relaxed-json.js
/*
Copyright (c) 2013, Oleg Grenrus
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of the Oleg Grenrus nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL OLEG GRENRUS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
(function () {
"use strict";
/*
slightly different from ES5 some, without cast to boolean
[x, y, z].some(f):
ES5: !! ( f(x) || f(y) || f(z) || false)
this: ( f(x) || f(y) || f(z) || false)
*/
// :: array -> fn -> *
function some(array, f) {
var acc = false;
for (var i = 0; i < array.length; i++) {
acc = f(array[i], i, array);
if (acc) {
return acc;
}
}
return acc;
}
// typify: type tokenSpec = { re: regexp, f : fn }
// typify: type tokenType = "atom" | "number" | "string" | "[" | "]" | "{" | "}" | ":" | "," | " " | "eof"
// typify: type rawToken = { type: tokenType, match: string, value: any }
// typify: type token = rawToken & { line: nat }
// typify: type parseToken = { type: tokenType, value: any, line: nat }
// :: array tokenSpec -> fn
function makeLexer(tokenSpecs) {
// :: string -> array token
return function (contents) {
var tokens = [];
var line = 1;
// :: -> { raw: string, matched: * } | null
function findToken() {
return some(tokenSpecs, function (tokenSpec) {
var m = tokenSpec.re.exec(contents);
if (m) {
var raw = m[0];
contents = contents.slice(raw.length);
return {
raw: raw,
matched: tokenSpec.f(m),
};
} else {
return undefined;
}
});
}
while (contents !== "") {
var matched = findToken();
if (!matched) {
var err = new SyntaxError("Unexpected character: " + contents[0] + "; input: " + contents.substr(0, 100));
err.line = line;
throw err;
}
// add line to token
matched.matched.line = line;
// count lines
line += matched.raw.replace(/[^\n]/g, "").length;
tokens.push(matched.matched);
}
return tokens;
};
}
// :: tuple string string -> rawToken
function fStringSingle(m) {
// String in single quotes
var content = m[1].replace(/([^'\\]|\\['bnrtf\\]|\\u[0-9a-fA-F]{4})/g, function (mm) {
if (mm === "\"") {
return "\\\"";
} else if (mm === "\\'") {
return "'";
} else {
return mm;
}
});
return {
type: "string",
match: "\"" + content + "\"",
value: JSON.parse("\"" + content + "\""), // abusing real JSON.parse to unquote string
};
}
// :: tuple string -> rawToken
function fStringDouble(m) {
return {
type: "string",
match: m[0],
value: JSON.parse(m[0]),
};
}
// :: tuple string -> rawToken
function fIdentifier(m) {
// identifiers are transformed into strings
return {
type: "string",
value: m[0],
match: "\"" + m[0].replace(/./g, function (c) {
return c === "\\" ? "\\\\" : c;
}) + "\"",
};
}
// :: tuple string -> rawToken
function fComment(m) {
// comments are whitespace, leave only linefeeds
return {
type: " ",
match: m[0].replace(/./g, function (c) {
return (/\s/).test(c) ? c : " ";
}),
};
}
// :: tuple string -> rawToken
function fNumber(m) {
return {
type: "number",
match: m[0],
value: parseFloat(m[0]),
};
}
// :: tuple ("null" | "true" | "false") -> rawToken
function fKeyword(m) {
var value;
switch (m[0]) {
case "null": value = null; break;
case "true": value = true; break;
case "false": value = false; break;
// no default
}
return {
type: "atom",
match: m[0],
value: value,
};
}
// :: boolean -> array tokenSpec
function makeTokenSpecs(relaxed) {
// :: string -> fn
function f(type) {
// :: tuple string -> rawToken
return function (m) {
return { type: type, match: m[0] };
};
}
var ret = [
{ re: /^\s+/, f: f(" ") },
{ re: /^\{/, f: f("{") },
{ re: /^\}/, f: f("}") },
{ re: /^\[/, f: f("[") },
{ re: /^\]/, f: f("]") },
{ re: /^,/, f: f(",") },
{ re: /^:/, f: f(":") },
{ re: /^(?:true|false|null)/, f: fKeyword },
{ re: /^\-?\d+(?:\.\d+)?(?:[eE][+-]?\d+)?/, f: fNumber },
{ re: /^"(?:[^"\\]|\\["bnrtf\\\/]|\\u[0-9a-fA-F]{4})*"/, f: fStringDouble },
];
// additional stuff
if (relaxed) {
ret = ret.concat([
{ re: /^'((?:[^'\\]|\\['bnrtf\\\/]|\\u[0-9a-fA-F]{4})*)'/, f: fStringSingle },
{ re: /^\/\/.*?(?:\r\n|\r|\n)/, f: fComment },
{ re: /^\/\*[\s\S]*?\*\//, f: fComment },
{ re: /^[$a-zA-Z0-9_\-+\.\*\?!\|&%\^\/#\\]+/, f: fIdentifier },
]);
}
return ret;
}
var lexer = makeLexer(makeTokenSpecs(true));
var strictLexer = makeLexer(makeTokenSpecs(false));
// :: array token -> nat -> nat?
function previousNWSToken(tokens, index) {
for (; index >= 0; index--) {
if (tokens[index].type !== " ") {
return index;
}
}
return undefined;
}
// :: array token -> array token
function stripTrailingComma(tokens) {
var res = [];
tokens.forEach(function (token, index) {
if (index > 0 && (token.type === "]" || token.type === "}")) {
// go backwards as long as there is whitespace, until first comma
var commaI = previousNWSToken(res, index - 1);
if (commaI !== undefined && commaI > 0 && res[commaI].type === ",") {
var preCommaI = previousNWSToken(res, commaI - 1);
if (preCommaI !== undefined && res[preCommaI].type !== "[" && res[preCommaI].type !== "{") {
res[commaI] = {
type: " ",
match: " ",
value: " ",
line: tokens[commaI].line,
};
}
}
}
res.push(token);
});
return res;
}
// :: string -> string
function transform(text) {
// Tokenize contents
var tokens = lexer(text);
// remove trailing commas
tokens = stripTrailingComma(tokens);
// concat stuff
return tokens.reduce(function (str, token) {
return str + token.match;
}, "");
}
// typify: type parseWarning = { message: string, line: nat }
// typify: type parseState = { pos : nat, warnings: array parseWarning }
// :: array parseToken -> parseState -> *
function popToken(tokens, state) {
var token = tokens[state.pos];
state.pos += 1;
if (!token) {
var line = tokens.length !== 0 ? tokens[tokens.length - 1].line : 1;
return { type: "eof", match: "", line: line }; // XXX: match should be value
}
return token;
}
// :: token -> string
function strToken(token) {
switch (token.type) {
case "atom":
case "string":
case "number":
return token.type + " " + token.match;
case "eof":
return "end-of-file";
default:
return "'" + token.type + "'";
}
}
// :: array token -> parseState -> undefined
function skipColon(tokens, state) {
var colon = popToken(tokens, state);
if (colon.type !== ":") {
var message = "Unexpected token: " + strToken(colon) + ", expected ':'";
if (state.tolerant) {
state.warnings.push({
message: message,
line: colon.line,
});
state.pos -= 1;
} else {
var err = new SyntaxError(message);
err.line = colon.line;
throw err;
}
}
}
// :: array token -> parseState -> (array string)? -> token
function skipPunctuation(tokens, state, valid) {
var punctuation = [",", ":", "]", "}"];
var token = popToken(tokens, state);
while (true) { // eslint-disable-line no-constant-condition
if (valid && valid.indexOf(token.type) !== -1) {
return token;
} else if (token.type === "eof") {
return token;
} else if (punctuation.indexOf(token.type) !== -1) {
var message = "Unexpected token: " + strToken(token) + ", expected '[', '{', number, string or atom";
if (state.tolerant) {
state.warnings.push({
message: message,
line: token.line,
});
token = popToken(tokens, state);
} else {
var err = new SyntaxError(message);
err.line = token.line;
throw err;
}
} else {
return token;
}
}
}
// :: parseState -> token -> string -> undefined
function raiseError(state, token, message) {
if (state.tolerant) {
state.warnings.push({
message: message,
line: token.line,
});
} else {
var err = new SyntaxError(message);
err.line = token.line;
throw err;
}
}
// :: parseState -> token -> string -> undefined
function raiseUnexpected(state, token, expected) {
raiseError(state, token, "Unexpected token: " + strToken(token) + ", expected " + expected);
}
// :: parseState -> {} -> parseToken -> undefined
function checkDuplicates(state, obj, token) {
var key = token.value;
if (state.duplicate && Object.prototype.hasOwnProperty.call(obj, key)) {
raiseError(state, token, "Duplicate key: " + key);
}
}
// XXX: too loosy signature
// :: parseState -> any -> any -> any -> undefined
function appendPair(state, obj, key, value) {
value = state.reviver ? state.reviver(key, value) : value;
if (value !== undefined) {
obj[key] = value;
}
}
// :: array parseToken -> parseState -> map -> undefined
function parsePair(tokens, state, obj) {
var token = skipPunctuation(tokens, state, [":"]);
var key;
var value;
if (token.type !== "string") {
raiseUnexpected(state, token, "string");
switch (token.type) {
case ":":
token = {
type: "string",
value: "null",
line: token.line,
};
state.pos -= 1;
break;
case "number":
case "atom":
token = {
type: "string",
value: "" + token.value,
line: token.line,
};
break;
case "[":
case "{":
state.pos -= 1;
value = parseAny(tokens, state); // eslint-disable-line no-use-before-define
appendPair(state, obj, "null", value);
return;
// no default
}
}
checkDuplicates(state, obj, token);
key = token.value;
skipColon(tokens, state);
value = parseAny(tokens, state); // eslint-disable-line no-use-before-define
appendPair(state, obj, key, value);
}
// :: array parseToken -> parseState -> array -> undefined
function parseElement(tokens, state, arr) {
var key = arr.length;
var value = parseAny(tokens, state); // eslint-disable-line no-use-before-define
arr[key] = state.reviver ? state.reviver("" + key, value) : value;
}
// :: array parseToken -> parseState -> {}
function parseObject(tokens, state) {
return parseMany(tokens, state, {}, { // eslint-disable-line no-use-before-define
skip: [":", "}"],
elementParser: parsePair,
elementName: "string",
endSymbol: "}",
});
}
// :: array parseToken -> parseState -> array
function parseArray(tokens, state) {
return parseMany(tokens, state, [], { // eslint-disable-line no-use-before-define
skip: ["]"],
elementParser: parseElement,
elementName: "json object",
endSymbol: "]",
});
}
// typify: type parseManyOpts = { skip: array tokenType, elementParser: fn, elementName: string, endSymbol: tokenType }
// :: t : array | {} => array parseToken -> parseState -> t -> parseManyOpts -> t
function parseMany(tokens, state, obj, opts) {
var token = skipPunctuation(tokens, state, opts.skip);
if (token.type === "eof") {
raiseUnexpected(state, token, "'" + opts.endSymbol + "' or " + opts.elementName);
token = {
type: opts.endSymbol,
line: token.line,
};
}
switch (token.type) {
case opts.endSymbol:
return obj;
default:
state.pos -= 1; // push the token back
opts.elementParser(tokens, state, obj);
break;
}
// Rest
while (true) { // eslint-disable-line no-constant-condition
token = popToken(tokens, state);
if (token.type !== opts.endSymbol && token.type !== ",") {
raiseUnexpected(state, token, "',' or '" + opts.endSymbol + "'");
token = {
type: token.type === "eof" ? opts.endSymbol : ",",
line: token.line,
};
state.pos -= 1;
}
switch (token.type) {
case opts.endSymbol:
return obj;
case ",":
opts.elementParser(tokens, state, obj);
break;
// no default
}
}
}
// :: array parseToken -> parseState -> any -> undefined
function endChecks(tokens, state, ret) {
if (state.pos < tokens.length) {
raiseError(state, tokens[state.pos],
"Unexpected token: " + strToken(tokens[state.pos]) + ", expected end-of-input");
}
// Throw error at the end
if (state.tolerant && state.warnings.length !== 0) {
var message = state.warnings.length === 1 ? state.warnings[0].message : state.warnings.length + " parse warnings";
var err = new SyntaxError(message);
err.line = state.warnings[0].line;
err.warnings = state.warnings;
err.obj = ret;
throw err;
}
}
// :: array parseToken -> parseState -> boolean? -> any
function parseAny(tokens, state, end) {
var token = skipPunctuation(tokens, state);
var ret;
if (token.type === "eof") {
raiseUnexpected(state, token, "json object");
}
switch (token.type) {
case "{":
ret = parseObject(tokens, state);
break;
case "[":
ret = parseArray(tokens, state);
break;
case "string":
case "number":
case "atom":
ret = token.value;
break;
// no default
}
if (end) {
ret = state.reviver ? state.reviver("", ret) : ret;
endChecks(tokens, state, ret);
}
return ret;
}
// :: string -> * -> any
function parse(text, opts) {
if (typeof opts === "function" || opts === undefined) {
return JSON.parse(transform(text), opts);
} else if (new Object(opts) !== opts) { // eslint-disable-line no-new-object
throw new TypeError("opts/reviver should be undefined, a function or an object");
}
opts.relaxed = opts.relaxed !== undefined ? opts.relaxed : true;
opts.warnings = opts.warnings || opts.tolerant || false;
opts.tolerant = opts.tolerant || false;
opts.duplicate = opts.duplicate || false;
if (!opts.warnings && !opts.relaxed) {
return JSON.parse(text, opts.reviver);
}
var tokens = opts.relaxed ? lexer(text) : strictLexer(text);
if (opts.relaxed) {
// Strip commas
tokens = stripTrailingComma(tokens);
}
if (opts.warnings) {
// Strip whitespace
tokens = tokens.filter(function (token) {
return token.type !== " ";
});
var state = { pos: 0, reviver: opts.reviver, tolerant: opts.tolerant, duplicate: opts.duplicate, warnings: [] };
return parseAny(tokens, state, true);
} else {
var newtext = tokens.reduce(function (str, token) {
return str + token.match;
}, "");
return JSON.parse(newtext, opts.reviver);
}
}
// :: any -> string -> ... -> string
function stringifyPair(obj, key) {
return JSON.stringify(key) + ":" + stringify(obj[key]); // eslint-disable-line no-use-before-define
}
// :: any -> ... -> string
function stringify(obj) {
switch (typeof obj) {
case "string":
case "number":
case "boolean":
return JSON.stringify(obj);
// no default
}
if (Array.isArray(obj)) {
return "[" + obj.map(stringify).join(",") + "]";
}
if (new Object(obj) === obj) { // eslint-disable-line no-new-object
var keys = Object.keys(obj);
keys.sort();
return "{" + keys.map(stringifyPair.bind(null, obj)) + "}";
}
return "null";
}
// Export stuff
var RJSON = {
transform: transform,
parse: parse,
stringify: stringify,
};
/* global window, module */
if (typeof module !== "undefined") {
module.exports = RJSON;
} else if (typeof window !== "undefined") {
window.RJSON = RJSON;
}
}());