Statically typed BNF with semantic actions in python

Typed BNF

Given a grammar:

shape token {
    lexeme : str
}
polyrule  : <a> <b>  { fn (a) -> ($1.lexeme, $2, a) }
polyrule2 : <a> polyrule { fn (a) -> $2(a) }

We type inference it:

polyrule : forall 'a. ('a) -> (str, token, 'a)
polyrule2 : forall 'a. ('a) -> (str, token, 'a)

Then we can lower it to a BNF grammar used by other parser framework, no matter which programming language is the target.

Lark Backend

python -m tbnf GRAMMAR.tbnf lark [--outdir OUTDIR=.] [--mod MODULENAME=mylang]  

Antlr Backend

python -m tbnf GRAMMAR.tbnf antlr [--outdir OUTDIR=.] [--mod MODULENAME=mylang]  

GitHub - thautwarm/typed-bnf: Statically typed BNF with semantic actions; A frontend of frontend frameworks; Use your grammar everywhere.

Statically typed BNF with semantic actions; A frontend of frontend frameworks; Use your grammar everywhere. - GitHub - thautwarm/typed-bnf: Statically typed BNF with semantic actions; A frontend o...

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