%PDF-
%PDF-
Mini Shell
Mini Shell
(function(context) {
var Lazy = context.Lazy;
if (typeof Lazy === 'undefined' && typeof require === 'function') {
Lazy = require('../lazy.js');
}
/**
* @constructor
*/
function JsonSequence(json) {
this.json = json;
};
JsonSequence.prototype = new Lazy.Sequence();
JsonSequence.prototype.getIterator = function() {
return new JsonIterator(this.json);
};
// Patterns
var NumberPattern = /^\d+(?:\.\d+)?$/,
BooleanPattern = /^(?:true|false)$/,
NullPattern = /^null$/;
/**
* @constructor
*/
function JsonIterator(json) {
this.json = json;
this.position = 0;
this.tokenMatcher = /[":,\[\]\{\}]|\d+(?:\.\d+)?|true|false|null|\b./g;
this.moveNext = this.firstMoveNext;
};
JsonIterator.prototype.current = function() {
return this.currentValue;
};
JsonIterator.prototype.firstMoveNext = function() {
this.expectToken('[');
return this.readValue();
};
JsonIterator.prototype.readValue = function() {
var match = this.tokenMatcher.exec(this.json);
if (!match) {
this.unexpectedEOS();
}
var token = match[0];
if (token === ']') {
return false;
}
this.position = match.index + token.length;
if (token === '"') {
this.currentValue = this.readString();
} else if (token === '[') {
this.currentValue = this.readArray();
} else if (token === '{') {
this.currentValue = this.readObject();
} else if (NumberPattern.test(token)) {
this.currentValue = Number(token);
} else if (NullPattern.test(token)) {
this.currentValue = null;
} else if (BooleanPattern.test(token)) {
this.currentValue = token === 'true';
} else {
this.unexpectedToken(match);
}
this.moveNext = this.readAnotherValue;
return true;
};
JsonIterator.prototype.readString = function(fromPosition) {
var json = this.json,
tokenMatcher = this.tokenMatcher,
position = typeof fromPosition === 'number' ? fromPosition : this.position,
match,
string;
while (match = tokenMatcher.exec(json)) {
if (match[0] === '"' && json.charAt(match.index - 1) !== '\\') {
return json.substring(position, match.index)
.replace(/\\(.)/g, '$1');
}
}
this.unexpectedEOS();
};
JsonIterator.prototype.readArray = function(fromPosition) {
var json = this.json,
tokenMatcher = this.tokenMatcher,
position = typeof fromPosition === 'number' ? fromPosition : this.position,
openBrackets = 1,
match,
string;
while ((openBrackets > 0) && (match = tokenMatcher.exec(json))) {
switch (match[0]) {
case '"':
this.readString(match.index + 1);
break;
case '[':
++openBrackets;
break;
case ']':
--openBrackets;
break;
}
}
if (openBrackets === 0) {
// For now we'll just be lazy (ba-dum, ching!) and use JSON.parse for arrays
// *within* the JSON.
return JSON.parse(json.substring(position - 1, match.index + 1));
}
this.unexpectedEOS();
};
JsonIterator.prototype.readObject = function() {
var json = this.json,
tokenMatcher = this.tokenMatcher,
openBraces = 1,
expecting = ['"', '}'],
state = 'key',
match,
string;
while ((openBraces > 0) && (match = tokenMatcher.exec(json))) {
if (expecting && !this.tokenIsExpected(match[0], expecting)) {
this.unexpectedToken(match, expecting);
}
switch (match[0]) {
case '"':
this.readString(match.index + 1);
expecting = state === 'key' ? ':' : [',', '}'];
break;
case '[':
this.readArray(match.index + 1);
expecting = [',', '}'];
break;
case ':':
state = 'value';
expecting = null;
break;
case ',':
state = 'key';
expecting = '"';
break;
case '{':
state = 'key';
expecting = '"';
++openBraces;
break;
case '}':
expecting = [',', '}'];
--openBraces;
break;
}
}
if (openBraces === 0) {
// For now we'll just be lazy (ba-dum, ching!) and use JSON.parse for
// objects *within* the JSON.
return JSON.parse(json.substring(this.position - 1, match.index + 1));
}
this.unexpectedEOS();
};
JsonIterator.prototype.readAnotherValue = function() {
var separator = this.expectToken([',', ']']);
if (separator === ']') {
return false;
}
return this.readValue();
};
JsonIterator.prototype.expectToken = function(expectation) {
var match = this.tokenMatcher.exec(this.json);
if (!match) {
this.unexpectedEOS();
}
var token = match[0];
if (!this.tokenIsExpected(token, expectation)) {
this.unexpectedToken(match, expectation);
}
return token;
};
JsonIterator.prototype.tokenIsExpected = function(token, expectation) {
if (typeof expectation === 'string') {
return token === expectation;
}
for (var i = 0; i < expectation.length; ++i) {
if (token === expectation[i]) {
return true;
}
}
return false;
};
JsonIterator.prototype.unexpectedToken = function(match, expectation) {
var errorMessage = typeof match === 'object' ?
'Unexpected token ' + match[0] + ' at ' + match.index :
'Unexpected token ' + match;
if (expectation) {
if (typeof expectation === 'string') {
expectation = [expectation];
}
errorMessage += ' (expected one of: ' + expectation.join(' ') + ')';
}
throw new SyntaxError(errorMessage);
};
JsonIterator.prototype.unexpectedEOS = function() {
throw new SyntaxError(
'Unexpected end of input: ' +
JSON.stringify(this.json.substring(this.position))
);
};
/**
* Parses a JSON array into a sequence.
*
* @param {string} json A string representing a JSON array.
* @return {Sequence} A sequence comprising the elements in the JSON array,
* which are parsed out lazily.
*
* @examples
* Lazy.parseJSON('foo').toArray() // throws
* Lazy.parseJSON('[1, 2, 3]') // sequence: [1, 2, 3]
* Lazy.parseJSON('["foo", "bar"]') // sequence: ['foo', 'bar']
* Lazy.parseJSON('["foo", 1, "bar", 123]') // sequence: ['foo', 1, 'bar', 123]
* Lazy.parseJSON('[3.14, "foo"]') // sequence: [3.14, 'foo']
* Lazy.parseJSON('[1, "foo, \\"bar\\", baz"]') // sequence: [1, 'foo, "bar", baz']
* Lazy.parseJSON('[1, null, true, false]') // sequence: [1, null, true, false]
* Lazy.parseJSON('[1, [2, 3]]') // sequence: [1, [2, 3]]
* Lazy.parseJSON('[1, ["foo [1, 2] bar"]]') // sequence: [1, ["foo [1, 2] bar"]]
* Lazy.parseJSON('[1, [2, [3, 4]]]') // sequence: [1, [2, [3, 4]]]
* Lazy.parseJSON('[1, [2, 3], 4').toArray() // throws
* Lazy.parseJSON('[1, [2, 3], blah]').toArray() // throws
* Lazy.parseJSON('[1, [2, 3], blah').take(2) // sequence: [1, [2, 3]]
* Lazy.parseJSON('[1, { "foo": "bar" }]') // sequence: [1, { foo: 'bar' }]
* Lazy.parseJSON('[1, {}]') // sequence: [1, {}]
* Lazy.parseJSON('[1, {}}]').toArray() // throws
*
* // crazy example
* Lazy.parseJSON('[1, { "foo": { "bar": [1, null, ["baz"]] } }, [3, false]]') // sequence: [1, { foo: { 'bar': [1, null, ['baz']] } }, [3, false]]
*/
Lazy.parseJSON = function(json) {
return new JsonSequence(json);
};
if (typeof module === 'object' && module && module.exports) {
module.exports = Lazy;
}
}(typeof global !== 'undefined' ? global : this));
Zerion Mini Shell 1.0