prototype-3x5/notcl.js

102 lines
2.3 KiB
JavaScript

/**
* @typedef {Notcl.Command[]} Notcl.Script
* @typedef {Notcl.Word[]} Notcl.Command
* @typedef {object} Notcl.Word
* @property {string} text
*/
var Notcl = (() => {
const InterCommandWhitespace = Peg.Regex(/\s+/y);
const Comment = Peg.Regex(/#.*\n/y);
const PreCommand = Peg.AtLeast(
0,
Peg.Choose(InterCommandWhitespace, Comment)
);
const PreWordWhitespace = Peg.Regex(/[^\S\n;]*/y);
const BasicWord = Peg.Map(Peg.Regex(/[^\s;]+/y), ([word]) => ({
text: word,
}));
// WIP, need to be able to escape braces correctly
// WIP, error if anything after closing brace
const BracePattern = Peg.Map(
Peg.Sequence(
Peg.Regex(/\{/y),
Peg.AtLeast(
0,
Peg.Choose(
Peg.Map(Brace, (text) => `{${text}}`),
Peg.Map(Peg.Regex(/[^{}]+/y), ([text]) => text)
)
),
Peg.Regex(/\}/y)
),
([_left, fragments, _right]) => fragments.join("")
);
/**
* @type {Peg.Pattern<string>}
*/
function Brace(source, index) {
// Thunk to allow Brace to recurse
return BracePattern(source, index);
}
const Word = Peg.Map(
Peg.Sequence(
PreWordWhitespace,
Peg.Choose(
Peg.Map(BracePattern, (text) => ({
text,
})),
BasicWord
)
),
([_, word]) => word
);
const CommandTerminator = Peg.Sequence(
PreWordWhitespace,
Peg.Choose(
/** @type {Peg.Pattern<unknown>} */ (Peg.Regex(/[\n;]/y)),
Peg.End
)
);
const Command = Peg.Map(
Peg.Sequence(PreCommand, Peg.AtLeast(0, Word), CommandTerminator),
([_padding, words, _end]) => words
);
return {
/**
* Parse out a Notcl script into an easier-to-interpret representation.
* No script is actually executed yet.
*
* @param {string} code
* @returns Script
*/
parse(code) {
/* Preprocess */
// fold line endings
code = code.replace(/(?<!\\)((\\\\)*)\\\n/g, "$1");
function nextCommand() {
const [words, nextIndex] = Command(code, 0) ?? [[], 0];
code = code.substring(nextIndex);
return words;
}
/* Loop through commands, with safety check */
const script = /** @type {Notcl.Command[]} */ ([]);
for (let i = 0; i < 1000 && code != ""; i++) {
script.push(nextCommand());
}
return script;
},
};
})();