fsa4streams 0.2

An implementation of Finite State Automata for event streams

This is a library for running Finite State Automata (FSA) on bound and unbound streams of event.

It supports

• non-determininistic FSA’s,

• noise-tolerant FSA’s (i.e. ignoring some or all non-relevant events),

• overlapping matched,

• extensible matching functions for transitions.

TODO: proper documentation

It should describe:

• how to use the library, through tutorials

  • demonstrating in particular the various ways to build noise-tolerant FSA’s (silent transitions, default transitions, global and state max_noise),

  • explaining the notion of token,

  • explaining the role of finish(), and why a token on a final state may not immediately return a match;

• the structure of tokens (as returned by feed() and feed_all();

• the format of the JSON files used to store FSA structures,

  • may be also the format of the JSON files used to save tokens;

• how to write additional matcher functions,

  • and how they may be used to extend the expressiveness of FSA beyond regular grammars;

• some of the design choices of the library,

  • especially why an empty sequence is never a match, even if the ‘start’ state is marked as terminal.

Ideas for future extensions

• export to dot (for graphical presentation)

• toolkit for handling FSA’s - optimizing - merging

• more built-in matchers? - prefix - more flexible regexp (i.e. not enforcing ^ and $)

• converter of regexp to automata