Prelude::substr(3) Return a substring.


String substr( String x, Int i, Int len )


x The original string

i The starting index

len The substring length


Starting at character i , return the len characters long substring. Throws an Exception if len is negative, or if i is out-of-bounds. In Kaya 0.2.4 and earlier, an Exception was also thrown if len was zero. The empty string is now returned in this case.

If the starting index is negative, then it will be counted in characters from the end of the string.

 x = "abcdef";
 s = substr(x,0,2); // "ab"
 s = substr(x,4,1); // "e"
 s = substr(x,3,10); // "def" ( len
 s = substr(x,-4,2); // "cd"


Kaya standard library by Edwin Brady, Chris Morris and others ([email protected]). For further information see


The Kaya standard library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (version 2.1 or any later version) as published by the Free Software Foundation.