Difference between revisions of "LlSubStringIndex"
m (clarify to concise & calculates & clever from clear and tests and arcane -- courtesy reasoning by analogy with hex) |
m (lsl code tagging) |
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| Line 13: | Line 13: | ||
|constants | |constants | ||
|examples=Matching against last names: | |examples=Matching against last names: | ||
< | <lsl> | ||
default | default | ||
{ | { | ||
| Line 33: | Line 33: | ||
} | } | ||
} | } | ||
</ | </lsl> | ||
|helpers= | |helpers= | ||
Tests to see if one string contains a copy of another: | Tests to see if one string contains a copy of another: | ||
| Line 39: | Line 39: | ||
1. Concise & conventional: | 1. Concise & conventional: | ||
< | <lsl> | ||
integer contains(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | integer contains(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | ||
{ | { | ||
return 0 <= llSubStringIndex(haystack, needle); | return 0 <= llSubStringIndex(haystack, needle); | ||
} | } | ||
</ | </lsl> | ||
< | <lsl> | ||
integer startswith(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | integer startswith(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | ||
{ | { | ||
return llGetSubString(haystack, 0, llStringLength(needle) - 1) == needle; | return llGetSubString(haystack, 0, llStringLength(needle) - 1) == needle; | ||
} | } | ||
</ | </lsl> | ||
< | <lsl> | ||
integer endswith(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | integer endswith(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | ||
{ | { | ||
return llGetSubString(haystack, -llStringLength(needle), -1) == needle; | return llGetSubString(haystack, -llStringLength(needle), -1) == needle; | ||
} | } | ||
</ | </lsl> | ||
Note: Some of the snippets above return a result without ever calling llSubStringIndex. | Note: Some of the snippets above return a result without ever calling llSubStringIndex. | ||
| Line 64: | Line 64: | ||
2. Clever & smaller (calculates contains in ~54 bytes rather than ~60): | 2. Clever & smaller (calculates contains in ~54 bytes rather than ~60): | ||
< | <lsl> | ||
integer contains(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | integer contains(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex | ||
{ | { | ||
return ~llSubStringIndex(haystack, needle); | return ~llSubStringIndex(haystack, needle); | ||
} | } | ||
</ | </lsl> | ||
Note: The llSubStringIndex function returns -1 only when not found and the ~ operator returns zero only for -1, so the clever combination ~llSubStringIndex returns zero only for not found, else nonzero for found. | Note: The llSubStringIndex function returns -1 only when not found and the ~ operator returns zero only for -1, so the clever combination ~llSubStringIndex returns zero only for not found, else nonzero for found. | ||
Revision as of 13:54, 30 March 2008
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Summary
Function: integer llSubStringIndex( string source, string pattern );| 0.0 | Forced Delay |
| 10.0 | Energy |
Returns an integer that is the index of pattern in source.
| • string | source | |||
| • string | pattern |
If pattern is not found in source, -1 is returned.
The index of the first character in the string is 0
Caveats
- Performs a literal match (case sensitive).
- Wildcards and RegEx are not supported.
- Attempting to match an empty string ("") will return 0 instead of -1.
Examples
Matching against last names: <lsl> default {
state_entry()
{
llSensorRepeat("", NULL_KEY, AGENT, PI, 96.0, 20);
}
sensor(integer NumDet)
{
integer i;
//Loop through all the sensor data and match against " Linden",
//this causes it to match with any last name of Linden (since there can't be spaces before the firstname)
//Alternatively you could match a firstname with "FirstName "
for(i = 0; i < NumDet; ++i)
if(~llSubStringIndex(llDetectedName(i), " Linden"))
llInstantMessage(llDetectedKey(i), "Hello, I see you!");
}
}
</lsl>Useful Snippets
Tests to see if one string contains a copy of another:
1. Concise & conventional:
<lsl> integer contains(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex {
return 0 <= llSubStringIndex(haystack, needle);
} </lsl>
<lsl> integer startswith(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex { return llGetSubString(haystack, 0, llStringLength(needle) - 1) == needle; } </lsl>
<lsl> integer endswith(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex { return llGetSubString(haystack, -llStringLength(needle), -1) == needle; } </lsl>
Note: Some of the snippets above return a result without ever calling llSubStringIndex.
2. Clever & smaller (calculates contains in ~54 bytes rather than ~60):
<lsl> integer contains(string haystack, string needle) // http://wiki.secondlife.com/wiki/llSubStringIndex {
return ~llSubStringIndex(haystack, needle);
} </lsl>
Note: The llSubStringIndex function returns -1 only when not found and the ~ operator returns zero only for -1, so the clever combination ~llSubStringIndex returns zero only for not found, else nonzero for found.
Note: Smaller was not noticeably faster or slower when our Code Racer and Efficiency Tester harnesses measured the expression { contains("wiki.secondlife.com", "wiki"); }.
See Also
Functions
| • | llListFindList | – | Find a list in another list | |
| • | llGetSubString | – | Copy out part of a string of characters |
Deep Notes
Signature |
|---|
function integer llSubStringIndex( string source, string pattern ); |