In
computer science,
pattern matching is the act of checking a given
sequence of tokens for the presence of the constituents of some
pattern. In contrast to
pattern recognition, the match usually has to be exact. The patterns generally have the form of either
sequences or
tree structures. Uses of pattern matching include outputting the locations (if any) of a pattern within a token sequence, to output some component of the matched pattern, and to substitute the matching pattern with some other token sequence (i.e.,
search and replace).