Sequitur is a linear-time algorithm identifying hierarchical structure in sequences, for example:

Sequence:

abcabdabcabd\n

Grammar:

Rule                 Expansion
----------------     ---------
S -> 0 -> 1 1 \n                                       
1 -> 2 c 2 d         abcabd
2 -> a b             ab

Sequitur is implemented in Java, C++.

This module is to implement Sequitur in Perl.