Basic format checking takes 20 (of 75) seconds in strc for libdryad. The performance of format checking must be improved, either by optimizing the current implementation (improved use of dynamic rules) or implementing a format checker compiler (as opposed to the current interpreter).

Submitted on 9 August 2005 at 22:05

STR-398, visser:
this is a (performance) bug; annoying, but not critical at this stage

STR-398, martin:
A small benchmark: libstratego-lib takes 42.6 seconds with format-checking, 18.2 without. Obviously, this is horrible. Working on a better algorithm.

STR-398, martin:
The DFTA-based format checker has now been introduced in the library, side-by-side with old format-checker.

For some grammars, there is an explosion problem with DFTA’s (e.g. Java has more than 300.000 states, which introduces some I/O problems: the .dfta is 24MB). For now, I will keep the old format-checker in the codebase and make the use of DFTA’s optional (since it is already most useful for the Stratego syntax).

We need to investigate if minimization of the DFTA solves the explosion problem. If so, then we can dump the old format checker once rtg-minimize has been implemented.