Talk:Recursive descent parser

This page really needs a discussion of the problem of left-recursive grammar rules. Such rules are extremely common, as for example

EXPR = INT | EXPR + EXPR | EXPR * EXPR;

A recursive descent parser, presented with this grammar, will loop forever on a malformed input.

Should probably mention that hand-written recursive descent parsers are usually based on EBNF grammars? These support left-recursion by turning

    A = A b C | C

into

    A = C (b C)*

Paolo Bonzini, 09:34, 8 Mar 2006 (UTC)

Recursive descent parser example

Dominus 04:44, 28 Aug 2003 (UTC)

The code on the page is wrong. Parse_E will parse the string NOTTRUETRUE which is not part of the language.

I don't think it does. Care to demonstrate? -- Jan Hidders 11:22, 28 Aug 2003 (UTC)

maybe the problem is hidden behind the if's, which should be else-if's??

Ah, yes, of course. Hope I fixed that now. -- Jan Hidders 00:51, 4 Nov 2004 (UTC)

Does not look like it accepts this: // ident := number * - number . Symbol symbols[7] = {ident,becomes,number,times,minus,number,period}; Should it?