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BonsaiDen/bison.js

Created January 13, 2012 14:00
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Some fixes
Raw
bison.js
/**
* Copyright (c) 2009-2011 Ivo Wetzel.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
(function(undefined) {
/*
xxx: group
0: bool / null
xx: type
0 = false
1 = true
2 = null
1: int
2: float
3: string
4: array
5: object
6: close
7: end
*/
var BitStream = (function() {
// Some Lookup tables
var chrTable = new Array(255);
for(var i = 0; i < 256; i++) {
chrTable[i] = String.fromCharCode(i);
}
var maskTable = new Array(8),
powTable = new Array(8);
for(var i = 0; i < 9; i++) {
maskTable[i] = ~((powTable[i] = Math.pow(2, i) - 1) ^ 0xFF);
}
var stream = '',
value = 0,
left = 8,
index = 0,
max = 0;
return {
open: function(data) {
left = 8;
if (data !== undefined) {
max = data.length;
index = 0;
stream = data;
value = stream.charCodeAt(index);
} else {
value = 0;
stream = '';
}
},
close: function() {
if (value > 0) {
stream += chrTable[value];
}
return stream;
},
writeRaw: function(raw) {
if (left !== 8) {
stream += chrTable[value];
value = 0;
left = 8;
}
stream += raw;
},
readRaw: function(count) {
if (left !== 8) {
index++;
value = 0;
left = 8;
}
var data = stream.substr(index, count);
index += count;
value = stream.charCodeAt(index);
return data;
},
write: function write(val, count) {
var overflow = count - left,
use = left < count ? left : count,
shift = left - use;
if (overflow > 0) {
value += val >> overflow << shift;
} else {
value += val << shift;
}
left -= use;
if (left === 0) {
stream += chrTable[value];
left = 8;
value = 0;
if (overflow > 0) {
write(val & powTable[overflow], overflow);
}
}
},
read: function read(count) {
if (index >= max) {
return null;
}
var overflow = count - left,
use = left < count ? left : count,
shift = left - use;
var val = (value & maskTable[left]) >> shift;
left -= use;
if (left === 0) {
value = stream.charCodeAt(++index);
left = 8;
if (overflow > 0) {
val = val << overflow | read(overflow);
}
}
return val;
}
};
})();
// Shorthands
var write = BitStream.write,
read = BitStream.read,
writeRaw = BitStream.writeRaw,
readRaw = BitStream.readRaw,
open = BitStream.open,
close = BitStream.close;
// Encoder ----------------------------------------------------------------
function __encode(value) {
// Numbers
if (typeof value === 'number') {
var type = value !== (value | 0),
sign = 0;
if (value < 0) {
value = -value;
sign = 1;
}
write(1 + type, 3);
// Float
if (type) {
var shift = 1,
step = 10;
while(step <= value) {
shift++;
step *= 10;
}
// Ensure we don't lose precisiobn
shift = (8 - shift) + 1;
value = Math.round(value * (1000000000 / step));
// Figure out the smallest exp for value
while(value / 10 === ((value / 10) | 0)) {
value /= 10;
shift--;
}
}
// 2 size 0-3: 0 = < 16 1 = < 256 2 = < 65536 3 >
if (value < 2) {
write(0, 3);
write(value, 1);
} else if (value < 16) {
write(1, 3);
write(value, 4);
} else if (value < 256) {
write(2, 3);
write(value, 8);
} else if (value < 4096) {
write(3, 3);
write(value >> 8 & 0xff, 4);
write(value & 0xff, 8);
} else if (value < 65536) {
write(4, 3);
write(value >> 8 & 0xff, 8);
write(value & 0xff, 8);
} else if (value < 1048576) {
write(5, 3);
write(value >> 16 & 0xff, 4);
write(value >> 8 & 0xff, 8);
write(value & 0xff, 8);
} else if (value < 16777216) {
write(6, 3);
write(value >> 16 & 0xff, 8);
write(value >> 8 & 0xff, 8);
write(value & 0xff, 8);
} else {
write(7, 3);
write(value >> 24 & 0xff, 8);
write(value >> 16 & 0xff, 8);
write(value >> 8 & 0xff, 8);
write(value & 0xff, 8);
}
write(sign, 1);
if (type) {
write(shift, 4);
}
// Strings
} else if (typeof value === 'string') {
var l = value.length;
write(3, 3);
if (l > 65535) {
write(31, 5);
write(l >> 24 & 0xff, 8);
write(l >> 16 & 0xff, 8);
write(l >> 8 & 0xff, 8);
write(l & 0xff, 8);
} else if (l > 255) {
write(30, 5);
write(l >> 8 & 0xff, 8);
write(l & 0xff, 8);
} else if (l > 28) {
write(29, 5);
write(l, 8);
} else {
write(l, 5);
}
writeRaw(value);
// Booleans
} else if (typeof value === 'boolean') {
write(0, 3);
write(+value, 2);
// Null
} else if (value === null) {
write(0, 3);
write(2, 2);
// Arrays
} else if (value instanceof Array) {
write(4, 3);
for(var i = 0, l = value.length; i < l; i++) {
__encode(value[i]);
}
write(6, 3);
// Object
} else {
write(5, 3);
for(var e in value) {
__encode(e);
__encode(value[e]);
}
write(6, 3);
}
}
function encode(value) {
open();
__encode(value);
write(7, 3);
return close();
}
// Decoder ----------------------------------------------------------------
function decode(string) {
var pos = 0, l = string.length,
stack = [], i = -1,
type, top, value, obj,
// Objects
getKey = false, key, isObj, decoded;
open(string);
while((type = read(3)) !== 7) {
// Null
if (type === 0) {
value = read(2);
if (value === 2) {
value = null;
} else {
value = !!value;
}
// Integer / Float
} else if (type === 1 || type === 2) {
switch(read(3)) {
case 0:
value = read(1);
break;
case 1:
value = read(4);
break;
case 2:
value = read(8);
break;
case 3:
value = (read(4) << 8)
+ read(8);
break;
case 4:
value = (read(8) << 8)
+ read(8);
break;
case 5:
value = (read(4) << 16)
+ (read(8) << 8)
+ read(8);
break;
case 6:
value = (read(8) << 16)
+ (read(8) << 8)
+ read(8);
break;
case 7:
value = (read(8) << 24)
+ (read(8) << 16)
+ (read(8) << 8)
+ read(8);
break;
}
if (read(1)) {
value = -value;
}
if (type === 2) {
value /= Math.pow(10, read(4));
}
// String
} else if (type === 3) {
var size = read(5);
switch(size) {
case 31:
size = (read(8) << 24)
+ (read(8) << 16)
+ (read(8) << 8)
+ read(8);
break;
case 30:
size = (read(8) << 8)
+ read(8);
break;
case 29:
size = read(8);
break;
}
value = readRaw(size);
if (getKey) {
key = value;
getKey = false;
continue;
}
// Open Array / Objects
} else if (type === 4 || type === 5) {
getKey = type === 5;
value = getKey ? {} : [];
if (decoded === undefined) {
decoded = value;
} else {
if (isObj) {
top[key] = value;
} else {
top.push(value);
}
}
top = stack[++i] = value;
isObj = !(top instanceof Array);
continue;
// Close Array / Object
} else if (type === 6) {
top = stack[--i];
getKey = isObj = !(top instanceof Array);
continue;
}
// Assign value to top of stack or return value
if (isObj) {
top[key] = value;
getKey = true;
} else if (top !== undefined) {
top.push(value);
} else {
return value;
}
}
return decoded;
}
if (typeof window === 'undefined') {
exports.encode = encode;
exports.decode = decode;
} else {
window.BISON = {
encode: encode,
decode: decode
};
}
})();
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