> Avoid using * or + in the right part, as it can cause infinite loops
Why not just disallow this? I understand it would make the grammar more difficult to specify - but I don't see any good reason to keep it.
Why not just disallow this? I understand it would make the grammar more difficult to specify - but I don't see any good reason to keep it.
The rationale was to implement a fun operation called transducer composition. It is possible to do simple operation on strings and compose trre's like filters. But I haven't finished it yet. So again, a fair point.
And then if `-g` were specified, you could use this to create infinite generators, which could be a useful construct in some cases -- like `yes` but more powerful.
EDIT: Another interesting use case, if I am understanding correctly: if this worked, then you could use `:(<regex>)` to have it output an example of a string that matches any given regex. `-g :(<regex>)` produces a generator of every string in the language matched by that regex. `-g :(<regex>) | head -n 100` would give you 100 examples.
You got the idea correctly. E.g. to generate all strings of length 5 over alphabet 10 (and truncate to 10000) you can do:
echo '' | ./trre -am ':[a-c]{5}' | head -n 1000
The docs are fixed now. Thanks for pointing this out.
The infinite generators is something nice to have, I agree. Just didn't wrap my hand around how to do this in 'ergonomically' correct way.