retoor/wren
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat: add startIndex parameter to string indexOf and update internal find function

Browse Source 
Add a new `indexOf(_,_)` primitive that accepts a start index for searching within strings, and modify the existing `wrenStringFind` function to accept and use a start index parameter. The existing `indexOf(_)` and `contains(_)` methods now pass 0 as the start index to maintain backward compatibility. The Boyer-Moore-Horspool search algorithm is updated to offset comparisons by the start index and return the absolute position in the original string. New test cases verify correct behavior with various start index values including edge cases where the start index exceeds string length.
This commit is contained in:
Bob Nystrom
2016-08-04 04:51:46 +00:00
parent 0e4503726e 0b1a3cc3e5
commit 48b69a7c43
4 changed files with 31 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
test/core/string/index_of.wren
+6
View File
@@ -5,6 +5,12 @@ System.print("abcd".indexOf("abcd")) // expect: 0
System.print("abcd".indexOf("abcde")) // expect: -1
System.print("abab".indexOf("ab")) // expect: 0
System.print("abcd".indexOf("cd", 0)) // expect: 2
System.print("abcd".indexOf("cd", 1)) // expect: 2
System.print("abcd".indexOf("cd", 2)) // expect: 2
System.print("abcd".indexOf("cd", 3)) // expect: -1
System.print("abcd".indexOf("cd", 10)) // expect: -1
// More complex cases.
System.print("abcdefabcdefg".indexOf("defg")) // expect: 9
System.print("abcdabcdabcd".indexOf("dab")) // expect: 3