A simple converter that converts an extended grammar to a BNF grammar, for the purpose of validating my own grammar in other projects.
Supported constructs: one-or-more +, zero-or-more *, optional ?, literal in non terminal rules as well as group ().
Input format is supposed to be in antlr style grammar, and output format is supposed to be usable in this site.
the display :: Bool -> Grammar -> String function could be triggered to revert the cases of first character in names in order to fully compatible with the
notation used by the grammar analyzer.
The grammar a -> 'foo' b* (c d+ | e 'bar'+) f?. will produce the following rules:
A -> A#1 A#2_st A#3_g A#4_op.
a#1 -> 'foo'.
A#3@1#2_pl1 -> D A#3@1#2_pl2.
A#3@1#2_pl2 -> A#3@1#2_pl1 | .
a#3@2#2 -> 'bar'.
A#3@2#2_pl1 -> A#3@2#2 A#3@2#2_pl2.
A#3@2#2_pl2 -> A#3@2#2_pl1 | .
A#3_g -> C A#3@1#2_pl1 | E A#3@2#2_pl1.
A#2_st -> | B A#2_st.
A#4_op -> | F.
- The output rules are unordered
- Naming of generated rules could be hard to read