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

95 lines
2.6 KiB

2 years ago
/*! (c) 2020 Andrea Giammarchi */
const {parse: $parse, stringify: $stringify} = JSON;
const {keys} = Object;
const Primitive = String; // it could be Number
const primitive = 'string'; // it could be 'number'
const ignore = {};
const object = 'object';
const noop = (_, value) => value;
const primitives = value => (
value instanceof Primitive ? Primitive(value) : value
);
const Primitives = (_, value) => (
typeof value === primitive ? new Primitive(value) : value
);
const revive = (input, parsed, output, $) => {
const lazy = [];
for (let ke = keys(output), {length} = ke, y = 0; y < length; y++) {
const k = ke[y];
const value = output[k];
if (value instanceof Primitive) {
const tmp = input[value];
if (typeof tmp === object && !parsed.has(tmp)) {
parsed.add(tmp);
output[k] = ignore;
lazy.push({k, a: [input, parsed, tmp, $]});
}
else
output[k] = $.call(output, k, tmp);
}
else if (output[k] !== ignore)
output[k] = $.call(output, k, value);
}
for (let {length} = lazy, i = 0; i < length; i++) {
const {k, a} = lazy[i];
output[k] = $.call(output, k, revive.apply(null, a));
}
return output;
};
const set = (known, input, value) => {
const index = Primitive(input.push(value) - 1);
known.set(value, index);
return index;
};
export const parse = (text, reviver) => {
const input = $parse(text, Primitives).map(primitives);
const value = input[0];
const $ = reviver || noop;
const tmp = typeof value === object && value ?
revive(input, new Set, value, $) :
value;
return $.call({'': tmp}, '', tmp);
};
export const stringify = (value, replacer, space) => {
const $ = replacer && typeof replacer === object ?
(k, v) => (k === '' || -1 < replacer.indexOf(k) ? v : void 0) :
(replacer || noop);
const known = new Map;
const input = [];
const output = [];
let i = +set(known, input, $.call({'': value}, '', value));
let firstRun = !i;
while (i < input.length) {
firstRun = true;
output[i] = $stringify(input[i++], replace, space);
}
return '[' + output.join(',') + ']';
function replace(key, value) {
if (firstRun) {
firstRun = !firstRun;
return value;
}
const after = $.call(this, key, value);
switch (typeof after) {
case object:
if (after === null) return after;
case primitive:
return known.get(after) || set(known, input, after);
}
return after;
}
};
export const toJSON = any => $parse(stringify(any));
export const fromJSON = any => parse($stringify(any));