You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

771 lines
24 KiB
JavaScript

5 years ago
// json5.js
// Modern JSON. See README.md for details.
//
// This file is based directly off of Douglas Crockford's json_parse.js:
// https://github.com/douglascrockford/JSON-js/blob/master/json_parse.js
var JSON5 = (typeof exports === 'object' ? exports : {});
JSON5.parse = (function () {
"use strict";
// This is a function that can parse a JSON5 text, producing a JavaScript
// data structure. It is a simple, recursive descent parser. It does not use
// eval or regular expressions, so it can be used as a model for implementing
// a JSON5 parser in other languages.
// We are defining the function inside of another function to avoid creating
// global variables.
var at, // The index of the current character
lineNumber, // The current line number
columnNumber, // The current column number
ch, // The current character
escapee = {
"'": "'",
'"': '"',
'\\': '\\',
'/': '/',
'\n': '', // Replace escaped newlines in strings w/ empty string
b: '\b',
f: '\f',
n: '\n',
r: '\r',
t: '\t'
},
ws = [
' ',
'\t',
'\r',
'\n',
'\v',
'\f',
'\xA0',
'\uFEFF'
],
text,
renderChar = function (chr) {
return chr === '' ? 'EOF' : "'" + chr + "'";
},
error = function (m) {
// Call error when something is wrong.
var error = new SyntaxError();
// beginning of message suffix to agree with that provided by Gecko - see https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
error.message = m + " at line " + lineNumber + " column " + columnNumber + " of the JSON5 data. Still to read: " + JSON.stringify(text.substring(at - 1, at + 19));
error.at = at;
// These two property names have been chosen to agree with the ones in Gecko, the only popular
// environment which seems to supply this info on JSON.parse
error.lineNumber = lineNumber;
error.columnNumber = columnNumber;
throw error;
},
next = function (c) {
// If a c parameter is provided, verify that it matches the current character.
if (c && c !== ch) {
error("Expected " + renderChar(c) + " instead of " + renderChar(ch));
}
// Get the next character. When there are no more characters,
// return the empty string.
ch = text.charAt(at);
at++;
columnNumber++;
if (ch === '\n' || ch === '\r' && peek() !== '\n') {
lineNumber++;
columnNumber = 0;
}
return ch;
},
peek = function () {
// Get the next character without consuming it or
// assigning it to the ch varaible.
return text.charAt(at);
},
identifier = function () {
// Parse an identifier. Normally, reserved words are disallowed here, but we
// only use this for unquoted object keys, where reserved words are allowed,
// so we don't check for those here. References:
// - http://es5.github.com/#x7.6
// - https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Core_Language_Features#Variables
// - http://docstore.mik.ua/orelly/webprog/jscript/ch02_07.htm
// TODO Identifiers can have Unicode "letters" in them; add support for those.
var key = ch;
// Identifiers must start with a letter, _ or $.
if ((ch !== '_' && ch !== '$') &&
(ch < 'a' || ch > 'z') &&
(ch < 'A' || ch > 'Z')) {
error("Bad identifier as unquoted key");
}
// Subsequent characters can contain digits.
while (next() && (
ch === '_' || ch === '$' ||
(ch >= 'a' && ch <= 'z') ||
(ch >= 'A' && ch <= 'Z') ||
(ch >= '0' && ch <= '9'))) {
key += ch;
}
return key;
},
number = function () {
// Parse a number value.
var number,
sign = '',
string = '',
base = 10;
if (ch === '-' || ch === '+') {
sign = ch;
next(ch);
}
// support for Infinity (could tweak to allow other words):
if (ch === 'I') {
number = word();
if (typeof number !== 'number' || isNaN(number)) {
error('Unexpected word for number');
}
return (sign === '-') ? -number : number;
}
// support for NaN
if (ch === 'N' ) {
number = word();
if (!isNaN(number)) {
error('expected word to be NaN');
}
// ignore sign as -NaN also is NaN
return number;
}
if (ch === '0') {
string += ch;
next();
if (ch === 'x' || ch === 'X') {
string += ch;
next();
base = 16;
} else if (ch >= '0' && ch <= '9') {
error('Octal literal');
}
}
switch (base) {
case 10:
while (ch >= '0' && ch <= '9' ) {
string += ch;
next();
}
if (ch === '.') {
string += '.';
while (next() && ch >= '0' && ch <= '9') {
string += ch;
}
}
if (ch === 'e' || ch === 'E') {
string += ch;
next();
if (ch === '-' || ch === '+') {
string += ch;
next();
}
while (ch >= '0' && ch <= '9') {
string += ch;
next();
}
}
break;
case 16:
while (ch >= '0' && ch <= '9' || ch >= 'A' && ch <= 'F' || ch >= 'a' && ch <= 'f') {
string += ch;
next();
}
break;
}
if(sign === '-') {
number = -string;
} else {
number = +string;
}
if (!isFinite(number)) {
error("Bad number");
} else {
return number;
}
},
string = function () {
// Parse a string value.
var hex,
i,
string = '',
delim, // double quote or single quote
uffff;
// When parsing for string values, we must look for ' or " and \ characters.
if (ch === '"' || ch === "'") {
delim = ch;
while (next()) {
if (ch === delim) {
next();
return string;
} else if (ch === '\\') {
next();
if (ch === 'u') {
uffff = 0;
for (i = 0; i < 4; i += 1) {
hex = parseInt(next(), 16);
if (!isFinite(hex)) {
break;
}
uffff = uffff * 16 + hex;
}
string += String.fromCharCode(uffff);
} else if (ch === '\r') {
if (peek() === '\n') {
next();
}
} else if (typeof escapee[ch] === 'string') {
string += escapee[ch];
} else {
break;
}
} else if (ch === '\n') {
// unescaped newlines are invalid; see:
// https://github.com/aseemk/json5/issues/24
// TODO this feels special-cased; are there other
// invalid unescaped chars?
break;
} else {
string += ch;
}
}
}
error("Bad string");
},
inlineComment = function () {
// Skip an inline comment, assuming this is one. The current character should
// be the second / character in the // pair that begins this inline comment.
// To finish the inline comment, we look for a newline or the end of the text.
if (ch !== '/') {
error("Not an inline comment");
}
do {
next();
if (ch === '\n' || ch === '\r') {
next();
return;
}
} while (ch);
},
blockComment = function () {
// Skip a block comment, assuming this is one. The current character should be
// the * character in the /* pair that begins this block comment.
// To finish the block comment, we look for an ending */ pair of characters,
// but we also watch for the end of text before the comment is terminated.
if (ch !== '*') {
error("Not a block comment");
}
do {
next();
while (ch === '*') {
next('*');
if (ch === '/') {
next('/');
return;
}
}
} while (ch);
error("Unterminated block comment");
},
comment = function () {
// Skip a comment, whether inline or block-level, assuming this is one.
// Comments always begin with a / character.
if (ch !== '/') {
error("Not a comment");
}
next('/');
if (ch === '/') {
inlineComment();
} else if (ch === '*') {
blockComment();
} else {
error("Unrecognized comment");
}
},
white = function () {
// Skip whitespace and comments.
// Note that we're detecting comments by only a single / character.
// This works since regular expressions are not valid JSON(5), but this will
// break if there are other valid values that begin with a / character!
while (ch) {
if (ch === '/') {
comment();
} else if (ws.indexOf(ch) >= 0) {
next();
} else {
return;
}
}
},
word = function () {
// true, false, or null.
switch (ch) {
case 't':
next('t');
next('r');
next('u');
next('e');
return true;
case 'f':
next('f');
next('a');
next('l');
next('s');
next('e');
return false;
case 'n':
next('n');
next('u');
next('l');
next('l');
return null;
case 'I':
next('I');
next('n');
next('f');
next('i');
next('n');
next('i');
next('t');
next('y');
return Infinity;
case 'N':
next( 'N' );
next( 'a' );
next( 'N' );
return NaN;
}
error("Unexpected " + renderChar(ch));
},
value, // Place holder for the value function.
array = function () {
// Parse an array value.
var array = [];
if (ch === '[') {
next('[');
white();
while (ch) {
if (ch === ']') {
next(']');
return array; // Potentially empty array
}
// ES5 allows omitting elements in arrays, e.g. [,] and
// [,null]. We don't allow this in JSON5.
if (ch === ',') {
error("Missing array element");
} else {
array.push(value());
}
white();
// If there's no comma after this value, this needs to
// be the end of the array.
if (ch !== ',') {
next(']');
return array;
}
next(',');
white();
}
}
error("Bad array");
},
object = function () {
// Parse an object value.
var key,
object = {};
if (ch === '{') {
next('{');
white();
while (ch) {
if (ch === '}') {
next('}');
return object; // Potentially empty object
}
// Keys can be unquoted. If they are, they need to be
// valid JS identifiers.
if (ch === '"' || ch === "'") {
key = string();
} else {
key = identifier();
}
white();
next(':');
object[key] = value();
white();
// If there's no comma after this pair, this needs to be
// the end of the object.
if (ch !== ',') {
next('}');
return object;
}
next(',');
white();
}
}
error("Bad object");
};
value = function () {
// Parse a JSON value. It could be an object, an array, a string, a number,
// or a word.
white();
switch (ch) {
case '{':
return object();
case '[':
return array();
case '"':
case "'":
return string();
case '-':
case '+':
case '.':
return number();
default:
return ch >= '0' && ch <= '9' ? number() : word();
}
};
// Return the json_parse function. It will have access to all of the above
// functions and variables.
return function (source, reviver) {
var result;
text = String(source);
at = 0;
lineNumber = 1;
columnNumber = 1;
ch = ' ';
result = value();
white();
if (ch) {
error("Syntax error");
}
// If there is a reviver function, we recursively walk the new structure,
// passing each name/value pair to the reviver function for possible
// transformation, starting with a temporary root object that holds the result
// in an empty key. If there is not a reviver function, we simply return the
// result.
return typeof reviver === 'function' ? (function walk(holder, key) {
var k, v, value = holder[key];
if (value && typeof value === 'object') {
for (k in value) {
if (Object.prototype.hasOwnProperty.call(value, k)) {
v = walk(value, k);
if (v !== undefined) {
value[k] = v;
} else {
delete value[k];
}
}
}
}
return reviver.call(holder, key, value);
}({'': result}, '')) : result;
};
}());
// JSON5 stringify will not quote keys where appropriate
JSON5.stringify = function (obj, replacer, space) {
if (replacer && (typeof(replacer) !== "function" && !isArray(replacer))) {
throw new Error('Replacer must be a function or an array');
}
var getReplacedValueOrUndefined = function(holder, key, isTopLevel) {
var value = holder[key];
// Replace the value with its toJSON value first, if possible
if (value && value.toJSON && typeof value.toJSON === "function") {
value = value.toJSON();
}
// If the user-supplied replacer if a function, call it. If it's an array, check objects' string keys for
// presence in the array (removing the key/value pair from the resulting JSON if the key is missing).
if (typeof(replacer) === "function") {
return replacer.call(holder, key, value);
} else if(replacer) {
if (isTopLevel || isArray(holder) || replacer.indexOf(key) >= 0) {
return value;
} else {
return undefined;
}
} else {
return value;
}
};
function isWordChar(c) {
return (c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c === '_' || c === '$';
}
function isWordStart(c) {
return (c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
c === '_' || c === '$';
}
function isWord(key) {
if (typeof key !== 'string') {
return false;
}
if (!isWordStart(key[0])) {
return false;
}
var i = 1, length = key.length;
while (i < length) {
if (!isWordChar(key[i])) {
return false;
}
i++;
}
return true;
}
// export for use in tests
JSON5.isWord = isWord;
// polyfills
function isArray(obj) {
if (Array.isArray) {
return Array.isArray(obj);
} else {
return Object.prototype.toString.call(obj) === '[object Array]';
}
}
function isDate(obj) {
return Object.prototype.toString.call(obj) === '[object Date]';
}
var objStack = [];
function checkForCircular(obj) {
for (var i = 0; i < objStack.length; i++) {
if (objStack[i] === obj) {
throw new TypeError("Converting circular structure to JSON");
}
}
}
function makeIndent(str, num, noNewLine) {
if (!str) {
return "";
}
// indentation no more than 10 chars
if (str.length > 10) {
str = str.substring(0, 10);
}
var indent = noNewLine ? "" : "\n";
for (var i = 0; i < num; i++) {
indent += str;
}
return indent;
}
var indentStr;
if (space) {
if (typeof space === "string") {
indentStr = space;
} else if (typeof space === "number" && space >= 0) {
indentStr = makeIndent(" ", space, true);
} else {
// ignore space parameter
}
}
// Copied from Crokford's implementation of JSON
// See https://github.com/douglascrockford/JSON-js/blob/e39db4b7e6249f04a195e7dd0840e610cc9e941e/json2.js#L195
// Begin
var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
meta = { // table of character substitutions
'\b': '\\b',
'\t': '\\t',
'\n': '\\n',
'\f': '\\f',
'\r': '\\r',
'"' : '\\"',
'\\': '\\\\'
};
function escapeString(string) {
// If the string contains no control characters, no quote characters, and no
// backslash characters, then we can safely slap some quotes around it.
// Otherwise we must also replace the offending characters with safe escape
// sequences.
escapable.lastIndex = 0;
return escapable.test(string) ? '"' + string.replace(escapable, function (a) {
var c = meta[a];
return typeof c === 'string' ?
c :
'\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
}) + '"' : '"' + string + '"';
}
// End
function internalStringify(holder, key, isTopLevel) {
var buffer, res;
// Replace the value, if necessary
var obj_part = getReplacedValueOrUndefined(holder, key, isTopLevel);
if (obj_part && !isDate(obj_part)) {
// unbox objects
// don't unbox dates, since will turn it into number
obj_part = obj_part.valueOf();
}
switch(typeof obj_part) {
case "boolean":
return obj_part.toString();
case "number":
if (isNaN(obj_part) || !isFinite(obj_part)) {
return "null";
}
return obj_part.toString();
case "string":
return escapeString(obj_part.toString());
case "object":
if (obj_part === null) {
return "null";
} else if (isArray(obj_part)) {
checkForCircular(obj_part);
buffer = "[";
objStack.push(obj_part);
for (var i = 0; i < obj_part.length; i++) {
res = internalStringify(obj_part, i, false);
buffer += makeIndent(indentStr, objStack.length);
if (res === null || typeof res === "undefined") {
buffer += "null";
} else {
buffer += res;
}
if (i < obj_part.length-1) {
buffer += ",";
} else if (indentStr) {
buffer += "\n";
}
}
objStack.pop();
if (obj_part.length) {
buffer += makeIndent(indentStr, objStack.length, true)
}
buffer += "]";
} else {
checkForCircular(obj_part);
buffer = "{";
var nonEmpty = false;
objStack.push(obj_part);
for (var prop in obj_part) {
if (obj_part.hasOwnProperty(prop)) {
var value = internalStringify(obj_part, prop, false);
isTopLevel = false;
if (typeof value !== "undefined" && value !== null) {
buffer += makeIndent(indentStr, objStack.length);
nonEmpty = true;
key = isWord(prop) ? prop : escapeString(prop);
buffer += key + ":" + (indentStr ? ' ' : '') + value + ",";
}
}
}
objStack.pop();
if (nonEmpty) {
buffer = buffer.substring(0, buffer.length-1) + makeIndent(indentStr, objStack.length) + "}";
} else {
buffer = '{}';
}
}
return buffer;
default:
// functions and undefined should be ignored
return undefined;
}
}
// special case...when undefined is used inside of
// a compound object/array, return null.
// but when top-level, return undefined
var topLevelHolder = {"":obj};
if (obj === undefined) {
return getReplacedValueOrUndefined(topLevelHolder, '', true);
}
return internalStringify(topLevelHolder, '', true);
};