// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at <https://mozilla.org/MPL/2.0/>.
-import { bind, call, identity, makeCallable } from "./function.js";
import {
+ bind,
+ call,
+ createArrowFunction,
+ createCallableFunction,
+ identity,
+} from "./function.js";
+import {
+ arrayIteratorFunction,
+ stringIteratorFunction,
+} from "./iterable.js";
+import {
+ defineOwnDataProperty,
defineOwnProperties,
getOwnPropertyDescriptors,
- getPrototype,
objectCreate,
+ setPropertyValues,
setPrototype,
} from "./object.js";
-import { ITERATOR, TO_STRING_TAG } from "./value.js";
+import { sameValue, toLength, UNDEFINED } from "./value.js";
const RE = RegExp;
const { prototype: rePrototype } = RE;
* expression with `^(?:` and `)$` if you don’t want nongreedy
* regular expressions to fail when shorter matches are possible.
*/
- constructor(source, name = undefined, constraint = null) {
+ constructor(source, name = UNDEFINED, constraint = null) {
super(
($) => {
if (typeof $ !== "string") {
return defineOwnProperties(
setPrototype(this, matcherPrototype),
{
- lastIndex: {
+ lastIndex: setPropertyValues(objectCreate(null), {
configurable: false,
enumerable: false,
value: 0,
writable: false,
- },
- name: {
- value: name != null
+ }),
+ name: defineOwnDataProperty(
+ objectCreate(null),
+ "value",
+ name != null
? `${name}`
: `Matcher(${call(reToString, regExp, [])})`,
- },
+ ),
},
);
}
}
};
- const matcherConstructor = defineOwnProperties(
+ const matcherConstructor = Object.defineProperties(
class extends RegExp {
constructor(...args) {
return new Matcher(...args);
}
},
{
- name: { value: "Matcher" },
- length: { value: 1 },
+ name: defineOwnDataProperty(
+ Object.create(null),
+ "value",
+ "Matcher",
+ ),
+ length: defineOwnDataProperty(Object.create(null), "value", 1),
},
);
const matcherPrototype = defineOwnProperties(
matcherConstructor.prototype,
getOwnPropertyDescriptors(Matcher.prototype),
- { constructor: { value: matcherConstructor } },
+ {
+ constructor: defineOwnDataProperty(
+ Object.create(null),
+ "value",
+ matcherConstructor,
+ ),
+ },
);
return { Matcher: matcherConstructor };
stringReplaceAll(
`${$}`,
/[A-Z]/gu,
- makeCallable(stringToLowercase),
+ createCallableFunction(stringToLowercase),
),
asciiUppercase: ($) =>
stringReplaceAll(
`${$}`,
/[a-z]/gu,
- makeCallable(stringToUppercase),
+ createCallableFunction(stringToUppercase),
),
};
})();
+/**
+ * Returns −0 if the provided argument is "-0"; returns a number
+ * representing the index if the provided argument is a canonical
+ * numeric index string; otherwise, returns undefined.
+ *
+ * There is no clamping of the numeric index, but note that numbers
+ * above 2^53 − 1 are not safe nor valid integer indices.
+ */
+export const canonicalNumericIndexString = ($) => {
+ if (typeof $ !== "string") {
+ return UNDEFINED;
+ } else if ($ === "-0") {
+ return -0;
+ } else {
+ const n = +$;
+ return $ === `${n}` ? n : UNDEFINED;
+ }
+};
+
export const {
+ /**
+ * Returns an iterator over the codepoints in the string representation
+ * of the provided value according to the algorithm of
+ * `String::[Symbol.iterator]`.
+ */
+ characters,
+
/**
* Returns an iterator over the code units in the string
* representation of the provided value.
* representation of the provided value.
*
* Codepoints which are not valid Unicode scalar values are replaced
- * with U+FFFF.
+ * with U+FFFD.
*/
scalarValues,
-
- /**
- * Returns the result of converting the provided value to a string of
- * scalar values by replacing (unpaired) surrogate values with
- * U+FFFD.
- */
- scalarValueString,
} = (() => {
- const { [ITERATOR]: arrayIterator } = arrayPrototype;
- const arrayIteratorPrototype = Object.getPrototypeOf(
- [][ITERATOR](),
+ const generateCharacters = function* (character) {
+ yield character;
+ };
+ const generateCodeUnits = function* (ucsCharacter) {
+ yield getCodeUnit(ucsCharacter, 0);
+ };
+ const generateCodepoints = function* (character) {
+ const { allowSurrogates } = this;
+ const codepoint = getCodepoint(character, 0);
+ yield allowSurrogates || codepoint <= 0xD7FF || codepoint >= 0xE000
+ ? codepoint
+ : 0xFFFD;
+ };
+
+ const charactersIterator = stringIteratorFunction(
+ generateCharacters,
+ "String Character Iterator",
);
- const { next: arrayIteratorNext } = arrayIteratorPrototype;
- const iteratorPrototype = Object.getPrototypeOf(
- arrayIteratorPrototype,
+ const codeUnitsIterator = arrayIteratorFunction(
+ generateCodeUnits,
+ "String Code Unit Iterator",
);
- const { [ITERATOR]: stringIterator } = stringPrototype;
- const stringIteratorPrototype = Object.getPrototypeOf(
- ""[ITERATOR](),
+ const codepointsIterator = stringIteratorFunction(
+ bind(generateCodepoints, { allowSurrogates: true }, []),
+ "String Codepoint Iterator",
);
- const { next: stringIteratorNext } = stringIteratorPrototype;
-
- /**
- * An iterator object for iterating over code values (either code
- * units or codepoints) in a string.
- *
- * ※ This class is not exposed, although its methods are (through
- * the prototypes of string code value iterator objects).
- */
- const StringCodeValueIterator = class extends identity {
- #allowSurrogates;
- #baseIterator;
-
- /**
- * Constructs a new string code value iterator from the provided
- * base iterator.
- *
- * If the provided base iterator is an array iterator, this is a
- * code unit iterator. If the provided iterator is a string
- * iterator and surrogates are allowed, this is a codepoint
- * iterator. If the provided iterator is a string iterator and
- * surrogates are not allowed, this is a scalar value iterator.
- */
- constructor(baseIterator, allowSurrogates = true) {
- super(objectCreate(stringCodeValueIteratorPrototype));
- this.#allowSurrogates = !!allowSurrogates;
- this.#baseIterator = baseIterator;
- }
-
- /** Provides the next code value in the iterator. */
- next() {
- const baseIterator = this.#baseIterator;
- switch (getPrototype(baseIterator)) {
- case arrayIteratorPrototype: {
- // The base iterator is iterating over U·C·S characters.
- const {
- value: ucsCharacter,
- done,
- } = call(arrayIteratorNext, baseIterator, []);
- return done
- ? { value: undefined, done: true }
- : { value: getCodeUnit(ucsCharacter, 0), done: false };
- }
- case stringIteratorPrototype: {
- // The base iterator is iterating over Unicode characters.
- const {
- value: character,
- done,
- } = call(stringIteratorNext, baseIterator, []);
- if (done) {
- // The base iterator has been exhausted.
- return { value: undefined, done: true };
- } else {
- // The base iterator provided a character; yield the
- // codepoint.
- const codepoint = getCodepoint(character, 0);
- return {
- value: this.#allowSurrogates || codepoint <= 0xD7FF ||
- codepoint >= 0xE000
- ? codepoint
- : 0xFFFD,
- done: false,
- };
- }
- }
- default: {
- // Should not be possible!
- throw new TypeError(
- "Piscēs: Unrecognized base iterator type in %StringCodeValueIterator%.",
- );
- }
- }
- }
- };
-
- const {
- next: stringCodeValueIteratorNext,
- } = StringCodeValueIterator.prototype;
- const stringCodeValueIteratorPrototype = objectCreate(
- iteratorPrototype,
- {
- next: {
- configurable: true,
- enumerable: false,
- value: stringCodeValueIteratorNext,
- writable: true,
- },
- [TO_STRING_TAG]: {
- configurable: true,
- enumerable: false,
- value: "String Code Value Iterator",
- writable: false,
- },
- },
+ const scalarValuesIterator = stringIteratorFunction(
+ bind(generateCodepoints, { allowSurrogates: false }, []),
+ "String Scalar Value Iterator",
);
- const scalarValueIterablePrototype = {
- [ITERATOR]() {
- return {
- next: bind(
- stringCodeValueIteratorNext,
- new StringCodeValueIterator(
- call(stringIterator, this.source, []),
- false,
- ),
- [],
- ),
- };
- },
- };
return {
- codeUnits: ($) =>
- new StringCodeValueIterator(call(arrayIterator, `${$}`, [])),
- codepoints: ($) =>
- new StringCodeValueIterator(
- call(stringIterator, `${$}`, []),
- true,
- ),
- scalarValues: ($) =>
- new StringCodeValueIterator(
- call(stringIterator, `${$}`, []),
- false,
- ),
- scalarValueString: ($) =>
- stringFromCodepoints(...objectCreate(
- scalarValueIterablePrototype,
- { source: { value: `${$}` } },
- )),
+ characters: ($) => charactersIterator(`${$}`),
+ codeUnits: ($) => codeUnitsIterator(`${$}`),
+ codepoints: ($) => codepointsIterator(`${$}`),
+ scalarValues: ($) => scalarValuesIterator(`${$}`),
};
})();
-/**
- * Returns an iterator over the codepoints in the string representation
- * of the provided value according to the algorithm of
- * `String::[Symbol.iterator]`.
- */
-export const characters = makeCallable(
- stringPrototype[ITERATOR],
-);
-
/**
* Returns the character at the provided position in the string
* representation of the provided value according to the algorithm of
export const getCharacter = ($, pos) => {
const codepoint = getCodepoint($, pos);
return codepoint == null
- ? undefined
+ ? UNDEFINED
: stringFromCodepoints(codepoint);
};
-/**
- * Returns the code unit at the provided position in the string
- * representation of the provided value according to the algorithm of
- * `String::charAt`.
- */
-export const getCodeUnit = makeCallable(stringPrototype.charCodeAt);
+export const {
+ /**
+ * Returns the code unit at the provided position in the string
+ * representation of the provided value according to the algorithm of
+ * `String::charAt`, except that out‐of‐bounds values return undefined
+ * in place of nan.
+ */
+ getCodeUnit,
+
+ /**
+ * Returns a string created from the provided code units.
+ *
+ * ※ This is effectively an alias for `String.fromCharCode`, but
+ * with the same error behaviour as `String.fromCodePoint`.
+ *
+ * ☡ This function throws an error if provided with an argument which
+ * is not an integral number from 0 to FFFF₁₆ inclusive.
+ */
+ stringFromCodeUnits,
+
+ /**
+ * Returns the result of catenating the string representations of the
+ * provided values, returning a new string according to the algorithm
+ * of `String::concat`.
+ *
+ * ※ If no arguments are given, this function returns the empty
+ * string. This is different behaviour than if an explicit undefined
+ * first argument is given, in which case the resulting string will
+ * begin with `"undefined"`.
+ */
+ stringCatenate,
+} = (() => {
+ const { fromCharCode } = String;
+ const { charCodeAt, concat } = String.prototype;
+ const {
+ isInteger: isIntegralNumber,
+ isNaN: isNan,
+ } = Number;
+
+ return {
+ getCodeUnit: ($, n) => {
+ const codeUnit = call(charCodeAt, $, [n]);
+ return isNan(codeUnit) ? UNDEFINED : codeUnit;
+ },
+ stringCatenate: Object.defineProperties(
+ (...args) => call(concat, "", args),
+ { name: { value: "stringCatenate" }, length: { value: 2 } },
+ ),
+ stringFromCodeUnits: Object.defineProperties(
+ (...codeUnits) => {
+ for (let index = 0; index < codeUnits.length; ++index) {
+ // Iterate over each provided code unit and throw if it is
+ // out of range.
+ const nextCU = +codeUnits[index];
+ if (
+ !isIntegralNumber(nextCU) || nextCU < 0 || nextCU > 0xFFFF
+ ) {
+ // The code unit is not an integral number between 0 and
+ // 0xFFFF.
+ throw new RangeError(
+ `Piscēs: Code unit out of range: ${nextCU}.`,
+ );
+ } else {
+ // The code unit is acceptable.
+ /* do nothing */
+ }
+ }
+ return call(fromCharCode, UNDEFINED, codeUnits);
+ },
+ { name: { value: "stringFromCodeUnits" }, length: { value: 1 } },
+ ),
+ };
+})();
/**
* Returns the codepoint at the provided position in the string
* representation of the provided value according to the algorithm of
* `String::codePointAt`.
*/
-export const getCodepoint = makeCallable(stringPrototype.codePointAt);
+export const getCodepoint = createCallableFunction(
+ stringPrototype.codePointAt,
+ { name: "getCodepoint" },
+);
/**
* Returns the index of the first occurrence of the search string in
* the string representation of the provided value according to the
* algorithm of `String::indexOf`.
*/
-export const getFirstSubstringIndex = makeCallable(
+export const getFirstSubstringIndex = createCallableFunction(
stringPrototype.indexOf,
+ { name: "getFirstSubstringIndex" },
);
/**
* string representation of the provided value according to the
* algorithm of `String::lastIndexOf`.
*/
-export const getLastSubstringIndex = makeCallable(
+export const getLastSubstringIndex = createCallableFunction(
stringPrototype.lastIndexOf,
+ { name: "getLastSubstringIndex" },
);
+/** Returns whether the provided value is an array index. */
+export const isArrayIndexString = ($) => {
+ const value = canonicalNumericIndexString($);
+ if (value !== UNDEFINED) {
+ // The provided value is a canonical numeric index string; return
+ // whether it is in range for array indices.
+ return sameValue(value, 0) ||
+ value === toLength(value) && value > 0 && value < -1 >>> 0;
+ } else {
+ // The provided value is not a canonical numeric index string.
+ return false;
+ }
+};
+
+/** Returns whether the provided value is an integer index string. */
+export const isIntegerIndexString = ($) => {
+ const value = canonicalNumericIndexString($);
+ if (value !== UNDEFINED) {
+ // The provided value is a canonical numeric index string; return
+ // whether it is in range for integer indices.
+ return sameValue(value, 0) ||
+ value === toLength(value) && value > 0;
+ } else {
+ // The provided value is not a canonical numeric index string.
+ return false;
+ }
+};
+
/**
* Returns the result of joining the provided iterable.
*
*/
export const join = (() => {
const { join: arrayJoin } = arrayPrototype;
- const join = ($, separator = ",") =>
- call(arrayJoin, [...$], [`${separator}`]);
+ const join = ($, separator) =>
+ call(
+ arrayJoin,
+ [...$],
+ [separator === UNDEFINED ? "," : `${separator}`],
+ );
return join;
})();
-export const {
- /**
- * Returns a string created from the raw value of the tagged template
- * literal.
- *
- * ※ This is an alias for `String.raw`.
- */
- raw: rawString,
-
- /**
- * Returns a string created from the provided code units.
- *
- * ※ This is an alias for `String.fromCharCode`.
- */
- fromCharCode: stringFromCodeUnits,
+/**
+ * Returns a string created from the raw value of the tagged template
+ * literal.
+ *
+ * ※ This is effectively an alias for `String.raw`.
+ */
+export const rawString = createArrowFunction(String.raw, {
+ name: "rawString",
+});
- /**
- * Returns a string created from the provided codepoints.
- *
- * ※ This is an alias for `String.fromCodePoint`.
- */
- fromCodePoint: stringFromCodepoints,
-} = String;
+/**
+ * Returns a string created from the provided codepoints.
+ *
+ * ※ This is effectively an alias for `String.fromCodePoint`.
+ *
+ * ☡ This function throws an error if provided with an argument which
+ * is not an integral number from 0 to 10FFFF₁₆ inclusive.
+ */
+export const stringFromCodepoints = createArrowFunction(
+ String.fromCodePoint,
+ { name: "stringFromCodepoints" },
+);
/**
- * Returns the result of splitting the provided value on A·S·C·I·I
+ * Returns the result of splitting the provided value on Ascii
* whitespace.
*/
-export const splitOnASCIIWhitespace = ($) =>
- stringSplit(stripAndCollapseASCIIWhitespace($), " ");
+export const splitOnAsciiWhitespace = ($) =>
+ stringSplit(stripAndCollapseAsciiWhitespace($), " ");
/**
* Returns the result of splitting the provided value on commas,
- * trimming A·S·C·I·I whitespace from the resulting tokens.
+ * trimming Ascii whitespace from the resulting tokens.
*/
export const splitOnCommas = ($) =>
stringSplit(
- stripLeadingAndTrailingASCIIWhitespace(
+ stripLeadingAndTrailingAsciiWhitespace(
stringReplaceAll(
`${$}`,
/[\n\r\t\f ]*,[\n\r\t\f ]*/gu,
",",
);
-/**
- * Returns the result of catenating the string representations of the
- * provided values, returning a new string according to the algorithm
- * of `String::concat`.
- */
-export const stringCatenate = makeCallable(stringPrototype.concat);
-
/**
* Returns whether the string representation of the provided value ends
* with the provided search string according to the algorithm of
* `String::endsWith`.
*/
-export const stringEndsWith = makeCallable(stringPrototype.endsWith);
+export const stringEndsWith = createCallableFunction(
+ stringPrototype.endsWith,
+ { name: "stringEndsWith" },
+);
/**
* Returns whether the string representation of the provided value
* contains the provided search string according to the algorithm of
* `String::includes`.
*/
-export const stringIncludes = makeCallable(stringPrototype.includes);
+export const stringIncludes = createCallableFunction(
+ stringPrototype.includes,
+ { name: "stringIncludes" },
+);
/**
* Returns the result of matching the string representation of the
* provided value with the provided matcher according to the algorithm
* of `String::match`.
*/
-export const stringMatch = makeCallable(stringPrototype.match);
+export const stringMatch = createCallableFunction(
+ stringPrototype.match,
+ { name: "stringMatch" },
+);
/**
* Returns the result of matching the string representation of the
* provided value with the provided matcher according to the algorithm
* of `String::matchAll`.
*/
-export const stringMatchAll = makeCallable(stringPrototype.matchAll);
+export const stringMatchAll = createCallableFunction(
+ stringPrototype.matchAll,
+ { name: "stringMatchAll" },
+);
/**
* Returns the normalized form of the string representation of the
- * provided value according to the algorithm of `String::matchAll`.
+ * provided value according to the algorithm of `String::normalize`.
*/
-export const stringNormalize = makeCallable(
+export const stringNormalize = createCallableFunction(
stringPrototype.normalize,
+ { name: "stringNormalize" },
);
/**
* of the provided value padded until it is the desired length
* according to the algorithm of `String::padEnd`.
*/
-export const stringPadEnd = makeCallable(stringPrototype.padEnd);
+export const stringPadEnd = createCallableFunction(
+ stringPrototype.padEnd,
+ { name: "stringPadEnd" },
+);
/**
* Returns the result of padding the start of the string representation
* of the provided value padded until it is the desired length
* according to the algorithm of `String::padStart`.
*/
-export const stringPadStart = makeCallable(stringPrototype.padStart);
+export const stringPadStart = createCallableFunction(
+ stringPrototype.padStart,
+ { name: "stringPadStart" },
+);
/**
* Returns the result of repeating the string representation of the
* provided value the provided number of times according to the
* algorithm of `String::repeat`.
*/
-export const stringRepeat = makeCallable(stringPrototype.repeat);
+export const stringRepeat = createCallableFunction(
+ stringPrototype.repeat,
+ { name: "stringRepeat" },
+);
/**
* Returns the result of replacing the string representation of the
* provided value with the provided replacement, using the provided
* matcher and according to the algorithm of `String::replace`.
*/
-export const stringReplace = makeCallable(stringPrototype.replace);
+export const stringReplace = createCallableFunction(
+ stringPrototype.replace,
+ { name: "stringReplace" },
+);
/**
* Returns the result of replacing the string representation of the
* provided value with the provided replacement, using the provided
* matcher and according to the algorithm of `String::replaceAll`.
*/
-export const stringReplaceAll = makeCallable(
+export const stringReplaceAll = createCallableFunction(
stringPrototype.replaceAll,
+ { name: "stringReplaceAll" },
);
/**
* provided value using the provided matcher and according to the
* algorithm of `String::search`.
*/
-export const stringSearch = makeCallable(stringPrototype.search);
+export const stringSearch = createCallableFunction(
+ stringPrototype.search,
+ { name: "stringSearch" },
+);
/**
* Returns a slice of the string representation of the provided value
* according to the algorithm of `String::slice`.
*/
-export const stringSlice = makeCallable(stringPrototype.slice);
+export const stringSlice = createCallableFunction(
+ stringPrototype.slice,
+ { name: "stringSlice" },
+);
/**
* Returns the result of splitting of the string representation of the
* provided value on the provided separator according to the algorithm
* of `String::split`.
*/
-export const stringSplit = makeCallable(stringPrototype.split);
+export const stringSplit = createCallableFunction(
+ stringPrototype.split,
+ { name: "stringSplit" },
+);
/**
* Returns whether the string representation of the provided value
* starts with the provided search string according to the algorithm of
* `String::startsWith`.
*/
-export const stringStartsWith = makeCallable(
+export const stringStartsWith = createCallableFunction(
stringPrototype.startsWith,
+ { name: "stringStartsWith" },
);
/**
- * Returns the `[[StringData]]` of the provided value.
+ * Returns the value of the provided string.
+ *
+ * ※ This is effectively an alias for the `String::valueOf`.
*
- * ☡ This function will throw if the provided object does not have a
- * `[[StringData]]` internal slot.
+ * ☡ This function throws if the provided argument is not a string and
+ * does not have a `[[StringData]]` slot.
*/
-export const stringValue = makeCallable(stringPrototype.valueOf);
+export const stringValue = createCallableFunction(
+ stringPrototype.valueOf,
+ { name: "stringValue" },
+);
/**
- * Returns the result of stripping leading and trailing A·S·C·I·I
- * whitespace from the provided value and collapsing other A·S·C·I·I
+ * Returns the result of stripping leading and trailing Ascii
+ * whitespace from the provided value and collapsing other Ascii
* whitespace in the string representation of the provided value.
*/
-export const stripAndCollapseASCIIWhitespace = ($) =>
- stripLeadingAndTrailingASCIIWhitespace(
+export const stripAndCollapseAsciiWhitespace = ($) =>
+ stripLeadingAndTrailingAsciiWhitespace(
stringReplaceAll(
`${$}`,
/[\n\r\t\f ]+/gu,
);
/**
- * Returns the result of stripping leading and trailing A·S·C·I·I
+ * Returns the result of stripping leading and trailing Ascii
* whitespace from the string representation of the provided value.
*/
-export const stripLeadingAndTrailingASCIIWhitespace = ($) =>
+export const stripLeadingAndTrailingAsciiWhitespace = ($) =>
call(reExec, /^[\n\r\t\f ]*([^]*?)[\n\r\t\f ]*$/u, [$])[1];
/**
* Returns a substring of the string representation of the provided
* value according to the algorithm of `String::substring`.
*/
-export const substring = makeCallable(stringPrototype.substring);
+export const substring = createCallableFunction(
+ stringPrototype.substring,
+);
+
+/**
+ * Returns the result of converting the provided value to a string of
+ * scalar values by replacing (unpaired) surrogate values with
+ * U+FFFD.
+ */
+export const toScalarValueString = createCallableFunction(
+ String.prototype.toWellFormed,
+ { name: "toScalarValueString" },
+);
/**
* Returns the result of converting the provided value to a string.