Difference between revisions of "String (API)"
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− | + | The string API is a default Lua 5.1 API as defined [http://www.lua.org/manual/5.1/manual.html#5.4 here]. Please list any non-working functions below. | |
+ | |||
+ | ==Non-Working Functions== | ||
+ | |||
+ | ===string.gmatch(string, pattern)=== | ||
+ | |||
+ | Using any quantifier other than + will cause it to hang if that quantifier applies to the whole pattern and that pattern does not match the whole string. | ||
+ | |||
+ | Examples: | ||
+ | <pre> | ||
+ | "abcdef":gmatch("%a*") -- Works | ||
+ | "abc=def":gmatch("%a*") -- Hang | ||
+ | "abc=def":gmatch("%a.*") -- Works | ||
+ | "abc=def":gmatch("[%a.]*") -- Hang | ||
+ | "abc=def":gmatch("[^=]*") -- Hang | ||
+ | "abc=def":gmatch("([^=]*)=?") -- Works (Note: This produces the same result as the above pattern should) | ||
+ | "abcdef":gmatch("[^=]*") -- Works | ||
+ | "abc=def":gmatch("[^=]*=") -- Works | ||
+ | </pre> | ||
+ | |||
+ | ===string.sub / string.find === | ||
+ | |||
+ | Both string.sub and string.find work on their own, but calling string.find on a string returned by string.sub will return the index of the character in the original string, not the sub string you are referencing. | ||
+ | |||
+ | Example: | ||
+ | <pre> | ||
+ | local testString = "This is a sample string"; | ||
+ | local testSubString = string.sub(testString,5); | ||
+ | |||
+ | local indexOfSample = string.find(testSubString,"sample"); | ||
+ | </pre> | ||
+ | |||
+ | indexOfSample is returned 11 instead of the expected 7 | ||
+ | |||
+ | Concatenating a blank string onto the end of the string causes new memory to be allocated and works properly again | ||
+ | |||
+ | <pre> | ||
+ | local testString = "This is a sample string"; | ||
+ | local testSubString = string.sub(testString,5); | ||
+ | |||
+ | local indexOfSample = string.find(testSubString.."","sample"); | ||
+ | </pre> | ||
+ | |||
+ | This is also a problem with using string.find on command line arguments, as this returns the index in the full command path instead of the specific argument. | ||
+ | |||
+ | |||
+ | [[Category:APIs]] |
Latest revision as of 03:24, 7 December 2012
The string API is a default Lua 5.1 API as defined here. Please list any non-working functions below.
Non-Working Functions
string.gmatch(string, pattern)
Using any quantifier other than + will cause it to hang if that quantifier applies to the whole pattern and that pattern does not match the whole string.
Examples:
"abcdef":gmatch("%a*") -- Works "abc=def":gmatch("%a*") -- Hang "abc=def":gmatch("%a.*") -- Works "abc=def":gmatch("[%a.]*") -- Hang "abc=def":gmatch("[^=]*") -- Hang "abc=def":gmatch("([^=]*)=?") -- Works (Note: This produces the same result as the above pattern should) "abcdef":gmatch("[^=]*") -- Works "abc=def":gmatch("[^=]*=") -- Works
string.sub / string.find
Both string.sub and string.find work on their own, but calling string.find on a string returned by string.sub will return the index of the character in the original string, not the sub string you are referencing.
Example:
local testString = "This is a sample string"; local testSubString = string.sub(testString,5); local indexOfSample = string.find(testSubString,"sample");
indexOfSample is returned 11 instead of the expected 7
Concatenating a blank string onto the end of the string causes new memory to be allocated and works properly again
local testString = "This is a sample string"; local testSubString = string.sub(testString,5); local indexOfSample = string.find(testSubString.."","sample");
This is also a problem with using string.find on command line arguments, as this returns the index in the full command path instead of the specific argument.