Fast non-overlapping Knuth-Morris-Pratt search of both strict and lazy ByteString values.

A description of the algorithm can be found at http://en.wikipedia.org/wiki/Knuth-Morris-Pratt_algorithm.

This module exports 4 search functions: matchLL, matchLS, matchSL, and matchSS.

If given an empty pattern, a search will always return an empty list.

The first parameter is always the pattern string. The second parameter is always the target string to be searched. The returned list contains the offsets of all non-overlapping patterns.

A returned Int or Int64 is an index into the target string which is aligned to the head of the pattern string. Strict targets return Int indices and lazy targets return Int64 indices. All returned lists are computed and returned in a lazy fashion.

matchLL and matchLS take lazy bytestrings as patterns. For performance, if the pattern is not a single strict chunk then all the the pattern chunks will copied into a concatenated strict bytestring. This limits the patterns to a length of (maxBound :: Int).

matchLL and matchSL take lazy bytestrings as targets. These are written so that while they work they will not retain a reference to all the earlier parts of the the lazy bytestring. This means the garbage collector would be able to keep only a small amount of the target string and free the rest.