playcanvas
Version:
PlayCanvas WebGL game engine
214 lines (212 loc) • 7.71 kB
JavaScript
var ASCII_LOWERCASE = 'abcdefghijklmnopqrstuvwxyz';
var ASCII_UPPERCASE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
var ASCII_LETTERS = ASCII_LOWERCASE + ASCII_UPPERCASE;
var HIGH_SURROGATE_BEGIN = 0xD800;
var HIGH_SURROGATE_END = 0xDBFF;
var LOW_SURROGATE_BEGIN = 0xDC00;
var LOW_SURROGATE_END = 0xDFFF;
var ZERO_WIDTH_JOINER = 0x200D;
// Flag emoji
var REGIONAL_INDICATOR_BEGIN = 0x1F1E6;
var REGIONAL_INDICATOR_END = 0x1F1FF;
// Skin color modifications to emoji
var FITZPATRICK_MODIFIER_BEGIN = 0x1F3FB;
var FITZPATRICK_MODIFIER_END = 0x1F3FF;
// Accent characters
var DIACRITICAL_MARKS_BEGIN = 0x20D0;
var DIACRITICAL_MARKS_END = 0x20FF;
// Special emoji joins
var VARIATION_MODIFIER_BEGIN = 0xFE00;
var VARIATION_MODIFIER_END = 0xFE0F;
function getCodePointData(string, i) {
if (i === void 0) i = 0;
var size = string.length;
// Account for out-of-bounds indices:
if (i < 0 || i >= size) {
return null;
}
var first = string.charCodeAt(i);
if (size > 1 && first >= HIGH_SURROGATE_BEGIN && first <= HIGH_SURROGATE_END) {
var second = string.charCodeAt(i + 1);
if (second >= LOW_SURROGATE_BEGIN && second <= LOW_SURROGATE_END) {
// https://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
return {
code: (first - HIGH_SURROGATE_BEGIN) * 0x400 + second - LOW_SURROGATE_BEGIN + 0x10000,
long: true
};
}
}
return {
code: first,
long: false
};
}
function isCodeBetween(string, begin, end) {
if (!string) {
return false;
}
var codeData = getCodePointData(string);
if (codeData) {
var code = codeData.code;
return code >= begin && code <= end;
}
return false;
}
function numCharsToTakeForNextSymbol(string, index) {
if (index === string.length - 1) {
// Last character in the string, so we can only take 1
return 1;
}
if (isCodeBetween(string[index], HIGH_SURROGATE_BEGIN, HIGH_SURROGATE_END)) {
var first = string.substring(index, index + 2);
var second = string.substring(index + 2, index + 4);
// check if second character is fitzpatrick (color) modifier
// or if this is a pair of regional indicators (a flag)
if (isCodeBetween(second, FITZPATRICK_MODIFIER_BEGIN, FITZPATRICK_MODIFIER_END) || isCodeBetween(first, REGIONAL_INDICATOR_BEGIN, REGIONAL_INDICATOR_END) && isCodeBetween(second, REGIONAL_INDICATOR_BEGIN, REGIONAL_INDICATOR_END)) {
return 4;
}
// check if next character is a modifier, in which case we should return it
if (isCodeBetween(second, VARIATION_MODIFIER_BEGIN, VARIATION_MODIFIER_END)) {
return 3;
}
// return surrogate pair
return 2;
}
// check if next character is the emoji modifier, in which case we should include it
if (isCodeBetween(string[index + 1], VARIATION_MODIFIER_BEGIN, VARIATION_MODIFIER_END)) {
return 2;
}
// just a regular character
return 1;
}
/**
* Extended String API.
*
* @namespace
*/ var string = {
/**
* All lowercase letters.
*
* @type {string}
*/ ASCII_LOWERCASE: ASCII_LOWERCASE,
/**
* All uppercase letters.
*
* @type {string}
*/ ASCII_UPPERCASE: ASCII_UPPERCASE,
/**
* All ASCII letters.
*
* @type {string}
*/ ASCII_LETTERS: ASCII_LETTERS,
/**
* Return a string with \{n\} replaced with the n-th argument.
*
* @param {string} s - The string to format.
* @param {...*} args - All other arguments are substituted into the string.
* @returns {string} The formatted string.
* @example
* const s = pc.string.format("Hello {0}", "world");
* console.log(s); // Prints "Hello world"
*/ format (s) {
for(var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++){
args[_key - 1] = arguments[_key];
}
for(var i = 0; i < args.length; i++){
s = s.replace("{" + i + "}", args[i]);
}
return s;
},
/**
* Get the code point number for a character in a string. Polyfill for
* [`codePointAt`]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/codePointAt}.
*
* @param {string} string - The string to get the code point from.
* @param {number} [i] - The index in the string.
* @returns {number} The code point value for the character in the string.
*/ getCodePoint (string, i) {
var codePointData = getCodePointData(string, i);
return codePointData && codePointData.code;
},
/**
* Gets an array of all code points in a string.
*
* @param {string} string - The string to get code points from.
* @returns {number[]} The code points in the string.
*/ getCodePoints (string) {
if (typeof string !== 'string') {
throw new TypeError('Not a string');
}
var i = 0;
var arr = [];
var codePoint;
while(!!(codePoint = getCodePointData(string, i))){
arr.push(codePoint.code);
i += codePoint.long ? 2 : 1;
}
return arr;
},
/**
* Gets an array of all grapheme clusters (visible symbols) in a string. This is needed because
* some symbols (such as emoji or accented characters) are actually made up of multiple
* character codes. See {@link https://mathiasbynens.be/notes/javascript-unicode here} for more
* info.
*
* @param {string} string - The string to break into symbols.
* @returns {string[]} The symbols in the string.
*/ getSymbols (string) {
if (typeof string !== 'string') {
throw new TypeError('Not a string');
}
var index = 0;
var length = string.length;
var output = [];
var take = 0;
var ch;
while(index < length){
take += numCharsToTakeForNextSymbol(string, index + take);
ch = string[index + take];
// Handle special cases
if (isCodeBetween(ch, DIACRITICAL_MARKS_BEGIN, DIACRITICAL_MARKS_END)) {
ch = string[index + take++];
}
if (isCodeBetween(ch, VARIATION_MODIFIER_BEGIN, VARIATION_MODIFIER_END)) {
ch = string[index + take++];
}
if (ch && ch.charCodeAt(0) === ZERO_WIDTH_JOINER) {
ch = string[index + take++];
continue;
}
var char = string.substring(index, index + take);
output.push(char);
index += take;
take = 0;
}
return output;
},
/**
* Get the string for a given code point or set of code points. Polyfill for
* [`fromCodePoint`]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/fromCodePoint}.
*
* @param {...number} args - The code points to convert to a string.
* @returns {string} The converted string.
*/ fromCodePoint () {
var chars = [];
var current;
var codePoint;
var units;
for(var i = 0; i < arguments.length; ++i){
current = Number(arguments[i]);
codePoint = current - 0x10000;
units = current > 0xFFFF ? [
(codePoint >> 10) + 0xD800,
codePoint % 0x400 + 0xDC00
] : [
current
];
chars.push(String.fromCharCode.apply(null, units));
}
return chars.join('');
}
};
export { string };