mirror of
https://github.com/donl/JSON-js.git
synced 2026-05-26 06:12:13 -06:00
405 lines
13 KiB
JavaScript
405 lines
13 KiB
JavaScript
/*
|
|
json_parse_state.js
|
|
2016-05-02
|
|
|
|
Public Domain.
|
|
|
|
NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
|
|
|
|
This file creates a json_parse function.
|
|
|
|
json_parse(text, reviver)
|
|
This method parses a JSON text to produce an object or array.
|
|
It can throw a SyntaxError exception.
|
|
|
|
The optional reviver parameter is a function that can filter and
|
|
transform the results. It receives each of the keys and values,
|
|
and its return value is used instead of the original value.
|
|
If it returns what it received, then the structure is not modified.
|
|
If it returns undefined then the member is deleted.
|
|
|
|
Example:
|
|
|
|
// Parse the text. Values that look like ISO date strings will
|
|
// be converted to Date objects.
|
|
|
|
myData = json_parse(text, function (key, value) {
|
|
var a;
|
|
if (typeof value === "string") {
|
|
a =
|
|
/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/.exec(value);
|
|
if (a) {
|
|
return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4],
|
|
+a[5], +a[6]));
|
|
}
|
|
}
|
|
return value;
|
|
});
|
|
|
|
This is a reference implementation. You are free to copy, modify, or
|
|
redistribute.
|
|
|
|
This code should be minified before deployment.
|
|
See http://javascript.crockford.com/jsmin.html
|
|
|
|
USE YOUR OWN COPY. IT IS EXTREMELY UNWISE TO LOAD CODE FROM SERVERS YOU DO
|
|
NOT CONTROL.
|
|
*/
|
|
|
|
/*jslint for */
|
|
|
|
/*property
|
|
acomma, avalue, b, call, colon, container, exec, f, false, firstavalue,
|
|
firstokey, fromCharCode, go, hasOwnProperty, key, length, n, null, ocomma,
|
|
okey, ovalue, pop, prototype, push, r, replace, slice, state, t, test,
|
|
true
|
|
*/
|
|
|
|
var json_parse = (function () {
|
|
"use strict";
|
|
|
|
// This function creates a JSON parse function that uses a state machine rather
|
|
// than the dangerous eval function to parse a JSON text.
|
|
|
|
var state; // The state of the parser, one of
|
|
// 'go' The starting state
|
|
// 'ok' The final, accepting state
|
|
// 'firstokey' Ready for the first key of the object or
|
|
// the closing of an empty object
|
|
// 'okey' Ready for the next key of the object
|
|
// 'colon' Ready for the colon
|
|
// 'ovalue' Ready for the value half of a key/value pair
|
|
// 'ocomma' Ready for a comma or closing }
|
|
// 'firstavalue' Ready for the first value of an array or
|
|
// an empty array
|
|
// 'avalue' Ready for the next value of an array
|
|
// 'acomma' Ready for a comma or closing ]
|
|
var stack; // The stack, for controlling nesting.
|
|
var container; // The current container object or array
|
|
var key; // The current key
|
|
var value; // The current value
|
|
var escapes = { // Escapement translation table
|
|
"\\": "\\",
|
|
"\"": "\"",
|
|
"/": "/",
|
|
"t": "\t",
|
|
"n": "\n",
|
|
"r": "\r",
|
|
"f": "\f",
|
|
"b": "\b"
|
|
};
|
|
var string = { // The actions for string tokens
|
|
go: function () {
|
|
state = "ok";
|
|
},
|
|
firstokey: function () {
|
|
key = value;
|
|
state = "colon";
|
|
},
|
|
okey: function () {
|
|
key = value;
|
|
state = "colon";
|
|
},
|
|
ovalue: function () {
|
|
state = "ocomma";
|
|
},
|
|
firstavalue: function () {
|
|
state = "acomma";
|
|
},
|
|
avalue: function () {
|
|
state = "acomma";
|
|
}
|
|
};
|
|
var number = { // The actions for number tokens
|
|
go: function () {
|
|
state = "ok";
|
|
},
|
|
ovalue: function () {
|
|
state = "ocomma";
|
|
},
|
|
firstavalue: function () {
|
|
state = "acomma";
|
|
},
|
|
avalue: function () {
|
|
state = "acomma";
|
|
}
|
|
};
|
|
var action = {
|
|
|
|
// The action table describes the behavior of the machine. It contains an
|
|
// object for each token. Each object contains a method that is called when
|
|
// a token is matched in a state. An object will lack a method for illegal
|
|
// states.
|
|
|
|
"{": {
|
|
go: function () {
|
|
stack.push({state: "ok"});
|
|
container = {};
|
|
state = "firstokey";
|
|
},
|
|
ovalue: function () {
|
|
stack.push({container: container, state: "ocomma", key: key});
|
|
container = {};
|
|
state = "firstokey";
|
|
},
|
|
firstavalue: function () {
|
|
stack.push({container: container, state: "acomma"});
|
|
container = {};
|
|
state = "firstokey";
|
|
},
|
|
avalue: function () {
|
|
stack.push({container: container, state: "acomma"});
|
|
container = {};
|
|
state = "firstokey";
|
|
}
|
|
},
|
|
"}": {
|
|
firstokey: function () {
|
|
var pop = stack.pop();
|
|
value = container;
|
|
container = pop.container;
|
|
key = pop.key;
|
|
state = pop.state;
|
|
},
|
|
ocomma: function () {
|
|
var pop = stack.pop();
|
|
container[key] = value;
|
|
value = container;
|
|
container = pop.container;
|
|
key = pop.key;
|
|
state = pop.state;
|
|
}
|
|
},
|
|
"[": {
|
|
go: function () {
|
|
stack.push({state: "ok"});
|
|
container = [];
|
|
state = "firstavalue";
|
|
},
|
|
ovalue: function () {
|
|
stack.push({container: container, state: "ocomma", key: key});
|
|
container = [];
|
|
state = "firstavalue";
|
|
},
|
|
firstavalue: function () {
|
|
stack.push({container: container, state: "acomma"});
|
|
container = [];
|
|
state = "firstavalue";
|
|
},
|
|
avalue: function () {
|
|
stack.push({container: container, state: "acomma"});
|
|
container = [];
|
|
state = "firstavalue";
|
|
}
|
|
},
|
|
"]": {
|
|
firstavalue: function () {
|
|
var pop = stack.pop();
|
|
value = container;
|
|
container = pop.container;
|
|
key = pop.key;
|
|
state = pop.state;
|
|
},
|
|
acomma: function () {
|
|
var pop = stack.pop();
|
|
container.push(value);
|
|
value = container;
|
|
container = pop.container;
|
|
key = pop.key;
|
|
state = pop.state;
|
|
}
|
|
},
|
|
":": {
|
|
colon: function () {
|
|
if (Object.hasOwnProperty.call(container, key)) {
|
|
throw new SyntaxError("Duplicate key '" + key + "\"");
|
|
}
|
|
state = "ovalue";
|
|
}
|
|
},
|
|
",": {
|
|
ocomma: function () {
|
|
container[key] = value;
|
|
state = "okey";
|
|
},
|
|
acomma: function () {
|
|
container.push(value);
|
|
state = "avalue";
|
|
}
|
|
},
|
|
"true": {
|
|
go: function () {
|
|
value = true;
|
|
state = "ok";
|
|
},
|
|
ovalue: function () {
|
|
value = true;
|
|
state = "ocomma";
|
|
},
|
|
firstavalue: function () {
|
|
value = true;
|
|
state = "acomma";
|
|
},
|
|
avalue: function () {
|
|
value = true;
|
|
state = "acomma";
|
|
}
|
|
},
|
|
"false": {
|
|
go: function () {
|
|
value = false;
|
|
state = "ok";
|
|
},
|
|
ovalue: function () {
|
|
value = false;
|
|
state = "ocomma";
|
|
},
|
|
firstavalue: function () {
|
|
value = false;
|
|
state = "acomma";
|
|
},
|
|
avalue: function () {
|
|
value = false;
|
|
state = "acomma";
|
|
}
|
|
},
|
|
"null": {
|
|
go: function () {
|
|
value = null;
|
|
state = "ok";
|
|
},
|
|
ovalue: function () {
|
|
value = null;
|
|
state = "ocomma";
|
|
},
|
|
firstavalue: function () {
|
|
value = null;
|
|
state = "acomma";
|
|
},
|
|
avalue: function () {
|
|
value = null;
|
|
state = "acomma";
|
|
}
|
|
}
|
|
};
|
|
|
|
function debackslashify(text) {
|
|
|
|
// Remove and replace any backslash escapement.
|
|
|
|
return text.replace(/\\(?:u(.{4})|([^u]))/g, function (ignore, b, c) {
|
|
return b
|
|
? String.fromCharCode(parseInt(b, 16))
|
|
: escapes[c];
|
|
});
|
|
}
|
|
|
|
return function (source, reviver) {
|
|
|
|
// A regular expression is used to extract tokens from the JSON text.
|
|
// The extraction process is cautious.
|
|
|
|
var result;
|
|
var tx = /^[\u0020\t\n\r]*(?:([,:\[\]{}]|true|false|null)|(-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)|"((?:[^\r\n\t\\\"]|\\(?:["\\\/trnfb]|u[0-9a-fA-F]{4}))*)")/;
|
|
|
|
// Set the starting state.
|
|
|
|
state = "go";
|
|
|
|
// The stack records the container, key, and state for each object or array
|
|
// that contains another object or array while processing nested structures.
|
|
|
|
stack = [];
|
|
|
|
// If any error occurs, we will catch it and ultimately throw a syntax error.
|
|
|
|
try {
|
|
|
|
// For each token...
|
|
|
|
while (true) {
|
|
result = tx.exec(source);
|
|
if (!result) {
|
|
break;
|
|
}
|
|
|
|
// result is the result array from matching the tokenizing regular expression.
|
|
// result[0] contains everything that matched, including any initial whitespace.
|
|
// result[1] contains any punctuation that was matched, or true, false, or null.
|
|
// result[2] contains a matched number, still in string form.
|
|
// result[3] contains a matched string, without quotes but with escapement.
|
|
|
|
if (result[1]) {
|
|
|
|
// Token: Execute the action for this state and token.
|
|
|
|
action[result[1]][state]();
|
|
|
|
} else if (result[2]) {
|
|
|
|
// Number token: Convert the number string into a number value and execute
|
|
// the action for this state and number.
|
|
|
|
value = +result[2];
|
|
number[state]();
|
|
} else {
|
|
|
|
// String token: Replace the escapement sequences and execute the action for
|
|
// this state and string.
|
|
|
|
value = debackslashify(result[3]);
|
|
string[state]();
|
|
}
|
|
|
|
// Remove the token from the string. The loop will continue as long as there
|
|
// are tokens. This is a slow process, but it allows the use of ^ matching,
|
|
// which assures that no illegal tokens slip through.
|
|
|
|
source = source.slice(result[0].length);
|
|
}
|
|
|
|
// If we find a state/token combination that is illegal, then the action will
|
|
// cause an error. We handle the error by simply changing the state.
|
|
|
|
} catch (e) {
|
|
state = e;
|
|
}
|
|
|
|
// The parsing is finished. If we are not in the final "ok" state, or if the
|
|
// remaining source contains anything except whitespace, then we did not have
|
|
//a well-formed JSON text.
|
|
|
|
if (state !== "ok" || (/[^\u0020\t\n\r]/.test(source))) {
|
|
throw (state instanceof SyntaxError)
|
|
? state
|
|
: new SyntaxError("JSON");
|
|
}
|
|
|
|
// 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 current
|
|
// value in an empty key. If there is not a reviver function, we simply return
|
|
// that value.
|
|
|
|
return (typeof reviver === "function")
|
|
? (function walk(holder, key) {
|
|
var k;
|
|
var v;
|
|
var val = holder[key];
|
|
if (val && typeof val === "object") {
|
|
for (k in value) {
|
|
if (Object.prototype.hasOwnProperty.call(val, k)) {
|
|
v = walk(val, k);
|
|
if (v !== undefined) {
|
|
val[k] = v;
|
|
} else {
|
|
delete val[k];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return reviver.call(holder, key, val);
|
|
}({"": value}, ""))
|
|
: value;
|
|
};
|
|
}());
|