install-nix-action/node_modules/webidl-conversions/lib/index.js
Domen Kožar 49df04613e
v7
2020-02-24 13:29:22 +01:00

332 lines
9 KiB
JavaScript

"use strict";
function _(message, opts) {
return `${opts && opts.context ? opts.context : "Value"} ${message}.`;
}
function type(V) {
if (V === null) {
return "Null";
}
switch (typeof V) {
case "undefined":
return "Undefined";
case "boolean":
return "Boolean";
case "number":
return "Number";
case "string":
return "String";
case "symbol":
return "Symbol";
case "object":
// Falls through
case "function":
// Falls through
default:
// Per ES spec, typeof returns an implemention-defined value that is not any of the existing ones for
// uncallable non-standard exotic objects. Yet Type() which the Web IDL spec depends on returns Object for
// such cases. So treat the default case as an object.
return "Object";
}
}
// Round x to the nearest integer, choosing the even integer if it lies halfway between two.
function evenRound(x) {
// There are four cases for numbers with fractional part being .5:
//
// case | x | floor(x) | round(x) | expected | x <> 0 | x % 1 | x & 1 | example
// 1 | 2n + 0.5 | 2n | 2n + 1 | 2n | > | 0.5 | 0 | 0.5 -> 0
// 2 | 2n + 1.5 | 2n + 1 | 2n + 2 | 2n + 2 | > | 0.5 | 1 | 1.5 -> 2
// 3 | -2n - 0.5 | -2n - 1 | -2n | -2n | < | -0.5 | 0 | -0.5 -> 0
// 4 | -2n - 1.5 | -2n - 2 | -2n - 1 | -2n - 2 | < | -0.5 | 1 | -1.5 -> -2
// (where n is a non-negative integer)
//
// Branch here for cases 1 and 4
if ((x > 0 && (x % 1) === +0.5 && (x & 1) === 0) ||
(x < 0 && (x % 1) === -0.5 && (x & 1) === 1)) {
return censorNegativeZero(Math.floor(x));
}
return censorNegativeZero(Math.round(x));
}
function integerPart(n) {
return censorNegativeZero(Math.trunc(n));
}
function sign(x) {
return x < 0 ? -1 : 1;
}
function modulo(x, y) {
// https://tc39.github.io/ecma262/#eqn-modulo
// Note that http://stackoverflow.com/a/4467559/3191 does NOT work for large modulos
const signMightNotMatch = x % y;
if (sign(y) !== sign(signMightNotMatch)) {
return signMightNotMatch + y;
}
return signMightNotMatch;
}
function censorNegativeZero(x) {
return x === 0 ? 0 : x;
}
function createIntegerConversion(bitLength, typeOpts) {
const isSigned = !typeOpts.unsigned;
let lowerBound;
let upperBound;
if (bitLength === 64) {
upperBound = Math.pow(2, 53) - 1;
lowerBound = !isSigned ? 0 : -Math.pow(2, 53) + 1;
} else if (!isSigned) {
lowerBound = 0;
upperBound = Math.pow(2, bitLength) - 1;
} else {
lowerBound = -Math.pow(2, bitLength - 1);
upperBound = Math.pow(2, bitLength - 1) - 1;
}
const twoToTheBitLength = Math.pow(2, bitLength);
const twoToOneLessThanTheBitLength = Math.pow(2, bitLength - 1);
return (V, opts) => {
if (opts === undefined) {
opts = {};
}
let x = +V;
x = censorNegativeZero(x); // Spec discussion ongoing: https://github.com/heycam/webidl/issues/306
if (opts.enforceRange) {
if (!Number.isFinite(x)) {
throw new TypeError(_("is not a finite number", opts));
}
x = integerPart(x);
if (x < lowerBound || x > upperBound) {
throw new TypeError(_(
`is outside the accepted range of ${lowerBound} to ${upperBound}, inclusive`, opts));
}
return x;
}
if (!Number.isNaN(x) && opts.clamp) {
x = Math.min(Math.max(x, lowerBound), upperBound);
x = evenRound(x);
return x;
}
if (!Number.isFinite(x) || x === 0) {
return 0;
}
x = integerPart(x);
// Math.pow(2, 64) is not accurately representable in JavaScript, so try to avoid these per-spec operations if
// possible. Hopefully it's an optimization for the non-64-bitLength cases too.
if (x >= lowerBound && x <= upperBound) {
return x;
}
// These will not work great for bitLength of 64, but oh well. See the README for more details.
x = modulo(x, twoToTheBitLength);
if (isSigned && x >= twoToOneLessThanTheBitLength) {
return x - twoToTheBitLength;
}
return x;
};
}
exports.any = V => {
return V;
};
exports.void = function () {
return undefined;
};
exports.boolean = function (val) {
return !!val;
};
exports.byte = createIntegerConversion(8, { unsigned: false });
exports.octet = createIntegerConversion(8, { unsigned: true });
exports.short = createIntegerConversion(16, { unsigned: false });
exports["unsigned short"] = createIntegerConversion(16, { unsigned: true });
exports.long = createIntegerConversion(32, { unsigned: false });
exports["unsigned long"] = createIntegerConversion(32, { unsigned: true });
exports["long long"] = createIntegerConversion(64, { unsigned: false });
exports["unsigned long long"] = createIntegerConversion(64, { unsigned: true });
exports.double = (V, opts) => {
const x = +V;
if (!Number.isFinite(x)) {
throw new TypeError(_("is not a finite floating-point value", opts));
}
return x;
};
exports["unrestricted double"] = V => {
const x = +V;
return x;
};
exports.float = (V, opts) => {
const x = +V;
if (!Number.isFinite(x)) {
throw new TypeError(_("is not a finite floating-point value", opts));
}
if (Object.is(x, -0)) {
return x;
}
const y = Math.fround(x);
if (!Number.isFinite(y)) {
throw new TypeError(_("is outside the range of a single-precision floating-point value", opts));
}
return y;
};
exports["unrestricted float"] = V => {
const x = +V;
if (isNaN(x)) {
return x;
}
if (Object.is(x, -0)) {
return x;
}
return Math.fround(x);
};
exports.DOMString = function (V, opts) {
if (opts === undefined) {
opts = {};
}
if (opts.treatNullAsEmptyString && V === null) {
return "";
}
if (typeof V === "symbol") {
throw new TypeError(_("is a symbol, which cannot be converted to a string", opts));
}
return String(V);
};
exports.ByteString = (V, opts) => {
const x = exports.DOMString(V, opts);
let c;
for (let i = 0; (c = x.codePointAt(i)) !== undefined; ++i) {
if (c > 255) {
throw new TypeError(_("is not a valid ByteString", opts));
}
}
return x;
};
exports.USVString = (V, opts) => {
const S = exports.DOMString(V, opts);
const n = S.length;
const U = [];
for (let i = 0; i < n; ++i) {
const c = S.charCodeAt(i);
if (c < 0xD800 || c > 0xDFFF) {
U.push(String.fromCodePoint(c));
} else if (0xDC00 <= c && c <= 0xDFFF) {
U.push(String.fromCodePoint(0xFFFD));
} else if (i === n - 1) {
U.push(String.fromCodePoint(0xFFFD));
} else {
const d = S.charCodeAt(i + 1);
if (0xDC00 <= d && d <= 0xDFFF) {
const a = c & 0x3FF;
const b = d & 0x3FF;
U.push(String.fromCodePoint((2 << 15) + ((2 << 9) * a) + b));
++i;
} else {
U.push(String.fromCodePoint(0xFFFD));
}
}
}
return U.join("");
};
exports.object = (V, opts) => {
if (type(V) !== "Object") {
throw new TypeError(_("is not an object", opts));
}
return V;
};
// Not exported, but used in Function and VoidFunction.
// Neither Function nor VoidFunction is defined with [TreatNonObjectAsNull], so
// handling for that is omitted.
function convertCallbackFunction(V, opts) {
if (typeof V !== "function") {
throw new TypeError(_("is not a function", opts));
}
return V;
}
[
Error,
ArrayBuffer, // The IsDetachedBuffer abstract operation is not exposed in JS
DataView, Int8Array, Int16Array, Int32Array, Uint8Array,
Uint16Array, Uint32Array, Uint8ClampedArray, Float32Array, Float64Array
].forEach(func => {
const name = func.name;
const article = /^[AEIOU]/.test(name) ? "an" : "a";
exports[name] = (V, opts) => {
if (!(V instanceof func)) {
throw new TypeError(_(`is not ${article} ${name} object`, opts));
}
return V;
};
});
// Common definitions
exports.ArrayBufferView = (V, opts) => {
if (!ArrayBuffer.isView(V)) {
throw new TypeError(_("is not a view on an ArrayBuffer object", opts));
}
return V;
};
exports.BufferSource = (V, opts) => {
if (!(ArrayBuffer.isView(V) || V instanceof ArrayBuffer)) {
throw new TypeError(_("is not an ArrayBuffer object or a view on one", opts));
}
return V;
};
exports.DOMTimeStamp = exports["unsigned long long"];
exports.Function = convertCallbackFunction;
exports.VoidFunction = convertCallbackFunction;