blocks|key|947866|text|如果eval抛出stackoverflow，您可以使用以下代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|947867|http://code.google.com/p/json-sans-eval/|offset|length|947868|一个根本不使用eval()的JSON解析器。|947869|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|14|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@$D|Q|E|R|1|S]]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|C]]]]

If eval throws stackoverflow, you can use this

<a href="http://code.google.com/p/json-sans-eval/" rel="nofollow noreferrer">http://code.google.com/p/json-sans-eval/</a>

A JSON parser that doesn't use eval() at all.

blocks|key|1161834|text|我建议您将JSON字符串分成块，并按需提供它们。可能也在使用AJAX，你可以有一个适合你需要的菜谱。使用“分而治之”机制，我认为您仍然可以使用常见的JSON解析方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1161835|希望这能有所帮助，|1161836|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I recommend you to divide JSON string in chunks, and bring them on demand. May be using AJAX too, you can have a recipe that just fit your needs.
Using a "divide and conquer" mechanism, I think you can still use common JSON parsing methods.

Hope that helps,

blocks|key|1161920|text|我已经编写了json解析器，它们不是用几种语言递归的，但到目前为止还不是用javascript写的。它不是递归的，而是使用一个名为stack的本地数组。在actionscript中，这比递归要快得多，内存效率也更高，我想javascript也应该是类似的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1161921|作为优化和简化，此实现仅对带反斜杠转义的带引号的字符串使用eval。它可以很容易地替换为来自任何其他解析器的字符串处理。转义处理代码很长，并且与递归无关。|offset|length|style|CODE|1161922|这个实现在(至少)以下方面是不严格的。它将8位字符视为空格。它允许数字中的前导"%2B“和"0”。它允许在数组和对象中尾随"，“。它忽略第一个结果之后的输入。所以"%2B09,2“返回9，忽略"2”。|1161923|function+parseJSON(+inJSON+)+{
++++var+result;
++++var+parent;
++++var+string;

++++var+depth+=+0;
++++var+stack+=+new+Array();
++++var+state+=+0;

++++var+began+,+place+=+0+,+limit+=+inJSON.length;
++++var+letter;

++++while+(+place+<+limit+)+{
++++++++letter+=+inJSON.charCodeAt(+place%2B%2B+);

++++++++if+(+letter+<=+0x20+%7C%7C+letter+>=+0x7F+)+{+++//++whitespace+or+control
++++++++}+else+if+(+letter+===+0x22+)+{+++++++++++++//++"+string
++++++++++++var+slash+=+0;
++++++++++++var+plain+=+true;

++++++++++++began+=+place+-+1;
++++++++++++while+(+place+<+limit+)+{
++++++++++++++++letter+=+inJSON.charCodeAt(+place%2B%2B+);

++++++++++++++++if+(+slash+!==+0+)+{
++++++++++++++++++++slash+=+0;
++++++++++++++++}+else+if+(+letter+===+0x5C+)+{+++++//++\+escape
++++++++++++++++++++slash+=+1;
++++++++++++++++++++plain+=+false;
++++++++++++++++}+else+if+(+letter+===+0x22+)+{+++++//++"+string
++++++++++++++++++++if+(+plain+)+{
++++++++++++++++++++++++result+=+inJSON.substring(+began+%2B+1+,+place+-+1+);
++++++++++++++++++++}+else+{
++++++++++++++++++++++++string+=+inJSON.substring(+began+,+place+);
++++++++++++++++++++++++result+=+eval(+string+);++++//++eval+to+unescape
++++++++++++++++++++}

++++++++++++++++++++break;
++++++++++++++++}
++++++++++++}
++++++++}+else+if+(+letter+===+0x7B+)+{+++++++++++++//++{+object
++++++++++++stack[depth%2B%2B]+=+state;
++++++++++++stack[depth%2B%2B]+=+parent;
++++++++++++parent+=+new+Object();
++++++++++++result+=+undefined;
++++++++++++state+=+letter;
++++++++}+else+if+(+letter+===+0x7D+)+{+++++++++++++//++}+object
++++++++++++if+(+state+===+0x3A+)+{
++++++++++++++++parent[stack[--depth]]+=+result;
++++++++++++++++state+=+stack[--depth];
++++++++++++}

++++++++++++if+(+state+===+0x7B+)+{
++++++++++++++++result+=+parent;
++++++++++++++++parent+=+stack[--depth];
++++++++++++++++state+=+stack[--depth];
++++++++++++}+else+{
++++++++++++++++//++error+got+}+expected+state+{
++++++++++++++++result+=+undefined;
++++++++++++++++break;
++++++++++++}
++++++++}+else+if+(+letter+===+0x5B+)+{+++++++++++++//++[+array
++++++++++++stack[depth%2B%2B]+=+state;
++++++++++++stack[depth%2B%2B]+=+parent;
++++++++++++parent+=+new+Array();
++++++++++++result+=+undefined;
++++++++++++state+=+letter;
++++++++}+else+if+(+letter+===+0x5D+)+{+++++++++++++//++]+array
++++++++++++if+(+state+===+0x5B+)+{
++++++++++++++++if+(+undefined+!==+result+)+parent.push(+result+);

++++++++++++++++result+=+parent;
++++++++++++++++parent+=+stack[--depth];
++++++++++++++++state+=+stack[--depth];
++++++++++++}+else+{
++++++++++++++++//++error+got+]+expected+state+[
++++++++++++++++result+=+undefined;
++++++++++++++++break;
++++++++++++}
++++++++}+else+if+(+letter+===+0x2C+)+{+++++++++++++//++,+delimiter
++++++++++++if+(+undefined+===+result+)+{
++++++++++++++++//++error+got+,+expected+previous+value
++++++++++++++++break;
++++++++++++}+else+if+(+state+===+0x3A+)+{
++++++++++++++++parent[stack[--depth]]+=+result;
++++++++++++++++state+=+stack[--depth];
++++++++++++++++result+=+undefined;
++++++++++++}+else+if+(+state+===+0x5B+)+{
++++++++++++++++parent.push(+result+);
++++++++++++++++result+=+undefined;
++++++++++++}+else+{
++++++++++++++++//++error+got+,+expected+state+[+or+:
++++++++++++++++result+=+undefined;
++++++++++++++++break;
++++++++++++}
++++++++}+else+if+(+letter+===+0x3A+)+{+++++++++++++//++:+assignment
++++++++++++if+(+state+===+0x7B+)+{
++++++++++++++++//++could+verify+result+is+string
++++++++++++++++stack[depth%2B%2B]+=+state;
++++++++++++++++stack[depth%2B%2B]+=+result;
++++++++++++++++state+=+letter;
++++++++++++++++result+=+undefined;
++++++++++++}+else+{
++++++++++++++++//++error+got+:+expected+state+{
++++++++++++++++result+=+undefined;
++++++++++++++++break;
++++++++++++}
++++++++}+else+{
++++++++++++if+(+(+letter+>=+0x30+&&+letter+<=+0x39+)+%7C%7C+letter+===+0x2B+%7C%7C+letter+===+0x2D+%7C%7C+letter+===+0x2E+)+{
++++++++++++++++var+++++++++++++exponent+=+-2;
++++++++++++++++var+++++++++++++real+=+(+letter+===+0x2E+);
++++++++++++++++var+++++++++++++digits+=+(+letter+>=+0x30+&&+letter+<=+0x39+)+?+1+:+0;

++++++++++++++++began+=+place+-+1;
++++++++++++++++while+(+place+<+limit+)+{
++++++++++++++++++++letter+=+inJSON.charCodeAt(+place%2B%2B+);

++++++++++++++++++++if+(+letter+>=+0x30+&&+letter+<=+0x39+)+{+++++++++++//++digit
++++++++++++++++++++++++digits+%2B=+1;
++++++++++++++++++++}+else+if+(+letter+===+0x2E+)+{+++++++++++++++++++++//++.
++++++++++++++++++++++++if+(+real+)+break;
++++++++++++++++++++++++else+real+=+true;
++++++++++++++++++++}+else+if+(+letter+===+0x45+%7C%7C+letter+===+0x65+)+{++//++e+E
++++++++++++++++++++++++if+(+exponent+>+began+%7C%7C+0+===+digits+)+break;
++++++++++++++++++++++++else+exponent+=+place+-+1;
++++++++++++++++++++++++real+=+true;
++++++++++++++++++++}+else+if+(+letter+===+0x2B+%7C%7C+letter+===+0x2D+)+{++//++%2B+-
++++++++++++++++++++++++if+(+place+!=+exponent+%2B+2+)+break;
++++++++++++++++++++}+else+{
++++++++++++++++++++++++break;
++++++++++++++++++++}
++++++++++++++++}

++++++++++++++++place+-=+1;
++++++++++++++++string+=+inJSON.substring(+began+,+place+);

++++++++++++++++if+(+0+===+digits+)+break;++//++error+expected+digits
++++++++++++++++if+(+real+)+result+=+parseFloat(+string+);
++++++++++++++++else+result+=+parseInt(+string+,+10+);
++++++++++++}+else+if+(+letter+===+0x6E+&&+'ull'+===+inJSON.substr(+place+,+3+)+)+{
++++++++++++++++result+=+null;
++++++++++++++++place+%2B=+3;
++++++++++++}+else+if+(+letter+===+0x74+&&+'rue'+===+inJSON.substr(+place+,+3+)+)+{
++++++++++++++++result+=+true;
++++++++++++++++place+%2B=+3;
++++++++++++}+else+if+(+letter+===+0x66+&&+'alse'+===+inJSON.substr(+place+,+4+)+)+{
++++++++++++++++result+=+false;
++++++++++++++++place+%2B=+4;
++++++++++++}+else+{
++++++++++++++++//++error+unrecognized+literal
++++++++++++++++result+=+undefined;
++++++++++++++++break;
++++++++++++}
++++++++}

++++++++if+(+0+===+depth+)+break;
++++}

++++return+result;
}|code-block|syntax|javascript|1161924|entityMap^0|0|T|4|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|U|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|V|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I have written json parsers that are not recursive in several languages, but until now not in javascript. Instead of being recursive, this uses a local array named stack. In actionscript this was substantially faster and more memory efficient than recursion, and I assume javascript would be similar.

This implementation uses <code>eval</code> only for quoted strings with backslash escapes, as both an optimization and simplification. That could easily be replaced with the string handling from any other parser. The escape handling code is long and not related to recursion.

This implementation is not strict in (at least) the following ways. It treats 8 bit characters as whitespace. It allows leading "+" and "0" in numbers. It allows trailing "," in arrays and objects. It ignores input after the first result. So "[+09,]2" returns [9] and ignores "2".

<pre><code>function parseJSON( inJSON ) {
 var result;
 var parent;
 var string;

 var depth = 0;
 var stack = new Array();
 var state = 0;

 var began , place = 0 , limit = inJSON.length;
 var letter;

 while ( place &lt; limit ) {
 letter = inJSON.charCodeAt( place++ );

 if ( letter &lt;= 0x20 || letter &gt;= 0x7F ) { // whitespace or control
 } else if ( letter === 0x22 ) { // " string
 var slash = 0;
 var plain = true;

 began = place - 1;
 while ( place &lt; limit ) {
 letter = inJSON.charCodeAt( place++ );

 if ( slash !== 0 ) {
 slash = 0;
 } else if ( letter === 0x5C ) { // \ escape
 slash = 1;
 plain = false;
 } else if ( letter === 0x22 ) { // " string
 if ( plain ) {
 result = inJSON.substring( began + 1 , place - 1 );
 } else {
 string = inJSON.substring( began , place );
 result = eval( string ); // eval to unescape
 }

 break;
 }
 }
 } else if ( letter === 0x7B ) { // { object
 stack[depth++] = state;
 stack[depth++] = parent;
 parent = new Object();
 result = undefined;
 state = letter;
 } else if ( letter === 0x7D ) { // } object
 if ( state === 0x3A ) {
 parent[stack[--depth]] = result;
 state = stack[--depth];
 }

 if ( state === 0x7B ) {
 result = parent;
 parent = stack[--depth];
 state = stack[--depth];
 } else {
 // error got } expected state {
 result = undefined;
 break;
 }
 } else if ( letter === 0x5B ) { // [ array
 stack[depth++] = state;
 stack[depth++] = parent;
 parent = new Array();
 result = undefined;
 state = letter;
 } else if ( letter === 0x5D ) { // ] array
 if ( state === 0x5B ) {
 if ( undefined !== result ) parent.push( result );

 result = parent;
 parent = stack[--depth];
 state = stack[--depth];
 } else {
 // error got ] expected state [
 result = undefined;
 break;
 }
 } else if ( letter === 0x2C ) { // , delimiter
 if ( undefined === result ) {
 // error got , expected previous value
 break;
 } else if ( state === 0x3A ) {
 parent[stack[--depth]] = result;
 state = stack[--depth];
 result = undefined;
 } else if ( state === 0x5B ) {
 parent.push( result );
 result = undefined;
 } else {
 // error got , expected state [ or :
 result = undefined;
 break;
 }
 } else if ( letter === 0x3A ) { // : assignment
 if ( state === 0x7B ) {
 // could verify result is string
 stack[depth++] = state;
 stack[depth++] = result;
 state = letter;
 result = undefined;
 } else {
 // error got : expected state {
 result = undefined;
 break;
 }
 } else {
 if ( ( letter &gt;= 0x30 &amp;&amp; letter &lt;= 0x39 ) || letter === 0x2B || letter === 0x2D || letter === 0x2E ) {
 var exponent = -2;
 var real = ( letter === 0x2E );
 var digits = ( letter &gt;= 0x30 &amp;&amp; letter &lt;= 0x39 ) ? 1 : 0;

 began = place - 1;
 while ( place &lt; limit ) {
 letter = inJSON.charCodeAt( place++ );

 if ( letter &gt;= 0x30 &amp;&amp; letter &lt;= 0x39 ) { // digit
 digits += 1;
 } else if ( letter === 0x2E ) { // .
 if ( real ) break;
 else real = true;
 } else if ( letter === 0x45 || letter === 0x65 ) { // e E
 if ( exponent &gt; began || 0 === digits ) break;
 else exponent = place - 1;
 real = true;
 } else if ( letter === 0x2B || letter === 0x2D ) { // + -
 if ( place != exponent + 2 ) break;
 } else {
 break;
 }
 }

 place -= 1;
 string = inJSON.substring( began , place );

 if ( 0 === digits ) break; // error expected digits
 if ( real ) result = parseFloat( string );
 else result = parseInt( string , 10 );
 } else if ( letter === 0x6E &amp;&amp; 'ull' === inJSON.substr( place , 3 ) ) {
 result = null;
 place += 3;
 } else if ( letter === 0x74 &amp;&amp; 'rue' === inJSON.substr( place , 3 ) ) {
 result = true;
 place += 3;
 } else if ( letter === 0x66 &amp;&amp; 'alse' === inJSON.substr( place , 4 ) ) {
 result = false;
 place += 4;
 } else {
 // error unrecognized literal
 result = undefined;
 break;
 }
 }

 if ( 0 === depth ) break;
 }

 return result;
}
</code></pre>

I have a very large JSON string that I need to parse with in-browser JavaScript. Right now, in a few browsers, I run out of stack space. Unfortunately, my JSON can contain user strings, so I can't use eval or otherwise let the browser parse it.

I've looked at a few of the standard JavaScript JSON parsers, and they are recursive. Wondering if anyone knows of any JSON parser that is safe and non-recursive. I'd be willing for it to have fewer features -- I just have a giant array of objects.

Alternatively, if someone knows of one that might be easy to modify, that would be a big help too.

EDIT: On closer inspection the stack overflow is thrown by eval() used inside the parser. So, it must be recursive.

non-recursive JavaScript JSON parser

JSON

我有一个非常大的JSON字符串，需要用浏览器中的JavaScript进行解析。现在，在一些浏览器中，我耗尽了堆栈空间。不幸的是，我的JSON可以包含用户字符串，所以我不能使用eval或者让浏览器解析它。我看过一些标准的JavaScript JSON解析器，它们是递归的。我想知道是否有人知道任何安全且非递归的JSON解析...

问非递归JavaScript JSON解析器
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