yoob.js
=======
*Version 0.13. Everything subject to change.*
*For version history, see the file [HISTORY.markdown](HISTORY.markdown).*
yoob.js started out as the HTML5 counterpart to [yoob][], but has since
grown to include several generally-useful facilities for making animated
and interactive HTML5 pages.
[yoob]: http://catseye.tc/node/yoob
Like yoob, yoob.js:
* provides a set of components for implementing visual interpreters for
esoteric programming languages (esolangs).
* is written amateurishly.
* has an API that is not particularly good, finalized, or stable.
Unlike yoob, yoob.js:
* is written in Javascript which assumes HTML5 capabilities in the browser
(mainly support for the `<canvas>` element.)
* does not provide a single canonical overarching framework which "knows"
how to interpret and display and run an esolang implementation. Instead,
more fitting with the dynamic approach of the Javascript language, yoob.js
provides the constituent parts, and it's up to the developer to string
them together into an esolang interpreter (or whatever else) and to lay it
out on a web page.
* is not limited to providing support for esolang interpreters; it might
be better described as a set of components for implementing esolangs "and
other bizarre things".
* does not support unbounded integer values (yet; see "Planned", below).
* provides components which are meant to be used as starting points for
further modification. (It's all public domain, so mangle it up!) For
example, `yoob.SexpParser` is meant to be used as an example or basis for
a specific grammar of your choice.
Other things you should know about yoob.js are that it:
* requires features from HTML5 and related "modern" web standards. With
the exception of a few simple "shims" for a few critical things, it does
not try to do any feature detection or polyfilling. If it doesn't work
in your browser, it doesn't work in your browser. Try another browser.
* does not rely on jQuery or any other front-end web framework.
* does not come minified or agglomerated or anything. I mean, this isn't
production web development, we're not trying to optimize page load time
here, we just want to run us some esolangs, right? You're free to do
this yourself. May we suggest `cat yoob/*.js > yoob.js`? (Note: there
may one day be a small script to do this sort of thing for you, more
intelligently, respecting dependencies and whatnot. Especially if you
write it and send a pull request.)
Used in
-------
yoob.js is currently used in the HTML5 implementations of:
* [Gemooy][]
* [Wunnel][]
* [Etcha][]
* [noit o' mnain worb][]
* [Super Wumpus Land][]
* [REDGREEN][]
* [Circute][]
* [Braktif][]
* [Jaccia][] and Jacciata
* [Cyclobots][] and many other [HTML5-Gewgaws][]
[Gemooy]: http://catseye.tc/node/Gemooy
[Wunnel]: http://catseye.tc/node/Wunnel
[Etcha]: http://catseye.tc/node/Etcha
[Javascript BigInteger]: https://github.com/silentmatt/javascript-biginteger
[noit o' mnain worb]: http://catseye.tc/node/noit_o%27_mnain_worb.html
[Super Wumpus Land]: http://catseye.tc/node/Super_Wumpus_Land
[REDGREEN]: http://catseye.tc/node/REDGREEN
[Circute]: http://catseye.tc/node/Circute
[Braktif]: http://catseye.tc/node/Braktif
[Jaccia]: http://catseye.tc/node/Jaccia
[Cyclobots]: http://catseye.tc/node/Cyclobots
[HTML5-Gewgaws]: https://github.com/catseye/HTML5-Gewgaws
API
---
Each yoob.js class is defined in some `.js` file, and each `.js` file
inserts the class\[es\] it defines into the `yoob` namespace (which it will
create as a new, empty, global namespace if it has not already been defined.)
The classes are currently:
* `yoob.Playfield`, in `yoob/playfield.js`
A two-dimensional Cartesian grid of values which dynamically expands as
needed. Objects of this class are suitable for representing programs in
two-dimensional esolangs such as Befunge, as well as cellular automata,
and suitable for use as a backing store for a text-terminal simulator.
* `yoob.Cursor`, in `yoob/cursor.js`
An object representing position and direction in some space, which may
be one-dimensional (typically a `yoob.Tape`, where it serves as a tape
head) or two-dimensional Cartesian space (typically a `yoob.Playfield`).
The direction aspect need not not necessarily be used.
* `yoob.PlayfieldCanvasView`, in `yoob/playfield-canvas-view.js`
A view (in the MVC sense) which associates a `yoob.Playfield` with a
`<canvas>` element in the DOM. The playfield will be depicted on the
canvas, which can also dynamically expand as needed.
* `yoob.PlayfieldHTMLView`, in `yoob/playfield-html-view.js`
A view (in the MVC sense) which associates a `yoob.Playfield` with any
element which supports `innerHTML`, although typically a `<pre>` element.
Compared to the canvas view, this view will allow text to be rendered
more nicely in some browsers, be selected for copying/pasting in the
browser, and so forth.
* `yoob.SourceHTMLView`, in `yoob/source-html-view.js`
A view (in the MVC sense) which associates a program text with any
element which supports `innerHTML`, although typically a `<pre>` element.
This supports displaying cursors on a linear program text.
* `yoob.TextTerminal`, in `yoob/text-terminal.js`
A crude simulation of a text-based addressable console, including some
functions (which need not be used) which understand simple terminal
control sequences, such as LF and backspace. Requires `yoob.Playfield`
and `yoob.Cursor` and, if you actually want to render the terminal in
a browser DOM, `yoob.PlayfieldCanvasView` or a compatible playfield
view class.
* `yoob.LineInputBuffer`, in `yoob/line-input-buffer.js`
A crude simulation of a buffer into which the user can type a line of
text. Typically it is associated with a `yoob.TextTerminal` object, on
which the text is displayed as the user types it.
* `yoob.Tape`, in `yoob/tape.js`
A (theoretically) unbounded tape, like you'd find on a Turing machine.
It can also be used as a push-down, first-in-first-out stack of values,
like you'd find on a push-down automaton.
* `yoob.TapeCanvasView`, in `yoob/tape-canvas-view.js`
and `yoob.TapeHTMLView`, in `yoob/tape-html-view.js`
Like `yoob.PlayfieldCanvasView` and `yoob.PlayfieldHTMLView`,
except for `yoob.Tape`s.
* `yoob.Tree`, in `yoob/tree.js`
A multi-purpose, n-ary tree, with optional node name (String identifier)
and payload (arbitrary value.) Children are indexed by integer, 0-based.
It's meant to serve two main purposes:
* as an AST (Abstract Syntax Tree) for the (initial) intermediate
representation(s) of a program in an interpreter or compiler, in
which case the node name is the node type and the payload is anything
that might be handy, such as what the tree evaluated to; and
* as _terms_, roughly as defined in the science of term rewriting. In
this case the node name is the "constructor" and the payload is
probably not used. For this purpose, the `tree.js` module should
eventually include facilities for matching and unification.
Trees, with only two children, could also be used as lists a la Lisp. In
this case the node name and payload would both go unused.
* `yoob.Scanner`, in `yoob/scanner.js`
A simple, inefficient lexical analyzer, parameterized with a table of
regexps. Can also serve as a starting point for writing your own, less
simple, inefficient lexical analyzer.
* `yoob.SexpParser`, in `yoob/sexp-parser.js`
A simple recursive-descent parser which parses S-expressions. Uses
`yoob.Scanner` to analyze the input string and `yoob.AST` to create the
parsed version. Can also serve as a starting point for writing your own
recursive-descent parser for some other, more complex language.
* `yoob.Controller`, in `yoob/controller.js`
A controller for animating the evolution and animation of a state
(such as an esolang program state or a cellular automaton configuration).
Can be hooked up to DOM elements in the UI (typically buttons.)
* `yoob.SourceManager`, in `yoob/source-manager.js`
An object for managing the editing and registering (generally, to a
`yoob.Controller`) the textual source of a program or configuration.
* `yoob.PresetManager`, in `yoob/preset-manager.js`
An object for managing a set of "presets" — which, for an esolang,
might be example programs; for an emulator, might be ROM images;
for a control panel, may be pre-selected combinations of settings;
and so forth. May be used to populate the source of a `yoob.SourceManager`
and/or a `yoob.Controller`,
* `yoob.Sprite` and `yoob.SpriteManager`, in `yoob/sprite-manager.js`
A set of classes for (somewhat crudely) managing independent things which
can be placed, moved, be clicked, and be dragged around a canvas.
* `yoob.Turtle`, in `yoob/turtle.js`
For Turtle Graphics. This is a "model" rather than a "view"; movement
of the turtle generates a `yoob.PathList` (see below) which can then be
drawn on a canvas (or not.)
* `yoob.Path` and `yoob.PathList`, in `yoob/path.js`
A `Path` is an abstraction of a path (a list of connected, two-dimensional
points.) Think of it as a model that also contains a convenient default
view (i.e., it knows how to draw itself into a 2d drawing context.) A
`PathList` is an ordered list of paths along with some convenience methods.
* `yoob.FullScreenDetector`, in `yoob/full-screen-detector.js`
A shim (of sorts) which detects when the user has toggled their browser's
full-screen mode (usually but not necessarily by pressing the F11 key) and
fires an 'onchange' event, in which you can resize DOM elements of your
choosing to suit the (non-)full-screen display (or whatever else you wish.)
Note that this is unrelated to the idea of *programatically* asking the
browser to go into full-screen mode. That isn't supported (but if you do
do that by some other means, the detector should still detect it.)
* `yoob.Joystick`, in `yoob/joystick.js`
Emulates a joystick, with some finesse. Be default, this is with the
cursor keys as directional control, and either control key as the fire
button. However, this is configurable.
* `yoob.Chargen`, in `yoob/chargen.js`
An object for producing bitmapped-character-like displays, such as those
found on 8-bit retrocomputers. A monochromatic image, with the character
patterns in a regular grid, must be supplied. Chromatic versions of the
character patterns, in each of the given colours, will be automatically
created. The character data may also be modified programatically.
* `yoob.Animation`, in `yoob/animation.js`
An object which manages animations. It is given an object to operate on,
and can be initialized in one of two modes. The `quantum` mode calls the
given object's `draw()` method on each animation frame, and calls the
object's `update()` method as necessary to ensure that `update()` is called
once every given number of milliseconds (default being 1/60th of a second.)
The `proportional` mode calls the object's `draw()` method on each animation
frame, passing to it the amount of time that has elapsed (in milliseconds)
since the last time it was called.
This object uses the `requestAnimationFrame` API to conduct the animation,
or falls back on its included `setInterval`-based shim in browsers which
don't support `requestAnimationFrame` (or support it only under "their"
name.)
This object is a replacement for the deprecated `*AnimationFrame` functions
which appeared in an earlier version.
* `yoob.Varier`, in `yoob/varier.js`
A small wrapper on top of `yoob.Animation` which varies a variable from
one value to another, automatically stopping the animation when the final
value has been reached.
* `yoob.CanvasResizer`, in `yoob/canvas-resizer.js`
An object which attempts to intelligently resize a canvas element, to make
it fit inside the browser window at all times, resizing it or making it
disappear if necessary, and retaining a maximum size or aspect ratio, if
requested.
Plus some functions which aren't classes:
* `yoob.showSplashScreen`, in `yoob/splash-screen.js`
An adapter-type thing which displays a `div` element with some inner HTML
(typically containing a message or logo or such) and a "Proceed" button,
all in place of a given element. When the button is clicked, the `div` is
hidden, the given element is revealed, and a callback is invoked.
The intention is to allow a "splash screen", which may contain a disclaimer
or similar, before the "main stage" is actually displayed and started.
* `yoob.make*`, in `yoob/element-factory.js`
Convenience functions for creating DOM elements. Some of them create
groups of elements that co-operate to provide a functionality in the UI
(e.g. spin controls.)
### Planned ###
* `yoob.Environment`
A scoped associative structure, suitable for implementing a symbol
table or an evaluation context.
* `yoob.Error`
For error handling. Scanning and Parsing should accumulate a
list of these objects before choking and dying. They should be
displayable nicely somehow.
* unbounded integer support
Although yoob.js will likely not ship with an unbounded integer
implementation (unless someone wants to contribute one), certain
classes (Tape, Playfield) should probably, one day, have limited
support for working with objects which conform to a subset of the API
exposed by Matthew Crumley's [Javascript BigInteger][] class, which is
unastonishing.