Best comparison I’ve seen on the subject: http://www.raywenderlich.com/553/how-to-chose-the-best-xml-parser-for-your-iphone-project The difference between the slowest and fastest parsers in his case was a factor of 2. Depending on your feature requirements, there are definitely parsers that can cut your parsing time in half.
for(;;) { } functionally means while (true) { } It will probably break the loop/ return from loop based on some condition inside the loop body. The reason that for(;;) loops forever is because for has three parts, each of which is optional. The first part initializes the loop; the second decides whether or not … Read more
It depends on how complex the language you’re dealing with is. Splitting This is great when it works, but only works when there are no escaping conventions. It does not work for CSV for example because commas inside quoted strings are not proper split points. foo,bar,baz can be split, but foo,”bar,baz” cannot. Regular Regular expressions … Read more
According to the specification, a DecimalLiteral is defined as: DecimalLiteral :: DecimalIntegerLiteral . DecimalDigitsopt ExponentPartopt . DecimalDigits ExponentPartopt DecimalIntegerLiteral ExponentPartopt and for satisfying the parseFloat argument: Let inputString be ToString(string). Let trimmedString be a substring of inputString consisting of the leftmost character that is not a StrWhiteSpaceChar and all characters to the right of that … Read more
Assembler 427 bytes Obfuscated, assembled with the excellent A86 into a .com executable: dd 0db9b1f89h, 081bee3h, 0e8af789h, 0d9080080h, 0bdac7674h, 013b40286h dd 07400463ah, 0ccfe4508h, 08ce9f675h, 02fc8000h, 013b0057eh, 0feaac42ah dd 0bedf75c9h, 0ba680081h, 04de801h, 04874f73bh, 04474103ch, 0e8e8b60fh dd 08e8a003fh, 0e880290h, 0de0153h, 08b57e6ebh, 0d902a93eh, 046d891dh dd 08906c783h, 05f02a93eh, 03cffcee8h, 057197510h, 02a93e8bh, 08b06ef83h dd 05d9046dh, 02a93e89h, 03bc9d95fh, 0ac0174f7h, 074f73bc3h, 0f3cac24h … Read more
The two are intended for different purposes. The ToString method of any object is supposed to return a string representation of that object. Casting is quite different, and the ‘as’ key word performs a conditional cast, as has been said. The ‘as’ key word basically says “get me a reference of this type to that … Read more
A tokenizer breaks a stream of text into tokens, usually by looking for whitespace (tabs, spaces, new lines). A lexer is basically a tokenizer, but it usually attaches extra context to the tokens — this token is a number, that token is a string literal, this other token is an equality operator. A parser takes … Read more
Use the JSONObject // Get some JSON from wherever String json = getJSONFromServer(); // Parse the JSON response into an object JSONObject object = new JSONObject(json); // Get the results array JSONArray users = object.getJSONArray(“results”); for(int i = 0; i < users.length(); i++) { // Each element in the results array is a JSONObject with … Read more
The problem is that feed is not a NSArray, but a NSDictionary. Looking at the JSON, you likely want to access this array: [feed objectForKey:@”entry”]
Valid expressions can be validated with a regular expression, aside from parenthesis mismatching. (Mismatched parentheses will be caught by the shunting-yard algorithm as indicated in the wikipedia page, so I’m ignoring those.) The regular expression is as follows: PRE* OP POST* (INF PRE* OP POST*)* where: PRE is a prefix operator or ( POST is … Read more