piantado / lotlib3 Goto Github PK

Awesome library, thank you!

I have a minor design suggestion that I think would make the library a bit more intuitive and easy to use. At the moment, primitive functions are registered by assigning them to builtins.__dict__. This makes it difficult to benchmark different grammars with different versions of the same primitive functions, especially when those functions are given the same name. Basically you can only use one grammar version per interpreter session.

One alternative would be to have register_primitive assign the primitive function to a specific grammar instance. You'd have to modify LOTHypothesis.compile_function() to somehow factor in self.grammar when evaluating the expression string.

Just a thought - perhaps this change is a little more nuanced than I imagine.

hi, great library. asking a question here in case it is useful to someone later. I'm not entirely clear on the advantages of using a string versus a LOTLib-provided primitive. For instance, both of these should work the same from the user/modeler perspective:

grammar.add_rule('EXPR', '(%s + %s)', ['EXPR', 'EXPR'], 1.0)

and

grammar.add_rule('EXPR', 'plus_', ['EXPR', 'EXPR'], 1.0)

with the later using the built-in 'plus_' primitive. I understand the registering new primitives is critical for adding custom functionality but unclear why LOTlib3 goes so far as to provide primitive things like addition if they would be interpreted correctly by the python interpreter just as a string.

thanks!

I tried this: a simple right branching grammar for binary sequences

grammar = Grammar(start='S')

# basic symbols
grammar.add_rule('S', '"0"', None, 0.5)
grammar.add_rule('S', '"1"', None, 0.5)

# concatenation
grammar.add_rule('S', 'concat_', ['"0"', 'S'], 1)
grammar.add_rule('S', 'concat_', ['"1"', 'S'], 1)
grammar.add_rule('S', 'concat_', ['"101"', 'S'], 1)

trees = grammar.enumerate_at_depth(1)

for t in trees:
    print(t)

get error

`RuntimeError Traceback (most recent call last)
/Users/hh7792/Desktop/Knitting/Knitting.ipynb Cell 6 line 1
16 trees = grammar.enumerate_at_depth(1)
18 # t = eval(str(formula))
---> 19 for t in trees:
20 print(t)

File ~/Desktop/Knitting/LOTlib3/Grammar.py:297, in Grammar.enumerate_at_depth(self, d, nt, leaves)
294 # BVRuleContextManager here makes us remove the rule BEFORE yielding,
295 # or else this will be incorrect. Wasteful but necessary.
296 with BVRuleContextManager(self, fn, recurse_up=False):
--> 297 yieldfn.args = next(myiter)
298 for a in yieldfn.argFunctionNodes():
299 # Update parents
...
--> 316 state[idx] = next(iterators[idx])
317 break # break the idx loop (which would process "carries")
318 except StopIteration:

RuntimeError: generator raised StopIteration`