original or only a reference.

Consider preventing ambiguity by naming a placeholder with intent when using setf.

   (setf list.1 '(one two three four))
     ->  (one two three four)
   (setf part.1 (cdr list.1))
     ->  (two three four)
   (setf part.1.ref (cdr list.1))
     ->  (two three four)

   (cadr list.1)
     ->  two
   (setf (cadr list.1) 'five)
     ->  five

   (cadr part.1)
     ->  three
   (setf (cadr part.1) 'six)
     ->  six

   (caddr part.1.ref)
     ->  four
   (setf (caddr part.1.ref) 'seven)
     ->  seven

     ->  (one five six seven)
     ->  (five six seven)
     ->  (five six seven)

 ;; Consing references.
   (setf list.2 (cons list.1 part.1.ref))
     ->  ((one five six seven) five six seven)

 ;; Setting placeholder.
   (setf part.1.ref 'eight)
     ->  eight

 ;; Changing reference.
   (setf (cdr part.1) 'nine)
     ->  nine

     ->  (one five . nine)
     ->  (five . nine)
     ->  eight

 ;; No surprise, maybe.
     ->  ((one five . nine) five . nine)

[ ...

Consider copy-list (CLHS) to copy the structure of a list without copying the content. Consider copy-tree (CLHS) for a list of pairs of pairs. Consider copy-seq (CLHS).

... ]

# Consistently half-paired lists

Besides the purposful construction of a list, there are a couple of obvious approaches for consistently constructing a list of arbitrary content.

   ((((1 . 2). 3). 4). 5)

   (5 .(4 .(3 .(2 . 1))))

Consistently pairing a new item right of a list forms a stream of half-pairs dextrally, ensuring the final item added is readily accessible with merely the cdr function.

      (1 . 2)
      (a . d)

     ((1  . 2)  . 3)
     ((aa . da) . d)

    (((1   . 2)   . 3)  . 4)
    (((aaa . daa) . da) . d)

   ((((1    . 2)    . 3)   . 4)  . 5)
   ((((aaaa . daaa) . daa) . da) . d)

Consistently pairing a new item left of a list forms a stream of half-pairs abdextrally, meaning the final item added is readily accessible with the car function instead.

                        (2 . 1)
                        (a . d)

                  (3 . (2  . 1 ))
                  (a . (ad . dd))

           (4 . (3  . (2   . 1  )))
           (a . (ad . (add . ddd)))

   (5 . (4  . (3   . (2    . 1   ))))
   (a . (ad . (add . (addd . dddd))))

A half-paired list of n items bypasses most its potential of 2^(n-1) items. For example, a 10 item half-paired list has 9 pairings wherewith it has 2^9 or 512 total possible positions. However, its other 502 locations are open for potential expansion.

Perhaps meaningfully pair each current item with an additional shorter half-paired stream or a chunk of pairs of pairs. Similarly for the 256 potential positions in the other half, perhaps as complementary information.

# Abbreviated notation for a dextral list

A space separated dot before a parenthetical list, t.i. the dextral half, can be abbreviated by removing both that prior dot and the parentheses for that next list. Notably, the Lisp interpreter favors this abbreviation for a dextral list, such as in abdextrally constructed lists, when printing Lisp forms in messages.

       (a .(ad .(add .(addd . dddd))))
   ==    (a ad .(add .(addd . dddd)))
   ==      (a ad add .(addd . dddd))
   ==        (a ad add addd . dddd)

       (a .(ad .(add .(addd . dddd))))
   ==    (a .(ad .(add addd . dddd)))
   ==      (a .(ad add addd . dddd))
   ==        (a ad add addd . dddd)

One way of reversing that abbreviated notation is by pairing items from left to right, t.i. explicit dotted-pair notation of the car with the cdr.

       (a ad add addd . dddd)
   ==  (a .(ad add addd . dddd))
   ==  (a .(ad .(add addd . dddd)))
   ==  (a .(ad .(add .(addd . dddd))))

In other words, two items in a list without a dot between them means everything on the right half is actually another list. A Lisp list is truly a pair.

A list printed by the Lisp interpreter that appears to have only one item is actually paired with a dextral list, though it is empty. An empty list is also known as nil (Lisp and NIL).

   ==  (a .())
   ==  (a . nil)

       (a ad)
   ==  (a .(ad))
   ==  (a .(ad .()))
   ==  (a .(ad . nil))

# Contrary pairing and Lisp instructions

A Lisp function is essentially used in an abdextrally half-paired list with the function name conveniently in its abdexter. This also fits well with typing text from left-to-right, but that is contrary to the natural leftward formation of abdextrally half-paired lists.

Contrary formation either dextrally or abdextrally is simple with setf (An intro for Lisp) by pairing the new content with the content of the innermost contrary position.

   (setf dex-list '((2 . 3). 4))
     ->  ((2 . 3). 4)

   (setf (caar dex-list)
    (cons 1 (caar dex-list)))
     ->  (1 . 2)

     ->  (((1 . 2). 3). 4)

A list as a Lisp instruction, such as for a Lisp function, is an abdextrally half-paired list that started with nil as its dextral half. Therefore, substitute the innermost contrary position with a pairing of the desired content and nil for maintaining that integrity.

   (setf do-it-later
    (quote (setf one 1)))
     ->  (SETF ONE 1)
     ==  (SETF ONE 1 . nil)

   (setf (cdddr do-it-later)
    (cons 'two nil))
     -> (TWO)

     ->  (SETF ONE 1 TWO)
     ==  (SETF ONE 1 TWO . nil)

   (setf (cddddr do-it-later)
    (cons 2 nil))
     -> (2)

     ->  (SETF ONE 1 TWO 2)
     ==  (SETF ONE 1 TWO 2 . nil)

   (setf (cdr (cddddr do-it-later))
     (cons 'three (cons 3 nil)))
      -> (three 3)

     ->  (SETF ONE 1 TWO 2 THREE 3)
     ==  (SETF ONE 1 TWO 2 THREE 3 . nil)

Unwinding an abdextrally half-paired list (Exploring a half-paired list) exposes the innermost contrary position.

   (setf later (quote (setf one 1)))
     ->  (SETF ONE 1)

   (setf later (cons nil later))
     ->  (NIL SETF ONE 1)

   (setf later
     (cons (cadr later) (car later))
     (cddr later)))
     ->  ((SETF) ONE 1)

     Twice more...
     ->  ((1 ONE SETF))

   (setf (car later)
    (cons 'two (car later)))
     ->  (TWO 1 ONE SETF)
     -> ((TWO 1 ONE SETF))

   (setf (cdr later)
    '(2 three 3 . nil))
     ->  (2 THREE 3)
     ->  ((TWO 1 ONE SETF) 2 THREE 3)

   (setf later
     (cdar later)
     (cons (caar later) (cdr later))))
     ->  ((1 ONE SETF) TWO 2 THREE 3)

     Thrice more...
     ->  (NIL SETF ONE 1 TWO 2 THREE 3)

   (setf later (cdr later))
     ->  (SETF ONE 1 TWO 2 THREE 3)

# List introspection in Lisp

A Lisp list is constructed as a pair with cons, and the car and cdr reference its left and right halves (Lisp lists are pairs). This provides an opportunity for pairs of pairs, as well as sequentially formed (t.i. half-paired) lists either abdextrally or dextrally.

Abbreviated functions consolidate two, three, or four car and cdr references, f.e. cadddr or cddddr. Access any of 2^4 or 16 halves with a single function, or any of 2^(4+4) or 256 items with two functions, or any of 2^(4+4+4) or 4096 with three functions, and so forth.

# Pairs of pairs accessed sequentially

A pair is 2 items, a pair of pairs is 4 items, a pair of pair of pairs is 8 items, and so forth exponentially. An item in an exponentially paired list is referenced by gradually halving the list towards its position and noting each half leading to it.

The sequence of bisecting directions from outside to inside is also a binary description, thereby a binary number for each item. Assigning "left" as 0 and "right" as 1 reveals the sequence of binary digits for each item, but with the binary digits reversed.

  Paired once:   2^1 = 2 items
     car cdr
     (a . d)
      0   1

  Paired twice:  2^2 = 4 items
     caar cdar   cadr cddr
    ((aa . da) . (ad . dd))
      00   10     01   11
      0    1      2    3

  Paired thrice: 2^3 = 8 items
     caaar cdaar   cadar cddar     caadr cdadr   caddr cdddr
   (((aaa . daa) . (ada . dda)) . ((aad . dad) . (add . ddd)))
      000   100     010   110       001   101     011   111
      0     1       2     3         4     5       6     7

The numbers sequentially increase from left to right starting from zero, the equivalent of the rightward displacement of each item from the left end. The first item from the left has 0 items before it so skip zero items, the second item from the left has 1 item before it so skip one item, and so forth.

Therefore, the consecutive references with car and cdr describing the traversal from inside to outside for an item is equivalently the reversed binary digits for the rightward displacement of an item.

Access an item by noting its perceived sequential displacement as a reversed binary number. It has the same number of digits as the number of times an item is paired within the list, or the number of parentheses at the beginning or ending of the list.

For example, each item in a list of 16 items is paired four times (2 * 2 * 2 * 2 = 16), so consider the binary number for a position as four digits. The sixth item is displace by 5 others, 5 is #b0101, reversed is 1010: use cdadar.

Recall, only one function is needed for referencing any of 16 halves, two functions for any of 2^(4+4) or 256, three for any of 2^(4+4+4) or 4096, and so forth. For example, the cdaar of the cdadar is the 42nd item of 128 (t.i. 2^7), but so is the cdaadr of cadar, because it is the "daadada". (But, within 64 items the 42nd is only "daadad".)

Consider using the Lisp interpreter for revealing binary numbers. The format (CLHS) prints a number as binary with ~b (CLHS Or, also give the number of desired digits and a zero (preceded by an apostrophe ') (CLHS for padding empty places. Then use the reverse (CLHS).

   (format nil "~b" 41)
     ->  "101001"
   (format nil "~7b" 41)
     ->  " 101001"
   (format nil "~7,'0b" 41)
     ->  "0101001"

   (reverse (format nil "~7,'0b" 41))
     ->  "1001010"

# Exploring a half-paired list

A half-paired list is a singular item paired with another list, implying its first pairing is with an empty list, t.i. nil. Access the singular item of an abdextrally half-paired list with car, or of a dextrally half-paired list with cdr.

A consistently half-paired list is continuously deconstructable by referencing its inner list, with cdr for an abdextrally half-paired list or car for an dextrally half-paired list. Setting aside the singular items by constructing a new half-paired list opportunes reconstruction of the original list.

    dexi nil
    abbi '(1 .(2 .(3 .(4 . nil)))))

   Dextrally cons             De-cons the
   a half-paired list.        abdextrally half-paired list.

   (cons dexi (car abbi))     (cdr abbi)

                (nil . 1)     (2 .(3 .(4 . nil)))
                       |       |
                      cdr     car

The foremost item of the inspected half-pair list is set aside as the former middle item. The inspected half-pair list is then deconstructed to its inner list, thereby exposing the next middle item.

Gradual unwinding exposes the middle items of the inspected list consistently with cdr or car from either replacement list. Pairing both lists into a new list would maintain that point of introspection. The order of the pairing is only a matter of preference because both halves are equally accessible.

Consider constructing dextrally half-paired lists from items of an abdextrally half-paired list, while constructing abdextral replacements. Pairing the two new lists with the dextrally half-paired list as the abdexter maintains the visual appearance of the sequence order when printed.

   (setf coil
     (cons nil '(1 .(2 .(3 .(4 . nil))))))

   ->  (nil 1 2 3 4)

     (setf coil
       (cons (cAr coil) (cADr coil))
       (cDDr coil)))

                         Middle items:
                         cDAr     cADr
                            |     |
                        (nil   . (1 .(2 .(3 .(4 . nil)))))
                    ((nil . 1) . (2 .(3 .(4 . nil))))
               (((nil . 1). 2) . (3 .(4 . nil)))
          ((((nil . 1). 2). 3) . (4 . nil))
     (((((nil . 1). 2). 3). 4) .   nil)

       (setf coil
         (cAAr coil)
         (cons (cDAr coil) (cDr coil))))

   Abbreviated:                   Default Lisp printer:

       (nil   1   2   3   4)      (nil 1 2 3 4)
      ((nil . 1)  2   3   4)      ((nil . 1) 2 3 4)
     (((nil . 1). 2)  3   4)      (((nil . 1) . 2) 3 4)
    ((((nil . 1). 2). 3)  4)      ((((nil . 1) . 2) . 3) 4)
   (((((nil . 1). 2). 3). 4))     (((((nil . 1) . 2) . 3) . 4))

A pair of abdextrally half-paired lists is most compact from the Lisp printer, because it favors the abbreviation for when a list is the dextral half of a pair (Abbreviated notation for a dextral list).

   (cons nil '(1 2 3 4 . nil))

   ->  (nil 1 2 3 4)

   Introspection:                           Default Lisp Printer:
    caar              cadr
     |                 |
      (nil          . (1 2 3 4 . nil))      (nil 1 2 3 4)
   ((1 . nil)       . (2 3 4 . nil))        ((1) 2 3 4)
   ((2 1 . nil)     . (3 4 . nil))          ((2 1) 3 4)
   ((3 2 1 . nil)   . (4 . nil))            ((3 2 1) 4)
   ((4 3 2 1 . nil) .   nil)                ((4 3 2 1))

[ ...describe using introspection for gradually constructing a Lisp form (which is an abdextrally half-paired list). Also consider revising the examples in StumpWM section, promoting defining buttons for introspecting forwards and backwards, which now makes it easier to append to the innermost contrary position of a half-paired list with just car (after unwinding the list all the way to nil)... ]

[ ...

Consider associating each instruction to a button on the buttonboard (Custom commands), one for the next list item and one for the prior list item. Associate the placeholder name to another list for modifying it (Re-listing) with introspection, and prepend it with nil. Afterwards, rewind it completely and remove the prepended nil, then set the placeholder name to nil to detach the association.

Consider copy-list or copy-tree.

... ]

[ ...describe including the nifty (+ 1(length(car for position of introspected item for each evaluation by means of each defined key. For example, consider the cons for pairing the introspected item (as dexter) with its position for stumpwm:eval-line, like when introspecting keysyms for keycodes listing (but that would be without the plus one because the keycodes were matched with the default zero indexing of arrays)... ]

# Lisp and NIL: No Items in List

Embracing items with parentheses
 acknowledges those items
 are associated with each other.

Nil is an empty list,
 as in "nothing in list".
 But that also asserts "Nil Is a List"
 rather than nothingness itself.
 It has become the mnemonic name
 for an empty set of parentheses.

   nil  ==  ()
        ==  '()  ; quoted Lisp form

A list of one item
 is never notated as a list,
 t.i. it has no parentheses.
 It is written simply as the item itself,
 for there are no other items associated.

A list of more than one item
 is notated as a dotted list,
 with a spaced separated period
 before its final item.

   '(one two . three)

A list with nil as its final item
 is commonly abbreviated
 without dotting with nil.

   '(one . nil)  ==  '(one)

A list of items without
 a dotted final item
 has visually consistent
 delimitation, thereby
 is a "proper list".
But as a list without
 a dotted final item,
 a proper list is merely
 the abbreviated form
 for its items dotted with nil
 as the final item.

   '(one)  ==  '(one . nil)

As such, a proper list with only nil
 is a list with an empty list:

   '(nil)  ==  '(())

 but is also the abbreviated form
 for a list of items dotted with nil
 as its final item:

   '(nil)  ==  '(nil . nil)

 which is a dotted list of two lists,
 or the egregious enlightenment emoticon
 for "I am become nil":

   '(nil)  ==  '(() . ())


Consing constructs a dotted list.

   (cons 'one 'two)
     ->  '(one . two)

Multiple consing results in
 the last item added
 becoming the first.

   (cons 'three       ; second cons
    (cons 'one 'two)) ; first cons
      ->  '(three one . two)

Consing an item with nil
 results in a proper list,
 because a proper list
 is the abbreviated form
 for its items dotted with nil
 as its final item.

   (cons 'three            ; third cons
    (cons 'two             ; second cons
     (cons 'one nil)))     ; first cons
       ->  '(three two one . nil)
       ==  '(three two one . ())
       ==  '(three two one)

A proper list beginning with nil
 begins and ends with a list.

   (cons nil '(one))
     ->  '(nil one)
     ==  '(nil one . nil)
     ==  '(()  one .  ())

# StumpWM: an instantaneously extensible computer interface

The split-view manager StumpWM is a lisp image exported from SBCL (Steel Bank Common Lisp), and is intended for managing the Xwindows of an Xserver.

Split-views are adjacent non-intersecting areas, like tiles, thereby efficiently encompassing the whole screen. Initially, StumpWM was known as "ratpoison" because it focused on eliminating any requirement for an electronic device emulating the toggling of the buttocks on a rodent.

As an SBCL Lisp image, StumpWM is actually a copy of the SBCL lisp interpreter with the code for StumpWM built-in. That means starting StumpWM is the same as starting a lisp interpreter, and any new lisp can be typed and evaluated instantly. While it is typical to modify a lisp interpreter while using it, in this case that means being able to modify StumpWM while using StumpWM, too. No need to start over, just keep going.

Additionally, StumpWM is written entirely in Common Lisp, and SBCL is written mostly with Common Lisp. Technically, that means either the Xwindow manager or the Lisp environment can be personalized with the familiarity of Common Lisp, at first without recompiling and then compiled later for a copy with permanent additions.

Personalize StumpWM with its initialization file "~/.stumpwm.d/init.lisp", such as adding keybindings or new actions. Or, include lisp from other files when starting by adding lines like:

(load "~/common-lisp/something-new.lisp")

After starting the Xserver with StumpWM as the Xwindows manager, access the Lisp interpreter anytime with "Control-t :". That is, hold the Control button then type the letter t, then let go of the Control button, then type a colon. The prompt "Eval: " will appear for typing a line of Common Lisp.

Instantly add a new keybinding for a command, or create a new Xserver window and draw in it, or add a set of new commands from any file with load. In a nutshell: an instantaneously extensible computer interface.

# Example setup of StumpWM

StumpWM: StumpWM manual. StumpWM wiki (tips and tricks).

Steel Bank Common Lisp (SBCL) 2.1.0

alexandria 1.0.1

cl-ppcre 2.1.1

Common Lisp X Interface (CLX) 0.7.5

  • CLX manual
    Likely the same as its info document viewable with Emacs.

an Xserver, f.e.


For example, piCore 12.0 (includes 64-bit version).

# Essential commands of StumpWM

There are almost a dozen essential StumpWM commands for splitting the screen area for viewing different documents and programs, and for writing Lisp computer instructions for further personalization.

StumpWM favors abbreviations for its commands (StumpWM 2. Key Bindings), short sequences of buttons for its predefined sets of instructions. One of those commands also provides a prompt for visibly typing any command name.

StumpWM uses "Control-t" as the prefix for segregating its own commands from other programs. Use the Control button in the same manner as the Shift button, t.i. hold the Control button before typing a letter (skip the hyphen), then afterwards let go of it.

Though a button sequence is invisible, typing a prefix like "Control-t" in Stumpwm changes the pointer cursor from an X or arrow into a square as an indicator until the button sequence is completed or canceled.

All StumpWM commands are in the "stumpwm:" collection. That collection name can be included for the commands, f.e. stumpwm:eval-line, but is unnecessary for them.

There are some details that might be worth noting for each of those essential StumpWM commands.

# The Lisp evaluation prompt

StumpWM provides the Lisp evaluation prompt "Eval: " by means of "Control-t :" for evaluating a single line of Lisp after the Return or Enter button is typed.

The up/down arrow buttons bring forth prior/later typed text for editing and re-using, thereby less re-typing.

Either "Meta-f" or "Alt-f" moves the text cursor forward one word, and "Meta-b" or "Alt-b" moves the text cursor backward one word. The abbreviations for more text cursor options (StumpWM 4.2) often begin with "M-" for "Meta-", but the Alt button is usually the substitute for when the Meta button is unavailable.

# Names, Lisp instructions, and errors.

A name is a placeholder that refers to memory in the computer, and anything can be stored in that memory. A Lisp instruction is a pair of parentheses with the instruction name as the first list item.

Type a name to find out whether there is information associated with it yet, or type a Lisp instruction for the computer. A message with successful results appears on the screen for a few seconds, and then conveniently disappears.

Eval: stumpwm:*input-window-gravity*
Eval: (setf stumpwm:*input-window-gravity* :center)

The delay is the number of seconds set in stumpwm:*timeout-wait* (StumpWM 4.1). However, it can also be paused by typing the prefix for a button sequence, such as "Control-t", because StumpWM is waiting for the remainder of the sequence. Finish typing the sequence and the message will likely be cleared as the next command is evoked.

Otherwise, when the name has yet to be set or the Lisp instruction is mistyped, a boring description of an error will excitingly appear and stay visible.


Almost. The error message will disappear when the next StumpWM command is evoked, or consider using "Control-t Control-g" (Essential commands) to remove the message immediately.

Eval: something
The variable SOMETHING is unbound.Backtrace for: #<SB-THREAD:THREAD "main thread" RUNNING> {1234567890}>
1: (ERR "~A" #<UNBOUND-VARIABLE SOMETHING {2345678901}>)
2: (EVAL-LINE "something")
5: ((LAMBDA (&REST #:GO &KEY :CODE :STATE &ALLOW-OTHER-KEYS) :IN "/tmp/stumpwm-20.11/events.lisp") :CODE 66 :STATE 0)
6: (STUMPWM::HANDLE-EVENT :DISPLAY #<XLIB:DISPLAY :0 (The X.Org Foundation R12008000)> ...)

 [ ...pretty much the same hereafter
   for every error message,
   except maybe different line counting,
   but nothing important... ]

17: (STUMPWM ":0")
18: ((LAMBDA NIL :IN "/tmp/stumpwm-20.11/make-image.lisp"))

The very top line above count zero is probably the most revealing, and probably enough to realize why the error happened.

The remainder bores into the processing depths of the Lisp interpreter. Likely only about the first half-dozen lines of the error, 0 through maybe 5 or so, will be relevant.

Afterwards is essentially the same for every error message. The middle reveals the constant looping that waits for typed buttons. The very end is actually how the StumpWM program itself began, as a "Lisp image".

Consider trying again with the Lisp evaluation prompt "Control-t :", then using the up arrow button to show the previous typed line, and then editing it to get a different result. Or, consider "Control-t Control-g" to clear the message from the screen.

# Optional or required collection names.

An error message claiming a name is undefined is a clue that the collection name is needed. Consider "Control-t f" for stumpwm:describe-function for querying about a instruction name, or "Control-t v" for stumpwm:describe-variable for querying about a placeholder name (New prefix for Help).

Eval: (global-pointer-position stumpwm:*display*)
The function STUMPWM-USER::GLOBAL-POINTER-POSITION is undefined.Backtrace...
Describe Function: stumpwm:global-pointer-position
Describe Function: xlib:global-pointer-position
function: global-pointer-position
(global-pointer-position DISPLAY)
Eval: (xlib:global-pointer-position stumpwm:*display*)
#<XLIB:WINDOW :0 389>
Describe Variable: stumpwm:*display*
variable: *DISPLAY*
The display for the X server
Its value is:
#<DISPLAY :0 (The X.Org Foundation R12008000)>.
Eval: (xlib:global-pointer-position *display*)
#<XLIB:WINDOW :0 389>

The feedback from the function or variable queries is a little misleading. It might print two colons when declaring the name as undefined, even when only one colon was used during a query. Otherwise, consider trying another query with two colons whenever it says it did try only one colon and failed to find anything. Also, a successful message leaves off the collection name even when it is required.

Many StumpWM names for placeholders or Lisp instructions have no need for the "stumpwm:" collection name, f.e. *top-map* or define-key. Try it and find out. However, the collection name does make obvious where to seek documentation.

When the collection name is required, sometimes an extra colon is also needed, f.e. stumpwm::read-key. That is usually because the placeholder or Lisp instruction is probably unintended for common use. The documentation for it is likely in the source file, if at all.

The StumpWM names for placeholders usually include an asterisk "*" before and after the name, f.e. stumpwm:*top-map*. That is only a convention when creating a placeholder with the defvar (CLHS). (The intended effect of defvar is essentially useless from the Lisp evaluation prompt, its intended use is for within files.) Consider a different approach for new names, distinctive for certainty.

# There can be only one.

Only one Lisp form is evaluated by stumpwm:eval-line, later forms on the line are ignored.

Consider using cons (An intro for Lisp) for pairing forms into a single Lisp instruction. The feedback will then have each result, too.

Consider multiple conses when more than two, and maybe using nil for an odd pairing.

# Customize messages and prompts


The messages and prompts from StumpWM appear when needed, each at pre-specified locations on the screen. The characteristics of text color, background color, and the border are generally shared by both messages and prompts (StumpWM 4.1).

As expected, those characteristics are adjustable with the Lisp evalution prompt.

Use setf (An intro for Lisp) to set the padding around messages and prompts, the location of messages, and the location of prompts. Note these happen to have asterisks "*" as part of their names.

   Eval: (setf stumpwm:*message-window-padding* 7)
   Eval: (setf stumpwm:*message-window-y-padding* 5)
   Eval: (setf stumpwm:*message-window-gravity* :bottom)
   Eval: (setf stumpwm:*input-window-gravity* :center)

Possible values of gravity for the messages or prompts begin with a colon ":".

   | :top-left |      |  :top   |     | :top-right |
   |___________|      |_________|     |____________|
   |                                               |
   |                                               |
   |--------          -----------         ---------|
   | :left |          | :center |         | :right |
   |--------          -----------         ---------|
   |                                               |
   |______________     _________    _______________|
   | :bottom-left |   | :bottom |  | :bottom-right |

The border width from stumpwm:set-msg-border-width and its color from stumpwm:set-border-color are absolutely consistent for prompts and all types of messages.

The prompts use the background color from stumpwm:set-bg-color and the text color (foreground) from stumpwm:set-fg-color.

   Eval: (stumpwm:set-msg-border-width 3)
   Eval: (stumpwm:set-border-color "CornflowerBlue")
   Eval: (stumpwm:set-bg-color "DarkOrchid4")
   Eval: (stumpwm:set-fg-color "Thistle1")

Acceptable color names are the X11 rgb colors (, which might be also located on the computer with the Xserver as "/usr/local/share/X11/rgb.txt".

Acceptable RGB hexadecimal numbers for the red, green, and blue hues of a color are similar to HTML colors, with an octothorpe # followed by either three or six digits.

   Hex #  0 1 2 3 4 5 6 7 8 9 A B C D E F
     Red  0 1 2 3 4 5 6 7 8 9 a b c d e #f00 or #ff0000
   Green  0 1 2 3 4 5 6 7 8 9 a b c d e #0f0 or #00ff00
    Blue  0 1 2 3 4 5 6 7 8 9 a b c d e #00f or #0000ff
   All 3                                #fff or #ffffff

For example, orange is either "orange" or "Orange". As a hexadecimal number, orange is more red than green, like "#f60", "#D40", or "#FA8038". Compare with "yellow" which is red and green somewhat equal, like "#ff0".

The colors get messy in StumpWM when it comes to its messages. There are at least three types: documentation messages, error messages, and messages with Lisp results. They use some of the eight colors listed in stumpwm:*colors*.

Documentation messages come from the help commands describe-command, describe-key, where-is, describe-variable, and describe-function. The default buttons that evoke them are listed by "Control-t h ?".

Documentation messages use the same background and text colors as the prompt, t.i. stumpwm:set-bg-color and stumpwm:set-fg-color. They also emphasize some text with the sixth color (darker and brighter) from stumpwm:*colors*. Technically, that means four colors must be coordinated legibly.

   Eval: (setf (cadr (cddddr stumpwm:*colors*)) "LightSkyBlue1")
   Eval: (stumpwm:update-color-map (stumpwm:current-screen))

Error messages use the background color from stumpwm:set-bg-color, but for the text they use the second color (its lighter version) in stumpwm:*colors*, t.i. its cadr.

   Eval: (setf (cadr stumpwm:*colors*) "DeepSkyBlue3")
   Eval: (stumpwm:update-color-map (stumpwm:current-screen))

Messages from Lisp results are temporarily displayed after using the Lisp evaluation prompt. Those messages use the background color from stumpwm:set-bg-color only for the padding around the message. The background and text colors are the darker versions of the first and third colors from stumpwm:*colors*.

   Eval: (setf (car stumpwm:*colors*) "DarkOrchid4")
   Eval: (setf (caddr stumpwm:*colors*) "Thistle1")
   Eval: (stumpwm:update-color-map (stumpwm:current-screen))

Consider using a substitute for update-color-map ( that respects the colors of stumpwm:*colors*. Just copy into a new file and modify it, then load the file with load and use the new instruction.

For example, simply changing the -0.25 to 0 ensures the first fabricated list is the exact colors specified rather than darker. Maybe drop the brightener to 0.2 for the second fabricated list, or perhaps accept more colors in an optional additional list.

# Personalize buttons for StumpWM commands

A computer does what a person desires at the mere press of a button, but for most people that is only science fiction.

[ ...introduce a buttonboard and the concept of layers of functionality for minimizing the number of buttons...

A buttonboard is typically used for writing prose or computer instructions.

Typing a button with a letter on it is typically interpreted by a computer as a command to display that letter on the computer screen, f.e. a. As a convenience, pressing and holding a modifier button before typing a letter typically results in a capital version of the letter, f.e. A.

The stumwpm:define-key assigns a button to a double-quoted StumpWM command. assign a button as a prefix to a StumpWM keymap.

... ]

# Re-assign the StumpWM prefix.

StumpWM uses "Control-t" as the prefix for abbreviations of its commands (Essential StumpWM commands). Consider keeping them, as they are relevant when reading the manual and other documentation.

Emacs (GNU) has the abbreviation "Control-x Control-t" for "transpose-lines", swapping the previous line of text (paragraph) with the current line (paragraph). Either rebind that command within Emacs, or simply use m+ in the ed text editor (GNU) (perhaps ed within Emacs "M-x shell"), or change the StumpWM prefix "Control-t" to something else, like an F button.

Eval: (stumpwm:set-prefix-key (stumpwm:kbd "F19"))

Confirm the new prefix by typing it followed by a "?" question mark to reveal the listing of buttons assigned to StumpWM commands. Note the prior prefix will be freed, thereby ignored by StumpWM and usable in other programs.

# New prefix for Help.

Prefix: F12
v     describe-variable
f     describe-function
k     describe-key
c     describe-command
w     where-is

Discover the command assigned to a button by using "Control-t h k" for describe-key. Fail to completely type the "h" and kill a program with delete-window instead. Disaster.

Consider making the Help commands more convenient, and averting a none too happy slip, by choosing a single prefix button. Check it by typing the new prefix button then the "?".

Eval: (stumpwm:define-key stumpwm:*top-map* (stumpwm:kbd "F12") (quote stumpwm:*help-map*))

Or, use the abbreviated names.

Eval: (define-key *top-map* (kbd "F12") '*help-map*)

# Personal command prefix.

Add a personal prefix (StumpWM 2.2) to segregate the StumpWM commands used personally from all the other pre-defined StumpWM commands yet to be of interest.

Pick an unused placeholder name for the "sparse keymap", then assign it with setf. Quote that placeholder for stumpwm:define-key instead of using a command name, and then the button will be a prefix for any commands assigned to that "sparse keymap".

The variable BUTTONS.MY is unbound.Backtrace...
Eval: (setf (stumpwm:make-sparse-keymap))
Eval: (stumpwm:define-key stumpwm:*top-map* (stumpwm:kbd "F20") (quote

Or more conveniently, consider shortening the names by leaving off the "stumpwm:".

Eval: (define-key *top-map* (kbd "F20") '

Choose buttons that fit comfortably with the workflow of the day or week. Consider using the up/down arrows for bringing forth the prior/next lines of the Lisp evaluation prompt for less re-typing.

Eval: (stumpwm:define-key (stumpwm:kbd "m") "run-shell-command")
Eval: (define-key (kbd "j") "pull-hidden-next")
Eval: (define-key (kbd "f") "pull-hidden-previous")
Eval: (define-key (kbd"c") "pull-hidden-other")
Eval: (define-key (kbd",") "gnew")
Eval: (define-key (kbd"k")"gnext")
Eval: (define-key (kbd"d")"gprev")
Eval: (define-key"x")"gother")

Note the double-quoted command, f.e. "pull-hidden-other", must be a StumpWM command rather than just any instruction, but it must also be written without the "stumpwm:" collection name (Optional or required collection names).

Prefix: F20
m     run-shell-command
j     pull-hidden-next
f     pull-hidden-previous
c     pull-hidden-other
,     gnew
k     gnext
d     gprev
x     gother

Type the new personal prefix and then a question mark "?" to get a listing of the abbreviations that have been assigned with that prefix. They are listed in the order they were added.

Command mode from command-mode (StumpWM 13. Miscellaneous Commands) works only with abbreviations assigned to the "Control-t" prefix. A personal prefix with buttons that make sense personally becomes more familiar.

# [ ...Custom interactive keymaps... ]

[ ...describe the effect of an interactive keymap from stumpwm:define-interactive-keymap (StumpWM 3.2). Hmm, seems like a different StumpWM manual then the "info" version? Add example... ]

[ ...describe the similarity to adding an additional layer to the buttonboard, like the effect a modifier button (Shift, Control, Alt...) provides but using a prefix button that is typed only once rather than having to hold a modifier button... ]

# Assign a button to a command.

A StumpWM command is assigned to a button with stumpwm:define-key (StumpWM 2.2). Any defined button sequence can be re-assigned to a different command, or it can be undefined by assigning the button sequence to nil instead.

Consider using the F1 through F12 buttons, probably at the top of the buttonboard. Use the describe-key command (default "Control-t h k", but consider a new prefix for Help) to check whether the desired button is already assigned to a command, and decide whether to re-assign it. That also provides the actual name for the button despite what might be on the button itself.

For example, dedicate a single button for the Lisp evaluation prompt. The original button sequence for eval-line of "Control-t :" will still be available, too. A successful result from stumpwm:define-key is NIL rather than an error.

Eval: (stumpwm:define-key stumpwm:*top-map* (stumpwm:kbd "F5") "eval-line")

The stumpwm:*top-map* bypasses the need for the StumpWM prefix "Control-t", instead type only the declared button to activate the command. The stumpwm:kbd instruction converts the double-quoted name of a button.

Note the double-quoted command must be a StumpWM command rather than just any instruction, but it must also be written without the "stumpwm:" collection name (Optional or required collection names).

StumpWM also provides a prompt for visibly typing commands with colon ambiguously assigned to "Control-t ;" (a semicolon). Consider adding another button for it, also without a prefix.

Eval: (stumpwm:define-key stumpwm:*top-map* (stumpwm:kbd "F6") "colon")

Consider reviewing the full command listing for discovering other commands. Use the aforementioned colon command prompt itself by typing the word commands at its prompt ": ", then type the Return or Enter button.

Note on paper anything interesting, then clear the listing from the screen with "Control-t Control-g" (Essential commands). Find out more about a command with describe-command as "Control-t h c", or from the StumpWM command and function index.

# Custom commands.

[ ...describe defining a button for eval-line along with custom Lisp instructions. stumpwm:define-key requires a double-quoted StumpWM command, so this is how to bypass that requirement and use any function. Also, more than one form... ]

# An intro for Lisp with StumpWM

At the core of Lisp is a paragon of lists, either empty or efficiently multi-dimensional, because Lisp is "LISt Processing".

Like a notepad of paper, one of the basic experiences with a computer is memory management. A label or short phrase such as a heading becomes a concise summary for a paragraph or section, a reminder of the content for quickly skimming or referencing by name later. Similarly, keeping an improvised index listing on the back pages of a notepad helps with cross referencing a list of topics with their page numbers.

[ In fact, it is generally a good idea to have a notepad of paper next to a computer for making notes on how to operate the computer, too. Computers rarely come with manuals nowadays. ]

Lists are readily notated parenthetically: ( ). Additionally, there are computer actions for constructing a list from a pair of items, for referencing an item in a list, and for associating a name to a list.

A "Lisp form" is just text written (t.i. formatted) in a way that is readable by the Lisp interpreter. Some examples are a quoted symbol (with quote), double-quoted text (with " "), a quoted parenthetical Lisp form (with quote), a parenthetical Lisp form for its evaluation results, or a number.

An instruction for the computer is written as a Lisp form, a parenthetical list beginning with a name for a computer action. That name is followed by any additional info needed for functioning in that manner.

There are about a half-dozen important Lisp functions, t.i. named instructions.

A Lisp form can also be double-quoted text such as for messages, or a name for a Lisp symbol associated with another Lisp form.

Decimal system numbers can begin with a - or +. A hexadecimal number begins with #x, then can have a - or +, then is followed by a group of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f; capitalized is okay. A binary number begins with #b, then can have - or +, then is followed by a group of 0 or 1.

The Lisp interpreter prints a number as a decimal number, and without a +. For example, either 12 or #xC or #b+1100 is shown as 12.

The "Eval: " prompt for Lisp instructions is from the stumpwm:eval-line command with "Control-t :" (The Lisp evaluation prompt). Type the name of a Lisp symbol to reveal whether it is associated with anything, or type a Lisp instruction for the computer.

Eval: something
The variable SOMETHING is unbound.Backtrace...
Eval: (quote something)

quote: Suppress immediate evaluation of a legitimate Lisp form. Commonly abbreviated to one single quote mark ' instead, especially in messages with results or feedback from the Lisp interpreter.

Though evaluation is suppresed, the quoted item is expected to be a legit Lisp form, otherwise the Lisp interpreter (SBCL) complains. For example, a quoted legit placeholder name is acceptable even when yet to be used. However, a colon in the middle of a placeholder name indicates it is a Lisp instruction name and it must already exist, otherwise an error is shown.

Eval: (quote something)
Eval: 'something
Eval: something
The variable SOMETHING is unbound.Backtrace...
Eval: (quote (quote something))
Eval: (quote (cons 'something 'more))
Eval: (quote ('something . 'more))

cons: Construct a new list by pairing two Lisp forms (Lisp lists are pairs).

Keep in mind the Lisp interpreter messages have abbreviated notation when a list is the dexter of a list, which is also the abbreviation of nil as its dexter because nil is a list even though it is empty "( )".

Eval: (cons "Two words." (quote a-name))
("Two words." . A-NAME)
Eval: (cons 3 '("Two words." . a-name))
(3 "Two words." . A-NAME)
Eval: (cons 'something nil)
Eval: (cons ( ) 'something)

cdr: [just say "c-d-r", or "dexter"] Call up the dexter reference of a list, t.i. its right half.

Eval: (cdr (quote ((1 . 2) . 3)))

car: Call up the abdexter reference of a list, t.i. its left half.

Eval: (car '((1 . 2) . 3))
(1 . 2)

eval: Evaluate a Lisp form, especially a Lisp form quoted with quote, or a placeholder name referencing a Lisp form.

Eval: '(cons 1 2)
(CONS 1 2)
Eval: (eval '(cons 1 2))
(1 . 2)
Eval: (setf later.test '(cons 1 2))
(cons 1 2)
Eval: later.test
(cons 1 2)
Eval: (eval later.test)
(1 . 2)

setf: Associate a name with the evaluation of a Lisp form, such as double-quoted text or the results of a command function. Or, associate the position of a list with such an evaluation, such as setting the car of the list. In essence, assigning the temporary memory of the Lisp interpreter.

Eval: prose
The variable PROSE is unbound.Backtrace...
Eval: (setf prose "A list of characters." a-list '(10 . 9))
(10 . 9)
Eval: prose
"A list of characters."
Eval: a-list
(10 . 9)
Eval: (setf (cdr a-list) 4)
Eval: a-list
(10 . 4)
Eval: (setf do-it (quote (setf (car a-list) 15)))
Eval: do-it
Eval: a-list
(10 . 4)
Eval: (eval do-it)
Eval: a-list
(15 . 4)
Eval: do-it

# Reading and writing within the Lisp interpreter

The means for associating a nickname with information on a computer has generally been obscure with the software pre-installed on it. However, a Lisp interpreter such as SBCL used by StumpWM makes it straightforward with the Common Lisp setf macro (CLHS). Any information can be noted within the Lisp interpreter by associating a label with it.

remember "Something to remember."
a-name   "And one more thing.")

Nonetheless, that, too, is obscured as Common Lisp has 978 symbols of its own, including variables, functions, and macros. For whatever reasons, many implementations of Common Lisp (such as SBCL) have implemented everything as if the Common Lisp specification was an assignment.

As aforementioned (The Lisp evaluation prompt), the evaluation prompt provided by "Control-t :" in StumpWM waits for only a single line, suitable for a quick short note.

Eval: (setf a-symbol "A name is a Lisp symbol.")
"A name is a Lisp symbol."

To see the information again, simply type the name in the evaluation prompt again and type the Return or Enter button. The name, a Lisp symbol, will be evaluated and once again a message with the result will be displayed for a few seconds, then disappear again.

Eval: a-symbol
"A name is a Lisp symbol."

As noted about Lisp and NIL, the final item in every parenthetical list is denoted by a space-separated dot, t.i. a period. The final list item is typically nil, so for brevity such lists are typed or printed without it, as mentioned in Lisp lists are pairs. Therefore, a list without a dotted final item actually does have one, and in that case it is nil.

Therefore, a straightforward way of converting a named symbol with a single item into a list for itself is pairing it with nil, and re-using its name. Notice from the message that the Lisp interpreter favors printing the abbreviated form, without the dotted nil.

Eval: remember
"Something to remember."
Eval: (setf remember (cons remember nil))
("Something to remember.")
Eval: remember
("Something to remember.")

Replace with a new list from the cons function by pairing the new information with the list itself.

Eval: (setf remember (cons "Curiosity more than expectations." remember))
("Curiosity more than expectations."
 "Something to remember.")
Eval: (setf remember (cons a-name remember))
("And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")
Eval: (setf remember (cons a-symbol remember))
("A name is a Lisp symbol."
 "And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")
Eval: (setf remember (cons "A quick note: write questions on paper." remember))
("A quick note: write questions on paper."
 "A name is a Lisp symbol."
 "And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")
Eval: remember
("A quick note: write questions on paper."
 "A name is a Lisp symbol."
 "And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")

Multiple car and cdr references can be abbreviated up to four places, as mentioned in Lisp lists are pairs. For example, a reference to the car of the cdr of a list can be from the abbreviated cadr function, t.i. the "a-d" of the list. As noted about Lisp and NIL, a list without a dotted final item actually does have one, and in that case it is nil.

Eval: (car remember)
"A quick note: write questions on paper."
Eval: (cdr remember)
("A name is a Lisp symbol."
 "And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")
Eval: (car (cdr remember))
"A name is a Lisp symbol."
Eval: (cadr remember)
"A name is a Lisp symbol."
Eval: remember
("A quick note: write questions on paper."
 "A name is a Lisp symbol."
 "And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")
Eval: (cddddr remember)
("Something to remember.")
Eval: (car (cddddr remember))
"Something to remember."
Eval: (cdr (cddddr remember))

The information is accessible only while the Lisp interpreter exists, so it will be gone after quitting StumpWM or turning off the computer. On the other hand, there are ways of removing parts of a list, and without turning off the computer.

Recall the setf instruction can set the value for a position in a list (An intro for Lisp), t.i. either the car or the cdr of the list. That makes leaving out an item simple, which is the same as removing it.

Eval: remember
("A quick note: write questions on paper."
 "A name is a Lisp symbol."
 "And one more thing."
 "Curiosity more than expectations."
 "Something to remember.")
Eval: (car (cdr (cdr remember)))
"And one more thing."
Eval: (cdr (cdr (cdr remember)))
("Curiosity more than expectations."
 "Something to remember.")
Eval: (setf (caddr remember) (cdddr remember))
("Curiosity more than expectations."
 "Something to remember.")
Eval: remember
("A quick note: write questions on paper."
 "A name is a Lisp symbol."
 "Curiosity more than expectations."
 "Something to remember.")

# Reading and writing with the computer medium

Write information to a document in computer memory so it will be available the next time the computer is turned on (if it successfully restarts) by using with-open-file (CLHS) along with pprint (CLHS) for "pretty printing".

The with-open-file instruction has a plethora of options because it uses open (CLHS), so focus on what is desired. For example: write to a document; create the document when non-existent; append to the document when it does exist.

(to-the-doc-from-WOF "/actual/name/for/document"
:direction :output
:if-does-not-exist :create
:if-exists :append)
(pprint "What you can do, while weeping."

It turns out this makes the eyes water, as it is a bit much to be typing into the Lisp interpreter every single time, and the StumpWM evaluation prompt handles only one line at a time. However, a Lisp list is conveniently constructed one pair at a time (Lisp lists are pairs).

Consider writing on paper a list of instructions for writing to a document, then noting the parts.

(WOFdoc "/actual/name/of/doc"
:direction :output :if-does-not-exist :create :if-exists :append)
(pprint "Less weeping." WOFdoc) )

That list of Lisp instructions is essentially a list of three items.

  1. The name of the function for the instruction list: with-open-file.

  2. A list of paired info for with-open-file. First, a placeholder for when the file is opened successfully, followed by the location and document name, which is required. Additional pairs of option names and their values are afterwards.

  3. The pprint instruction list. It prints any quoted Lisp form, such as double-quoted text or the results of Lisp instructions. At that is the reference to the opened file provided by the placeholder declared in the list of paired info for with-open-file.

One approach is by constructing each sublist separately using quote (An intro for Lisp), or its abbreviated form as one single quote mark ', to write as much as comfortably possible at the evaluation prompt. Associate a placeholder name for each with setf.

Eval: (setf wof-options '(WOFdoc "/actual/name/of/doc" :direction :output :if-does-not-exist :create :if-exists :append))
Eval: (setf the-printer '(pprint "Divide and concoct." WOFdoc))
(PPRINT "Divide and concoct." WOFDOC)

A confirmation message from the Lisp interpreter prints the names of Lisp symbols with all uppercase letters. That is partially because the Lisp interpreter acknowledges only one case for letters in symbol names, and the convention of the Lisp interpreter is to reveal that by printing Lisp symbols as having uppercase letters.

Of course, that means symbol names varying only by case all reference the same symbol assigned to the same information. For example, the Common Lisp instruction names can be typed with whatever case desired and the Lisp interpreter will be fine with that, such as Format or FORMAT or fOrMat, and so on.

A Lisp instruction is an abdextral constructed list (Lisp lists are pairs), but also always begins with nil as its dexter. As it is leftwardly constructed, each additional part is the left half of the pair and the gradually forming list is always the right half.

Remember, using the up/down arrow buttons within the evaluation prompt provided by StumpWM brings forth prior/later typed text for editing and re-using, thereby less re-typing.

Eval: (setf write-to-doc-recipe (cons the-printer nil))
((PPRINT "Divide and concoct." WOFDOC))
Eval: (setf write-to-doc-recipe (cons wof-options write-to-doc-recipe))
(PPRINT "Divide and concoct." WOFDOC))
Eval: (setf write-to-doc-recipe (cons (quote with-open-file) write-to-doc-recipe))
(PPRINT "Divide and concoct." WOFDOC))

The name is just a placeholder for the list of Lisp instructions, so the name by itself just reveals what it references.

Eval: write-to-doc-recipe
(PPRINT "Divide and concoct." WOFDOC))

Evaluate what the placeholder references by placing it in an instruction list using eval (An intro for Lisp). The double-quoted text listed with the pprint instruction will be written to the document named with the overall with-open-file instruction.

Eval: (eval write-to-doc-recipe)

[ ...describe the Lisp instructions for reading from a document, perhaps with read (CLHS), though it is a little bit tricky to view a whole document... ]

[ ...describe the delete-file (CLHS) instruction for deleting the files... ]

   (delete-file "/name/of/file")

Whenever desired, either change what to write to the document or change the document name with setf (An intro for Lisp). Query the parts of the recipe for confirmation of the correct place to change before changing it.

Eval: write-to-doc-recipe
(PPRINT "Divide and concoct." WOFDOC))
Eval: (car (cdr write-to-doc-recipe))
Eval: (cadr (cadr write-to-doc-recipe))
Eval: (setf (cadr (cadr write-to-doc-recipe)) "/another/doc")
Eval: (caddr write-to-doc-recipe)
(PPRINT "Divide and concoct." WOFDOC)
Eval: (cadr(caddr write-to-doc-recipe)))
"Divide and concoct."
Eval: (setf (cadr (caddr write-to-doc-recipe)) "This is something else.")
"This is something else."
Eval: write-to-doc-recipe
(PPRINT "This is something else." WOFDOC))

Optionally, use setf to replace the text in the instructions with a placeholder. Thereon, use setf to change the placeholder instead of the Lisp instructions. Optionally, insert a placeholder in the instructions for the document name, too.

Eval: (setf (cadr (cadr write-to-doc-recipe)) (quote doc-for-writing))
Eval: (setf (cadr (caddr write-to-doc-recipe)) (quote text-to-write))
Eval: write-to-doc-recipe
Eval: (setf doc-for-writing "/and/another/doc")
Eval: (setf text-to-write "Something for another document.")
"Something for another document."
Eval: (eval write-to-doc-recipe)
Eval: (setf text-to-write "And some more.")
"And some more."
Eval: (eval write-to-doc-recipe)

[ ...describe a setf instruction that will set the contents of the recipe to a placeholder write-to-doc... ]

   (setf recipe-for-later (cons write-to-doc-recipe nil))
   (setf recipe-for-later (cons 'write-to-doc recipe-for-later))
   (setf recipe-for-later (cons 'setf recipe-for-later))

[ ...Therefore that instruction sets a placeholder named write-to-doc to the contents of the recipe. Write that setf instruction to a document, then it can be read by the Lisp interpreter later with the load instruction. No need to type the recipe again and it is readily used with eval. ... ]

[ ...Typing the name in the evaluation prompt reveals the recipe. That shows the document name and text to write both have placeholders in the recipe for easily changing without needing to modify the recipe. ... ]

Ultimately, choose a new document name for writing these Lisp instructions. [ ...refer to the previously described new symbol with new instructions... ] Evaluate the instructions again and this recipe is written to the chosen document.

Eval: (setf doc-for-writing "/doc/for/this/recipe")
Eval: (setf text-to-write recipe-for-later)
Eval: (eval write-to-doc-recipe)

[ ...describe using load for reading it from the document. Or, maybe with read then eval... ]

# X Window System and its protocol

# A translation of a misnamed paradigm.

A "window" is a misnomer for a designated area, typically rectangular. An area is simply the coordinates for its left-top corner associated with its width and height (rather than its kittycorner coordinates): (x, y) (w, h).

Various shapes within an area are displayed by declaring two different colors (background and foreground), the type of shape, and the method of merging the intersection with other prior drawn shapes within the same area. That is, each area constrains its own content, but shapes merge by a variety of methods (sixteen) within the area, f.e. merging of a red shape and a blue shape can make their intersection purple.

Abutting each designated area along their edges is akin to tiling the areas, such as when creating split-views. The X Window System protocol limitedly supports intersection of the designated areas themselves by means of a single priority list for the areas. Intersecting areas of higher priority are subtracted from areas of lesser priority, like what remains as each area is cut from a piece of paper.

Therefore, the designated area that has the highest priority maintains its rectangular shape because it has no intersecting areas subtracted from it. The other areas maintain their shape when intersecting only lesser priority shapes, if any intersection at all. This also implies there is no true transparency effect for an area, because designated areas are only subtracted and never merged.

In other words, the designated areas are meant to be rectangular and their intersections are subtracted, whereas a variety of additionally described shapes can merge with each other within a single designated area.

Furthermore, a designated area can have areas designated within its bounds prioritized amongst themselves, but those internal areas are forbidden from extending beyond the outer area. Obviously, those subregions are intersecting with whatever shapes have been described within the overall area, but only by means of subtraction because they are designated areas instead of shapes.

A pixmap, t.i. a picture map, is a simple list of dots (pixels) associated with a color for each dot. The content of a designated area can be exported as a pixmap. A pixmap can be applied fully or partially anywhere within any area, and can be assigned as the background of any area. The Xserver automatically applies the background of a designated area for the pixels that area has priority, but any other described content is managed separately by external software (t.i. a client) when it receives notifications from the Xserver.

An intersection is visibly changed by the higher priority area for that intersection. As such, a designated area with no content and no background seemingly acquires all pixels within its boundaries from either the overall backdrop of the Xserver or from lesser priority areas, with no further visible changes from modifications of intersections with lesser priority areas.

# Discover keycodes for buttons.

Each button on a buttonboard has an id often known as a "keycode". A symbol or icon on a button is often known as a "key symbol" or "keysym". Associating a keysym with a keycode is often known as "keymapping". Changing the keysym associated with a keycode is often known as "remapping".

The Xserver keeps a list of keycodes for the buttons on a buttonboard, and each keycode is associated with seven keysyms (U.S. English). For example, the button labeled with "A" likely has the keysyms for at least "a" and "A".

Use the Lisp evaluation prompt to discover the keycode for a button after it is typed by using the xlib:grab-key, the stumpwm::read-key (two colons!), and the xlib:ungrab-key functions.

Eval: (xlib:grab-key (stumpwm:screen-root (stumpwm:current-screen) :any))
Eval: (stumpwm::read-key)
(66 . 0)
Eval: (xlib:ungrab-key (stumpwm:screen-root (stumpwm:current-screen) :any))

The stumpwm::read-key instruction (StumpWM input.lisp, 262–267) reveals the keycode for the next button pressed, paired with a number representing which modifiers were active. No prompt. Only the keycode (the left half) is useful for the purpose of remapping. A button used as a modifier, like Shift, will reveal its own keycode when it is pressed by itself.

Eval: (stumpwm::read-key)
(28 . 4)
Eval: (car (stumpwm::read-key))

However, StumpWM normally grabs only the keys that were defined for commands, like the "Control-t" prefix. According to the documentation for xlib:grab-key, use :any (with the colon) as the keycode for accepting any button pressed.

The xlib:grab-key needs both an Xwindow and a keycode, and then returns a number that has nothing to do with keycodes, so ignore that number. StumpWM provides screen-root for extracting the root Xwindow from the results of the current-screen instruction. The root Xwindow for the current screen is often appropriate for generic introspection like this.

Predictably, specifying :any like this means StumpWM will notice any button pressed. Thereby, StumpWM will seek a command defined for each, and provide a message each time that fails. Obviously, this interferes with using other programs. Conveniently, StumpWM ceases looking for commands whenever it provides a prompt, like for Lisp evaluation.

In the mean time, use stumpwm::read-key from the Lisp evaluation prompt. It will now reveal the keycode for the very next button pressed, even for a button like Caps Lock. Write on paper the label on the desired button, press the button, then write on the paper the keycode (the left half) that is revealed. Keycodes are often somewhat sequenced from left to right, top to bottom on a buttonboard.

Use stumpwm::read-key again for another button, or use the xlib:ungrab-key instruction with the exact same info that was given to xlib:grab-key to return typing to normal. Just like xlib:grab-key, the xlib:ungrab-key produces an arbitrary number, no need to record it.

The only difference between the grab/ungrab instructions is the "un" of xlib:ungrab-key. Recall, the up/down arrow buttons in the evaluation prompt reveal the prior/next lines that were typed, for less re-typing (the Lisp evaluation prompt). The Home button or "Control-a" moves the text cursor to the beginning of the line in the prompt quicker than the left arrow button.

For a bit more convenience and less clutter in the prompt history, assign a button to a command using eval-line with stumpwm::read-key (because it is was defined with defun rather than defcommand). Then, just press that button to evoke the command instead of using the Lisp evaluation prompt each time.

Eval: (stumpwm:define-key stumpwm:*top-map* (stumpwm:kbd "F16") "eval-line (car(stumpwm::read-key))")

# Change button symbols for keycodes.

[ ...rewriting... need for "xmodmap", there are at least two simple approaches, either with aref or a foldy, while using CLX... ]
[ ...hmm, Xserver seems unaffected by the change...and sometimes StumpWM crashes...see xlib:change-keyboard-mapping pecularities... ]

Use the work-on-a-copy approach: obtain a copy of a current setting, modify the copy, replace the current setting with the modified copy.

The xlib:keyboard-mapping (CLX 15.4.2) provides a copy of each keycode (0–255) and its keysyms (probably seven each).

The variable KEYMAP.MY is unbound.Backtrace...
Eval: (setf stumpwm:*display*))
#2A((0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (65307 0 65307 0 0 0 0)
 (49 33 49 33 0 0 0)
 (50 64 50 64 0 0 0)

The xlib:keyboard-mapping provides a two-dimensional array. An array looks like a list of lists preceded by an octothorpe "#" and its number of dimensions, but an array is accessed or modified with only array instructions (CLHS 15.2 The Arrays Dictionary).

Congruently, the xlib:change-keyboard-mapping (CLX 15.4.2) requires a two-dimensional array. It is also important to specify the :end as 255, or the final keycode.

Eval: (xlib:change-keyboard-mapping stumpwm:*display* :end 255)

The aref (CLHS) gives the array reference for an item when given its position for each dimension. The position is the number of other items before the desired item, for each dimension from outside to inside. For example, there are zero items before the first item so it is at the zeroth position, there are forty-two items before the forty-third item so it is at the forty-second position, and so forth.

The two-dimensional keycode array is sized as [256 7], so the array indices are 0–255. That allows for the subrange of 8–255 to match exactly with the keycodes 8–255, so specifying the keycode number is conveniently the same as the array position. The extra few at the beginning are of no matter.

The seven keysyms are referenced by 0–6 for the second dimension by the conventional skip-index approach. So, skip 0 items for access to the first keysym, skip 1 item for access to the second, and so on.

Eval: (aref 66 0)
Eval: (setf (aref 66 0) #xff0d)
Eval: (aref 66 0)

It might be more convenient to replace a whole list of keysyms for a keycode rather than change each of its keysyms individually.

Convert the two-dimensional array of individual keysyms into a one-dimensional array of lists of keysyms with write-to-string (CLHS), then read-from-string (CLHS), and then make-array (CLHS).

The write-to-string converts any Lisp form into double-quoted text. The read-from-string converts double-quoted text into a Lisp form, but can also skip characters at the beginning and ending. Simply skip the description of the array, t.i. the text before the first parenthesis.

Eval: (setf (write-to-string
"#2A((0 0 0 0 0 0 0)...)"
Eval: (setf (read-from-string nil nil :start 3))
((0 0 0 0 0 0 0)...)

The read-from-string has two other options prior the options to skip characters. Just provide nil for each before specifying :start for skipping the first three characters ("#2A") of the text. It then becomes an ordinary list of lists.

Give the make-array the number of items of only the outer list to make a one-dimensional array. Either presume 256 keycodes, or confirm with length (CLHS). The result will be a list prepended with an octothorpe, indicating it is actually an array.

Eval: (length
Eval: (setf (make-array '(256) :initial-contents
#((0 0 0 0 0 0 0)...)

The solitary octothorpe is the abbreviation for "#1A", a one dimensional list. That means this is now an array of lists, so a whole list of keysyms is accessible and replaceable with aref. Individual keysyms are still accessible and replaceable within the lists, but by means of cdr and car.

Eval: (aref 66)
(65293 0 65490 0 0 0 0)
Eval: (setf (aref 66) '(#xff0d 0 #xff0d 0 0 0 0))
(65293 0 65293 0 0 0 0)
Eval: (cadr (aref 66))
Eval: (setf (cadr (aref 66)) #xff09)
Eval: (aref 66)
(65293 65289 65293 0 0 0 0)

Ultimately, the keycodes need to be a two-dimensional array for xlib:change-keyboard-mapping. Use the same technique: write as text, read the text without the array prefix, make a new array from the list of lists. Recall, count, or confirm with length there are 7 items for the second dimension.

Eval: (setf (write-to-string
"#((0 0 0 0 0 0 0)...)"
Eval: (setf (read-from-string nil nil :start 1))
((0 0 0 0 0 0 0)...)
Eval: (setf (make-array '(256 7) :initial-contents
#2A((0 0 0 0 0 0 0)...)
Eval: (xlib:change-keyboard-mapping stumpwm:*display* :end 255)

[ ...See xlib:change-keyboard-mapping pecularities... ]

[ ...likely the modifier buttons section... ]

[ ...

The U.S. English buttonboards have 47 buttons for letters and symbols. Typically, holding down the Shift modifier button signals the computer to provide another 47 alternate symbols, such as capital letters and more punctuation.

The Control and Alt modifier buttons individually provide 47 additional alternate possibilities each. Holding two modifier buttons at the same time is another distinct signal for the computer for three more sets of 47 possibilities: Shift+Control, or Shift+Alt, or Control+Alt. Holding all three is yet another 47 possibilities.

Eight layouts overall, each providing 47 possibilites, totals a minimum of 376 possibilities. That is a minimum because there are other buttons, like F1–F12 or Home/End/Help or Tab/Return/Space or arrow buttons and more, and all can be combined with any combination of modifier buttons.

As such, there really is no need for so many (three!) modifier buttons. Also, a modifier button held with a thumb enables typing with the other fingers of the same hand, thereby making two of each modifier redundant.

... ]

[ ...some ideas or inspiration... ]

[ ...

Consider swapping "QWE" for the familiar sequence "ABC", or "123" to "012". Make the caps lock button the prefix for commands. Consider putting the braces "( )" (unshifted) and brackets "[ ]" (shifted) in the center at T Y (left and right), maybe the comma/double-quote at G and period/apostrophe at H, and rearrange the letters some.

Consider having the hands one row up, thereby the thumbs can easily type the buttons on the bottom row above the barbutton. Make each of those bottom buttons a space button and Return, and one each of Shift, Control, and Alt.

Consider rotating the buttonboard 180 degrees. The function buttons F1–F12 are then physically at the bottom for the thumbs. Assign a function button for the new space button, a new Return button, and single modifier buttons for Shift, Control, and Alt. Assign "Return" to a button somewhere left of the space button, since that is what each actually does anyway.

In essence, make it familiar and personally convenient, or continue using what was manufactured for no one in particular. Different is okay, likely no one else will ever notice, as it is a personalized computer. Either way, consider keeping notes on paper for each layout associated with each modifier button.

... ]

# Common Lisp X Interface (CLX)

For now, these are attempts at unraveling some obstinate functions of the Common Lisp X Interface, because every programming fad on the planet was used to implement any and every part, likely in the name of "modern programming" or "robustness". To be fair, many of the fads were in the Common Lisp HyperSpec, rather than as a separate set of approaches (like a cookbook).

On the other hand, some paradigms from other computer programming writing systems (misnomered as "computer languages") were prostheticized into CLX for the sake of whomever wrote it. That is fine, except there is no workflow or intent included, so there is no record of actual usage, no shared experience, and so no inspiration for extensibility.

Let it be made clear: There is no extensibility from "extended". The latter is merely the footprint of a dinosaur, what the computer manufacturers and operating system companies provide for free (extendedness) with the fantasies (marketing) they sell in the name (branding) of their own personal charities (online stores).

Source code is worthless when there is too much of it. Modular is only worthwhile when actually used, rather than made "just in case" or to fluff out all the possibilities.

Prefabricated is lifeless and unadaptable. Lack of intent and real world usage is uninformative and uninspiring. Perfectness itself never sits still and it is pointless as a goal, but is experienced in the flow of everyday life, beyond the dead written past of history or the freshly mummified bleeding edge computer programs.

Both CLX and Common Lisp were clearly too much for the people involved in writing them to handle, and they did the best they could with those two behemoths. They can only be torn apart, most of the pieces thrown aside, and maybe something familiar and inspiring will provide an outlet for ingenuity. They are clearly worthless for the everyday individual, for they are unspokenable by the vernacular of the layman and fail to fit with what emerges from the split second moment of life.

# xlib:change-keyboard-mapping pecularities.

For whatever reason the Xserver seems to be unaffected by the changes from xlib:change-keyboard-mapping (CLX 15.4.2). CLX documentation says use NIL for NoSymbol, though X11 protocol says zero is fine. NIL sometimes produces an error. Zero is without error, but so far the changes to zero for the first keysym position for a keycode are unchangeable thereafter.

Most notable is an "unsigned byte 8" error occurring for values greater than 255 for :end, possibly from type checking done with the functions/macros named with the prefix "index..." that are from text.lisp of CLX source.

The xlib:keyboard-mapping returns an array sized as [256 7] by default, and is therefore unreturnable to xlib:change-keyboard-mapping because its :end is documented as (array-dimensions keysyms 0) by default, t.i. 256.

xlib:change-keyboard-mapping breaks (xlib::display-keysym-mapping stumpwm:*display*) sometimes by leading to 20 entries per keycode rather than just 7, and at other times inserts the wrong keysyms for a keycode.
The source code requires :end be one more than the final keycode because length equals ":end - :start", but it also rejects 256 as a value for including the final possible keycode 255, t.i. only 0–254 is possible even though 8–255 is what is specified in the X protocol.
A potential workaround is to provide a smaller array, such as [248 7] for 8–255 (seven keysyms each), and specify :first-keycode as greater than 0, such as 9 (typically the first on the buttonboard anyway, as Escape). Then :start is 0 and :end is number of keycodes plus one. However, additional testing suggests a smaller array fails.

The REWRITE would be to make :end be the actual final keycode position in the supplied array, then have the function calculate the count inclusively of the specified indices by ":end - :start + 1", and have the loop cease at ">" rather than ">=".
But xlib:change-keyboard-mapping fails to make correct changes, so there is no point normalizing its interface. It simply needs to be abandoned (or the funicular spaghetti code further untangled).
The xlib:process-event (CLX 13.2) documentation points out the CLX cache of keysyms needs to be invalidated, and that xlib:mapping-notify (translate.lisp: 494,506) is for helping with that. However, the latter takes four values and there is no example workflow. Prior experience and knowledge and intent is just supposed to be magically known for a custom CLX function with an indirect relation to the X protocol. Internally, there are just two significant lines, the most notable being (setf(xlib::display-keysym-mapping stumpwm:*display*)nil), which seems to have no effect when used from the Lisp evaulation prompt provided by eval-line from StumpWM. But that apparent ineffectiveness might be because of the failure or incorrect usage of xlib:change-keyboard-mapping (presuming there is a correct way of using it).

When no error or crashing, ineffectiveness is confirmed with xlib:keycode->keysym (CLX 15.4.3).

Eval: (xlib:keycode->keysym stumpwm:*display* 66 0)

But, confirmed it does work with prior xmodmap instructions:

(stumpwm:run-shell-command "xmodmap -e 'keycode 66 = Return Tab'")

However, consider changing keycode 66 to the keysyms for Return (#xff0d) and Tab (#xff09) with the xlib:change-keyboard-mapping. StumpWM crashes, but at the console. [StumpWM seems unrestartable after killing it, just repeats the same error at the console. Seem to need to kill both StumpWM and Xserver, then restart them, then everything seems fine again.]

Eval: (xlib:change-keyboard-mapping stumpwm:*display* (make-array '(1 7) :initial-contents '((65293 65289 65293 65289 0 0 0))) :first-keycode 66 :start 0 :end 1)

Or, consider swapping "@" (keysym 64) with "2" (keysym 50) for its typical keycode 11. Normally, the keysyms are (50 64 50 64 0 0 0). No error, and there is a change for keycode 11, but to all zeros, meaning there is now no way to type "2" or "@" (hence why it was chosen as a test rather than "1", so its keycode could be typed in the prompt afterwards).
[Hmm, does it really want an array with at least that many keycodes? If so, then the aforementioned workaround of using a smaller array simply avoids the error without ever being possible to set all keycodes.]

Eval: (xlib::disply-keysym-mapping stumpwm:*display*)
#2A((0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (65307 0 65307 0 0 0 0)
 (49 33 49 33 0 0 0)
 (50 64 50 64 0 0 0)
Eval: (xlib:change-keyboard-mapping stumpwm:*display* (make-array '(1 7) :initial-contents '((64 50 64 50 0 0 0))) :first-keycode 11 :start 0 :end 1)
Eval: (xlib::disply-keysym-mapping stumpwm:*display*)
#2A((0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (0 0 0 0 0 0 0)
 (65307 0 65307 0 0 0 0)
 (49 33 49 33 0 0 0)
 (0 0 0 0 0 0 0)
Eval: (xlib:keycode->keysym stumpwm:*display* 11 0)

Sometimes there is an error at the console with varying number for "the value". StumpWM crashes (maybe?) as it is no longer available, but ps shows its process still listed.
Rather repeatable, something to do with attempting to change keyboard mapping more than once, perhaps when trying something different. Try 12 keycodes in array with only two keysyms, t.i. size of [12 2], and include the first 12 keycodes, but specify only :first-keycode 11, :start 0, :end 1.
[ Ran out of room on paper...write the rest next time. ]

Caught 'The value
        is not of type
          (UNSIGNED BYTE 29)' at the top level. Please report this...
0:(XLIB::AREF-CARD29 #<unavailable argument> #<unavailable argument>)

Perhaps re-check stumpwm:handle-event (StumpWM events.lisp: 634,671) and the :mapping-notify handler (StumpWM events.lisp:380,385), as StumpWM might be causing interference. The latter is evoking stumpwm:update-modifier-map (StumpWM input.lisp: 836,838; but consider 796,838). (Note: personal keymap has no Meta, and StumpWM does something special when that is the case.) Probably just a distraction from the main concern of xlib:change-keyboard-mapping.

Restarts are advertised but impossible. Afterwards, there is a reference to the CLX source, though it claims the file has been modified since compilation (doubtful).

(XLIB::AREF-CARD29 #<unavailable argument> #<unavailable argument>)
; File has been modified since compilation:
;   /.../common-lisp/clx-0.7.5/dependent.lisp
; Using form offset instead of character position.
   source: (THE CARD29 (ASH (THE CARD8 (AREF A (INDEX+ I +LONG-2+))) 16))

# Modifications for StumpWM

The most immediate change to StumpWM is applied with the eval-line command (the Lisp evaluation prompt), available with Control-t then colon, usually notated as "C-t :".

That is also the means for loading a file with a more comprehensive change written with Common Lisp, by using the load function. For example:

(load "~/.stumpwm.d/custom/points-later.lisp.html")

The ".lisp" suffix is common for files with Lisp, but is optional because Lisp is just plain text, just like HTML and CSS.

# Alternative for pointer activation.

The basic pointer activation in StumpWM (the Xwindow manager formerly known as "ratpoison") depends on a legacy function named "ratclick", which might fail when the source and version of the CLX library is without support for the XTEST extension for the Xserver. Even when it is supported, the function name might be different than what is requested by StumpWM:

For example, the actual function needed has been in the CLX "test/" directory, and from there will be known instead as:

Perhaps edit a new text file (in whatever text editor) and make a new StumpWM command (3.1 Writings Commands) using that xlib function for the desired button: 1 for the primary button, and 3 for the secondary button. Documentation can be nice, too, when querying help for the function with "C-t h f". After loading the file, the command will be available, or errors (red message text) will be reported (so edit and load again).

(stumpwm:defcommand activate-pointer
((:number "Pointer button number (1-5): "))
"Press and release a specific pointer button.

Use 1 as the button-number for the primary button,
and 3 as the secondary button (a.k.a. right-click)."
The xlib/test function also requires
 the current display.  That is provided
 by StumpWM as *display*.
;; First, press the button.  Requires t.
stumpwm:*display* Fbutton-number t)
;; Then release the button.  Requires nil.
stumpwm:*display* Fbutton-number nil))

Perhaps bind the command to a button on the buttonboard, perhaps one each for button 1 and button 3. For example, the 1 and 3 on the numeric keypad might be "KP_End" and "KP_Page_Down".

; Bindings for activating the pointer buttons.
(stumpwm:define-key stumpwm:*top-map*
(stumpwm:kbd "KP_End") "activate-pointer 1")
(stumpwm:define-key stumpwm:*top-map*
(stumpwm:kbd "KP_Page_Down") "activate-pointer 3")

One way to find the names of buttonboard buttons is with "describe-key" in StumpWM, available by default as Control-t h k (New prefix for Help). It prompts with "Describe Key: " and waits for a button to be pressed. Then it reveals the names of the pressed button or sequence of buttons, and the command assigned to it, when any.

Consider activating buttons for a motionbox without jostling it, for when the Xserver cursor is already in the perfect location.

# Alternative for drag'n drop.

A dragon would probably drop what a bird typically drops, as they both have a cloaca, but likely a bit more biohazardous for anyone underneath it. Similarly, accidentally letting go of the button on a motionbox while trying to reposition the cursor might be disasterous, or at least lead to extra work to undo the accident.

The Xserver keeps track of whether a "pointer button" has been pressed, as well as any pressed modifer buttons on the buttonboard intended for that pointer button. As such, it is possible to toggle a button press and a button release individually with the same command bound to a single button on the buttonboard instead.

The Common Lisp X Interface function xlib:query-pointer (CLX 13.5 Pointer Position) reveals what pointer buttons are pressed, by means of the fifth element it returns.

(multiple-value-call 'list

For example, when button 1 is pressed, the result from it is 256, because it is actually the binary mask: 00000001 00000000. The first part (from right to left, just like decimal numbers) indicates the modifer buttons pressed on the buttonboard, with zero meaning nothing pressed. While 2^8 is 256 (t.i. 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2), the eight bits include zero, therefore the first byte is 0–255. A ninth bit is required to begin the next range for 256–511 (instead of 512 for 2^9), which is why the ninth bit is 1 and represents 256.

A decimal number can be used as a mask, which is why the results of xlib:query-pointer returns "256". The binary "1 00000000" is merely a different way of writing the number, rather than a different number. Specifically, in Common Lisp #b100000000 means that is a binary number, which is 1 with eight zeros, the aforementioned "256".

The Xserver seems to track only five pointer buttons, so only the first five bits are used of the second 8-bit byte. That means when there are five buttons on a motionbox and all are pressed (and held), and with no modifier buttons pressed, then the Xserver would return the number known in binary as: 00011111 00000000.

One way to programmatically determine from the bits of such a number which button is pressed is with Common Lisp logic functions (CLHS 12.2 The Numbers Dictionary). For example, logand can compare each bit from two numbers and return a new number. Only the bits for the positions that are 1 in both numbers will be 1 in the new number, otherwise a bit will be zero. Order of the numbers for logand is of no matter because it is only a comparison.

   00011111  -  all five buttons are pressed
   00000100  -  mask representing button 3
   00000100  -  this figured out button 3 is pressed

   00000001  -  only button 1 is pressed
   00000100  -  mask representing button 3
   00000000  -  this figured out button 3 is not pressed

A number can be manipulated like a mask by using "arithmetic shift" to shift the bits to the left or right, by means of the function ash. That means "00000001" (binary for 2) shifted by 3 becomes "00001000" (binary for 8), because a positive shift is leftwards. In other words: 1 * 2^3.

 (ash 1 3)
   => 8

Since buttons 1–5 are positions 1–5 in the 8-bit byte, then the mask for a button can be made by shifting a "1" until it is in the same position. For exmaple, "00000001" to "00000100" for button 3 would be a shift of 2, which is one less than the button number.

 (setf button 3)
 (ash 1 (- button 1))
   => 4

Therefore, a command can be written to inform the Xserver a pointer button has been pressed, and the same command can be used for releasing the pointer button by confirming the button with the mask the Xserver returns when the pointer is queried.

Toggle primary button for "press" or "release", f.e. text selection, drag'n drop without accidental drop, or anything else distinguishing a button press from a button release event.

# Alternative for pointer placement.

The Common Lisp X Interface function xlib:warp-pointer (CLX 13.5 Pointer Position) when given an Xwindow and coordinates will place the pointer at those coordinates within the area of that Xwindow.

Coordinates of the current position of the pointer can be retrieved with a couple of functions. The function xlib:pointer-position (CLX 13.5) when given a specified Xwindow returns the coordinates of the pointer (and some more data). Alternatively, the function xlib:global-pointer-position (CLX 13.5) when given a display (like stumpwm:*display*) returns the coordinates of the pointer and the root window.

These functions make use of the Common Lisp peculiarity (contrary to other Lisps) of "returning multiple values", t.i. returning a series instead of a list. Only the "primary value" gets noticed unless the Common Lisp special operator multiple-value-call (CLHS 5.3 The data and control flow dictionary) or a similar "multiple-value-" macro is used for accessing all the "returned" values, f.e. as an actual list.

(multiple-value-call 'list

#Efficient pointer jumping for any grid of options.

Experience with the pointer a selection-based interface from a consistent grid layout of commands or options, often presented as icons.

    ____  ____  ____  ____
   |    ||    ||    ||    |
   |    || *  ||    ||    |

Start with the pointer placed within the region of one of the options. Displace the pointer either leftward or rightward approximately the same distance as the width of the columns, or either upward or downward appoximately the same distance as the height of the rows.

    ____  ____  ____  ____
   |    ||    ||    ||    |
   | .  || .  || *  || .  |

The xlib:warp-pointer-relative (CLX) displaces the pointer from its current coordinates. It requires a display like stumpwm:*display*, then the offset for the x-axis and the offset for the y-axis.

Eval: (xlib:global-pointer-position stumpwm:*display*)
#<XLIB:WINDOW :0 123>
Eval: (xlib:warp-pointer-relative stumpwm:*display* -64 0)
Eval: (xlib:global-pointer-position stumpwm:*display*)
#<XLIB:WINDOW :0 123>
Eval: jump.offset
The variable JUMP.OFFSET is unbound.Backtrace...
Eval: (setf jump.offset 64)
Eval: (xlib:warp-pointer-relative *display* jump.offset 0)
Eval: (xlib:global-pointer-position *display*)
#<XLIB:WINDOW :0 123>

Consider defining an interactive keymap (Custom interactive keymaps) with a button for displacing the pointer each direction, perhaps i-j-k-l for up-left-down-right. Consider including buttons for pointer activation (Alternative for pointer activation), perhaps "h" for the primary button and ";" for secondary button.

Consider buttons for drag-n-drop when rearranging a grid of items is possible, perhaps "u" for primary button press and "m" for primary button release.

# Mathemagical Xserver cursor placement.

Much like split-view management, the Xserver cursor can be placed anywhere within the bounds of a screen by halving it. Begin in the center of a screen, then split it (left, right, top, or bottom) and center the cursor within one of the halves.

Xserver cursor placement by mathemagically halving the screen, rather than arbitrary pointer motion. That is, no more need to use the force of dramatic physical gestures to move anything. Basic center, left, right, up, and down for positioning quickly, or go back to previous point or the screen center.

Includes pointer activation, and keybindings (for numeric pad), and inspiration...and a "Content outline" for the copious documentation. It is all quite simple, really; the fluff is in the doc rather than the code.

Or, recenter the Xserver cursor at any halving point and it becomes the beginning point. Going back stops at that halving point. Returning to the beginning returns to that recenter point, then returning once more makes the screen center as the beginning point once again.

# Mathemagical pointer and cursor placement.

A single destination:

          y axis
 x axis --+--------------------------------
          | origin       up
          |              |
          |              |    # destination
          |              |
          | left --------+-------- right
          |        point |
          |              |
          |              |
          |             down

Extending lines from the point isolates the destination within a quadrant and reveals the pointer trajectories for intersecting with the destination. Limiting the length of the lines to the width and height of the narrowed region reveals the current precision and the progress.

Many potential destinations:

          y axis
 x axis --+---------------------------------------
          | origin           up
          |                  |
          |                  |
          |                  | destinations
          | left ------------+--#--#--#--#-- right
          |            point |
          |                  |
          |                  |
          |                 down

Multiple potential destinations might be axially aligned, f.e. a menu of options or a toolbar of outlined regions. Placing the pointer first along their axial alignment frees the other axis for selecting any of the items. Another option can be chosen by backtracking a little rather than starting over at the center of the screen.

The pointer has four parts that imply the crossing of a horizontal line with a vertical line. A gap for the implied intersection also provides the visual clearance needed for the Xserver cursor when activating the pointer buttons.

Other programs continue controlling the appearance of the Xserver cursor within their views without interference from the halving pointer.

Pointer placement by mathemagically halving the screen, rather than arbitrary pointer motion includes buttonboard bindings (for numeric pad) for multidirectional placement, and complementary commands for activation of the motionbox pointer.

Consider recentering the pointer and Xserver cursor at any halving point and it becomes the beginning point. Going back stops at that halving point. Returning to the beginning returns to that recenter point, then returning once more makes the screen center as the beginning point once again.

Either way, the pointer-halving-show command conveniently returns the cursor that has been moved (f.e. by a motionbox) back to the pointer position, and pointer-halving-hide hides the pointer without hiding the Xserver cursor. Or, consider combining the commands into pointer-halving-reveal-toggle for toggling revealing and hiding of the pointer.

# Make a point, collect them all, restore them later.

Convert a pointer interface into a selection interface. First, move the Xserver cursor by whatever means available, then mark the location for returning the cursor to it later. Each point is then available as next or prior. Eliminate traversal of a vast void, and never miss a point.

With the convenience commands points-write and points-read, write a list of marked points to a document, then later read and apply that list of points to restore them for use again. Perhaps collect a group of preferred points for a specific program, then swap them for a group of points from another document for another program.

Convert "drag and drop" into "select and put" by adding pointer button activation commands for toggling the press or release of the primary pointer button from the buttonboard.

The hot spot for the Xserver cursor must have clearance when activating a pointer button. A point is drawn as a white perimeter of a square with a black mask, made from four Xwindows.

    ______        _   __   _
   |  __  |      | | |__| | |
   | |  | |  ==  | |      | |
   | |__| |      | |  __  | |
   |______|      |_| |__| |_|

The left and right sides each have a black background, and a subwindow with a black background and a white border as thick as the line for the square perimeter.

For example, the left side (though taller than this):

    window              -->   cropped
    ______                    ______
   |  ____|__                |  ____|<-mask
   | |       |               | |    |
   |b| w _   |               |b| w _|<-perimeter
   |l| h| |  |               |l| h| |
   |a| i| |  |               |a| i| |<-black mask
   |c| t|_|  |               |c| t|_|
   |k| e     |               |k| e  |
   | |_______|subwindow      | |____|
   |______|                  |______|

The top and bottom sides each have a black background, and a subwindow with a white background as wide as the sides and as tall as the perimeter height.

    top or bottom
   |____________|<-black mask
   |subwindow   |<-white perimeter
   |____________|<-black mask

# generational and archæological loss of the computer medium

Writing and reading is the basis of the computer medium. Freedom of expression, t.i. the result of a person taking on the responsibility of speaking for itself, is what has been curiously missing with the commodity computers sold to the everyday person. Choice is often the only opportunity given to the purchaser of a computer, choosing amongst decisions already made by the software developers.

The skill of writing and reading has been impressed upon as many people as possible, and has become an expected means of learning and communicating. However, the computer medium is sold as a means of looking and pointing at options thought of by somebody else, failing at integrating with the flow of thoughts and actions of the everyday person implementing the computer medium. Paying money for a computer and then having applications do what somebody else wanted to do can only be a novelty, merely entertaining a person whose desires were never asked.

A computer application, a type of software, is an example of grouping basic commands for a specific task. Obviously, that is very useful for the person who groups them, and less so for a person when they are grouped by someone else.

Sometimes a single command is a group of other commands rather than emerging from new computer programming. A list of commands can be saved for later recall as a single command, f.e. by repeating the sequence of commands the person has just done.

Arbitrary actions with a pointer are prone to misinterpretation when part of automating repetitious activities. A shared command whose composition can never be explored, whose list of subcommands is forbidden from discovery, is an insincere gift that will fail to support the everyday person to correct it, simplify it, or adapt it for personal comfort.

Ultimately, personal expression is supported by writing and reading, impeded by insincere sharing, and essentially neutralized by having only choices. Sharing an approach inspires and supports the emergence of new approaches, with dissimilarity possible though unrequired.

The computer medium is inferior (f.e. when compared with pen and paper) for promoting self-education and cultural growth when it is distributed as an unexplorable trade secret providing a kiosk of choices rather than unrestrictedly adaptable by the everyday person for each moment of life.

# The everyday person should never have a PC

A personal computer (PC) is a computer for one person in an office at work rather than a shared computer like a data terminal. A company provides the PC for use by the employee in the office, and the "home PC" for working from home. The everyday person was never supposed to have a home work computer.

Curiously, many operating systems provide no place for typing a command from personal recall or personal notes. Buttonboards usually have no dedicated "prompt" or "command" button for immediately specifying commands.

Instead, an abbreviation or pseudonym for a command is typed, though without any place to type it. That typically involves holding one or more buttons, a randomly logical concoction at the bottom of the buttonboard.

With no dedicated buttons on the buttonboard for all commands and nothing displayed on the screen when typing the abbreviations, there is only hope of what command will be evoked.

Conventionally, pre-categorized menus gradually reveal sublistings of commands. The aforementioned invisible typing of their abbreviations have been the only means for bypassing the interminable spelunking of those labyrinthine menus.

Silly, but that is how a home personal computer has been since forever it seems. But then again, it is work.

A personal computer can be repurposed into a personalizable computer. The personalizable computer can then be an impromptu interface for work computers by means of VNC or remote desktop programs. Less work, more fitting, and potentially no computer programming skills needed.

# Recipes and pseudocode

An approach is a recipe or pseudocode, and its application is the result.

A recipe declares an intent by means of a list of ingredients and events that have been effective for producing a desired result. An application is the result of the recipe, a final presentation either palatable or inedible.

A computer application is typically an approach applied by someone else for the results desired by that other person. With a computer, an application of an approach is invariable, but pseudocode is by definition a recipe and therefore an adaptable approach. The pseudocode is the gist and intentions, the springboard for a variety of forms, thereby distinct from any specific attempt.

Life is variable. The predefined results of applications are inapplicable to the ever changing flow of events. On the other hand, an approach is guidance for transitioning through a moment, retaining opportunity for adaptation with each jump.

# Intention is distinct from documentation

Too often computer programs have been said to be lacking documentation, but it is also without expression of intent. Without intent and motivation, there is no pursuit, there is no follow through.

Without well thought out desires recorded, results like a set of computer program instructions are without a foundation. Afterwards, documentation of the code that emerges is the recording of decisions for using certain computer instructions, experiences with alternatives, or suggestions of potential alternatives.

A computer programming language is merely a set of symbols or codewords. A computer is simply a machine, a piece of hardware, there is no possible communication with it. Instead, such a "language" is merely a writing system for a person briefly recording a set of instructions. Computer programming without documentation is as informative as a quote taken out of context.

Ingredients are fabricated within the computer memory, or perhaps parts of the computer hardware are activated with it. Even then, the phrases and terms need to be interpreted as a specified sequence of toggle switches within the circuitry of that machine, typically a barebones coding with only two letters in its alphabet and no phonemes because it is never spoken.

In other words, the computer is just a tool chosen for applying an appoach. Punctuation symbols and code words of computer programming record mere gesticulations of the person applying the approach. Therefore, the approach or purpose is inherently underivable from the computer coding, as it is no more than the pattern on a wall of toggled switches.

An approach must be recorded before or as it is applied if it is ever to be known by anyone else, as many archeologists have lamented. Minimizing it by shedding its context of intent and motivation deprives everyone of its meaning, even the later self of the person applying it.

To reiterate, there is no communication possible with a "computer language", for it is only a writing system intended for toggling switches for a result rather than sharing an understanding with another person. A computer program is merely one adaptation of an approach, one choreographed dance for a feeling, forever unrevealing of its own inception.

# An operatable system

A computer is a medium for writing and reading, with the writing reduced to mere presses of labeled buttons for each letter of an alphabet. There is no other skill needed for operating a computer, though there are sometimes other means besides a buttonboard.

A computer is operatable, and automatable, when it is capable of restoring what has been recorded within its medium. That is, a computer recording the actions done with it in the moment and then repeating those actions upon request is being operated.

A system of programs operating on their own, especially when unmodifiable, is an "operating system". Somebody else's program is somebody else's operation of a computer, recorded from some other moment for that other person.

As a computer program is a proxy for the person who created it, vetting a computer program is the same as trusting the person who wrote it, perhaps a complete stranger. A computer virus is merely a computer program. A system readily operating on its own, t.i. an operating system, is operating for the interests and intentions of the people who wrote the programs.

In contrast, an "operatable system" does nothing until it is operated, so known programs can be the only programs ever activated or automated, per the decisions made by the person operating the computer.

There is no denying the various computer mediums are archeologically unsound. That makes it all the more important for using the computer medium as freely as possible during this transition beyond the computer medium itself for more sustainable, sharable, and perusable recording mediums. The medium of pen and paper (as an example of the latter) preceded the computer medium, and is destined to continue beyond the computer medium during the search for other millenially persisting recording mediums like pen and paper, clay tablets, and stone structures.

The unadaptable predetermined decisions of the operating-system/application paradigm is worthless for the everyday person, who is the core of any people, the core of any culture. This is evident by companies creating applications for their own use, with the employee (an everyday person) making do with what is available while waiting for those applications.

An operating system is non-functioning without its applications, and developing an application is a tangent away from the flow of the moment. Without documentation, there is no hope of adapting someone else's program for the current moment. There is only choice of the decisions made by someone else, without opportunity for freedom of expression by the person choosing.

A core characteristic of the computer medium is that of immediate and exact duplication of any of its recordings, thereby the freedom for trial and dismissal without loss or corruption of the original version. That is the opportunity of self improvement with the freedom of saving and reviewing inspirations and influences, and sharing those with the community for discussion and accelerating cultural development.

# Design is a collection of foreign decisions

Voting is choosing amongst a set of pre-made decisions. A decision is inherently presumed acceptable, regardless of whether it is desirable. Choosing from someone else's menu is choosing from someone else's comfort, perhaps a selection of someone else's abilities. A vote or a choice is at most the wiggling of a toe tag, nothing like personal expression as there is no opportunity for a personal decision.

Design is a set of decisions. Somebody else's design is somebody else's decisions. Ultimately, a design is a past, foreign to the present, an opportunity for reflection and release. The adaptation of a set of decisions is the conversion of it into a new approach, perhaps a setup for a eventual spin-off or even a prequel.

# Computer displays: punchcard or GUI

Punchcard is a recording medium readable by computers and people, a type of memory card, t.i. a memcard. A punchcard can be a piece of cardboard with holes made from a holepunch tool, by either a person or a machine. The holes and the lack thereof are arranged along rows and columns of a grid, and can be detected by either machinary or a person feeling a card, or by a person visually perceiving the arrangement of the holes in a card.

A "graphical user interface" (GUI) is an oblique phrase for any object with drawings on it, essentially for only visual interpretation rather than physical or aural. For example, a sheet of paper, or a sheet of glass, or a grid of lights. Text and other shapes are drawn with lines or with dots, perhaps by coloring each square of a grid.

Obviously, shape is visibly noticeable only when there are at least two distinctive colors; corollarily, there are no distinctions with only one color. Text and other shapes can be drawn with only two colors available, commonly referred to as a foreground color for the most important areas and a background color for less important areas. Additional colors allow for more distinctions, thereby more variety of lines and dots for text and other shapes. Notably, an extraneous use of distinction is distracting or muddling.

A drawing, t.i. a graphical recording, using more than two colors on a grid bound by having only a single color per square (t.i. a dot) can record a greater variety than a punchcard using only one hole shape. Similarly, more than one physically distinguishable hole shape would increase the variety for a punchcard.

Notably, the raised dots of braille pressed into paper are the inverse of a hole, and provides such a variety potentially detectable by machines, too. Furthermore, the eight-dot version of braille is equivalent to the eight-bits of a byte, thereby suggesting bytes might be readily perceived visually and physically. The million symbols or characters of Unicode is one step away from that, each represented by one or more bytes, f.e. with the UTF-8 or UTF-32 formats.

A touchscreen is a transparent overlay for a graphical display, such as on top of a sheet of paper or on top of a grid of lights. The drawings of text and shapes, or the lack thereof, beneath the screen are coordinated with the same areas of the transparent screen overlaying them. The transparent screen detects physical touch, and those touches are related with the areas on the graphical display. While that physical action with the overlay is imitative of recording information on a punchcard, an unshapable graphical display remains unreadable physically.

HyperText Markup Language (HTML)
markup a CSS stylesheet
basic PDF 1.4
approaches for documenting binary files
file transfer, find, and grep
ssh key generation and use
notes about emacs: essentials and elaborate
installing emacs
email in emacs
ImageMagick command-line options for convert and mogrify (or magick as of 7.x)
Examples of ImageMagick Usage (6.x)