Make pattern mapping chained

This commit is contained in:
Tangent Wantwight 2023-07-29 16:26:41 -04:00
parent e61485012e
commit 36f78982e6
2 changed files with 40 additions and 51 deletions

View file

@ -6,7 +6,7 @@
*/
var Notcl = (() => {
const { AtLeast, Choose, End, Map, Regex, Sequence, Use } = Peg;
const { AtLeast, Choose, End, Regex, Sequence, Use } = Peg;
const InterCommandWhitespace = Regex(/\s+/y);
@ -16,52 +16,38 @@ var Notcl = (() => {
const PreWordWhitespace = Regex(/[^\S\n;]*/y);
const BasicWord = Map(Regex(/[^\s;]+/y), ([word]) => ({
text: word,
}));
const BasicWord = Regex(/[^\s;]+/y).map(([word]) => ({ text: word }));
// WIP, need to be able to escape braces correctly
// WIP, error if anything after closing brace
/** @type {Peg.Pattern<string>} */
const Brace = Map(
Sequence(
Regex(/\{/y),
AtLeast(
0,
Choose(
Map(
Use(() => Brace),
(text) => `{${text}}`
),
Map(Regex(/[^{}]+/y), ([text]) => text)
)
),
Regex(/\}/y)
),
([_left, fragments, _right]) => fragments.join("")
);
const Word = Map(
Sequence(
PreWordWhitespace,
const Brace = Sequence(
Regex(/\{/y),
AtLeast(
0,
Choose(
Map(Brace, (text) => ({
text,
})),
BasicWord
Use(() => Brace).map((text) => `{${text}}`),
Regex(/[^{}]+/y).map(([text]) => text)
)
),
([_, word]) => word
);
Regex(/\}/y)
).map(([_left, fragments, _right]) => fragments.join(""));
const Word = Sequence(
PreWordWhitespace,
Choose(
Brace.map((text) => ({ text })),
BasicWord
)
).map(([_, word]) => word);
const CommandTerminator = Sequence(
PreWordWhitespace,
Choose(/** @type {Peg.Pattern<unknown>} */ (Regex(/[\n;]/y)), End)
);
const Command = Map(
Sequence(PreCommand, AtLeast(0, Word), CommandTerminator),
const Command = Sequence(PreCommand, AtLeast(0, Word), CommandTerminator).map(
([_padding, words, _end]) => words
);

39
peg.js
View file

@ -4,9 +4,19 @@
* If it matches successfully, it returns some captured value, and the index following the match.
*
* @template T
* @typedef {{
* (source: string, index: number): ([T, number] | null)
* }} Peg.Pattern
* @callback Peg.PatternCall
* @param {string} source - the string being parsed
* @param {number} index - the index in the string to begin matching from
* @returns {[T, number] | null} - if successful, the captured value & the index to start parsing following symbols from. Else, null.
*/
/**
* @template T
* @typedef {object} Peg.PatternExt
* @property {<U>(map: (value: T) => U) => Peg.Pattern<U>} map Creates a pattern that wraps another pattern, transforming the returned value on a match
*/
/**
* @template T
* @typedef {Peg.PatternCall<T> & Peg.PatternExt<T>} Peg.Pattern
*/
var Peg = window.Peg ?? {};
@ -18,6 +28,13 @@ var Peg = window.Peg ?? {};
* @returns {Peg.Pattern<T>}
*/
Peg.WrapPattern = function (pattern) {
/** @type {Peg.Pattern<T>} */ (pattern).map = function (map) {
return Peg.WrapPattern(function (source, index) {
const match = pattern(source, index);
return match ? [map(match[0]), match[1]] : null;
});
};
return /** @type {Peg.Pattern<T>} */ (pattern);
};
@ -36,20 +53,6 @@ Peg.Use = function (getPattern) {
});
};
/**
* Creates a pattern that wraps another pattern, transforming the returned value on a match
* @template T, U
* @param {Peg.Pattern<T>} pattern
* @param {(value: T)=> U} map
* @return {Peg.Pattern<U>}
*/
Peg.Map = function (pattern, map) {
return Peg.WrapPattern(function (source, index) {
const match = pattern(source, index);
return match ? [map(match[0]), match[1]] : null;
});
};
/**
* Creates a pattern matching a regex & returning any captures. The regex needs to be sticky (using the //y modifier)
* @param {RegExp} regex
@ -108,7 +111,7 @@ Peg.Sequence = function (...patterns) {
/**
* Creates a pattern that matches consecutive runs of the given pattern, returning an array of all captures.
*
* The match only succeeds if the run is at least {min} instances long.
* The match only succeeds if the run is at least {@link min} instances long.
*
* If the given pattern does not consume input, the matching will be terminated to prevent an eternal loop.
*