Multiple definition for Rule/Class error not consistent

[alberth]

• parglare version: bc33add (Jan 27, 2018)
• Python version: 3.5.2
• Operating System: linux, ubuntu

Description

parglare sometimes accepts multiple definitions of the same non-terminal, and sometimes it doesn't.
Example case:

from parglare import Grammar
from parglare import Parser

text = "a"

gram1 = """\
A : "a" ;
A : "b" ;
"""

grammar = Grammar.from_string(gram1) # line 11
parser = Parser(grammar)
result = parser.parse(text)
print(result)

gram2 = """\
A : t="a" ;
A : t="b" ;
"""

grammar = Grammar.from_string(gram2) # line 21
parser = Parser(grammar)
result = parser.parse(text)
print(result)

Produces

a
Traceback (most recent call last):
  File "m.py", line 21, in <module>
    grammar = Grammar.from_string(gram2)
  File "~/compiler3/parglare/grammar.py", line 615, in from_string
    .parse(grammar_str, context=context),
  File "~/compiler3/parglare/parser.py", line 381, in parse
    context)
  File "~/compiler3/parglare/parser.py", line 619, in _call_reduce_action
    result = sem_action(context, subresults)
  File "~/compiler3/parglare/grammar.py", line 961, in act_production_rule
    .format(name))
parglare.exceptions.GrammarError: Multiple definition for Rule/Class "A"

Note that it crashes at line 21, but not line 11.

EDIT:

The only difference between both grammars are the t= additions in grammar2.

Merging both alternatives with a | avoids the crash.

[igordejanovic]

Thanks for detailed report and test case. Looks like a bug. Will investigate.

[igordejanovic]

@alberth Fixed on master.