| Copyright | Justin Bailey Chris Kuklewicz Daniel Fischer |
|---|---|
| License | BSD3 |
| Maintainer | Daniel Fischer <daniel.is.fischer@googlemail.com> |
| Stability | Provisional |
| Portability | non-portable (BangPatterns) |
| Safe Haskell | None |
| Language | Haskell98 |
Data.ByteString.Search.KMP
Description
Fast search of strict ByteString values using the
Knuth-Morris-Pratt algorithm.
A description of the algorithm can be found at http://en.wikipedia.org/wiki/Knuth-Morris-Pratt_algorithm.
Original authors: Justin Bailey (jgbailey at gmail.com) and Chris Kuklewicz (haskell at list.mightyreason.com).
- indices :: ByteString -> ByteString -> [Int]
- nonOverlappingIndices :: ByteString -> ByteString -> [Int]
Overview
This module provides two functions for finding the occurrences of a pattern in a target string using the Knuth-Morris-Pratt algorithm. It exists only for systematic reasons, the functions from Data.ByteString.Search are much faster, except for very short patterns, in which case Data.ByteString.Search.DFA provides better functions.
Complexity and Performance
The preprocessing of the pattern is O(patternLength) in time and space.
The time complexity of the searching phase is O(targetLength) for both
functions.
In most cases, these functions are considerably slower than the Boyer-Moore variants, performance is close to that of those from Data.ByteString.Search.DFA.
Partial application
Both functions can be usefully partially applied. Given only a pattern, the auxiliary data will be computed only once, allowing for efficient re-use.
Functions
Arguments
| :: ByteString | Pattern to find |
| -> ByteString | String to search |
| -> [Int] | Offsets of matches |
Arguments
| :: ByteString | Pattern to find |
| -> ByteString | String to search |
| -> [Int] | Offsets of matches |
nonOverlappingIndicesindices.