Add function parsing to simple pyparsing arithmetics grammar

Question

I have this code:

    import pyparsing as pp

    point = pp.Literal(\".\")

    number = pp.Combine(pp.Word(pp.nums) + pp.Optional(point + pp.Word(pp.nums)))

          


        

Answer 1

In this grammar, a function call is at the same level as a variable reference or numeric literal, so I would add it as part of the definition of atom:

function_call = Group(ident + lpar + Group(Optional(delimitedList(expr))) + rpar)

atom = number | function_call | ident | pp.Group(lpar + expr + rpar)

Also note the use of delimitedList in place of expr + ZeroOrMore(comma + expr).