Thanks Lukas, and agree generating strings considering lookahead and ! should be very hard! I dont know how one could generate valid string according to NOT and Lookaheads. cheers.
On Fri, Sep 5, 2014 at 7:23 AM, Lukas Renggli <reng...@gmail.com> wrote: > The PetitParser UI [1] has the capability to display random examples of a > selected production. Unfortunately the UI (and the example generating code) > is only available in Smalltalk and hasn't been ported to other host > languages. However, you can look at the code here [2] and play with the > tool by downloading the one-click distribution [3]. > > The example generating code is really short and simple (less than 30 > lines, the rest is markup from the export). There are a few (hardcoded) > heuristics to make it produce a short and readable example. > > Note that the code ignores logical predicates (! and & expressions). I am > not sure, if it is even possible to make them work in a generic case? > Either way, I found that ignoring the predicates isn't as bad as it sounds. > Predicates are rarely used in practice and do have a big effect on the > resulting output (as long as you are aware of it). > > To summarise, I find the examples quite useful while developing new > grammars. It allows one to quickly spot errors or edge-cases that might get > missed otherwise. > > Cheers, > Lukas > > [1] http://scg.unibe.ch/archive/papers/Reng10cDynamicGrammars.pdf (Section > 3.5) > [2] > http://www.lukas-renggli.ch/dropbox/petitparser/libraries/PetitParser-Example.st > [3] http://source.lukas-renggli.ch/built/oneclick/PetitParser-OneClick.zip > > > On 4 September 2014 19:54, mathew palsberg <matpalsb...@gmail.com> wrote: > >> Hello, >> I recently built a small language with PEG. I now want to test my >> language with random generated(not necessarily meaningful) programs. Does >> anybody know a tool that given a PEG grammar, it generates random sequences >> that satisfy the given grammar? >> >> Thanks; >> >> >> _______________________________________________ >> PEG mailing list >> PEG@lists.csail.mit.edu >> https://lists.csail.mit.edu/mailman/listinfo/peg >> >> > > > -- > Lukas Renggli > www.lukas-renggli.ch >
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