Lexer and parser generators using CTFE

[Andrei Alexandrescu]

On 2/28/12 11:15 PM, Nick Sabalausky wrote:
> In Goldie, I've taken an inverted approach, which IMHO is easier to use: The
> types are automatically generated from the grammar, not the other way
> around. So applying that approach to the above code, it'd be more like this:
>
> mixin genGrammar!("myGrammar", `
>      Identifier = [a-zA-Z_][a-zA-Z_0-9]*
>      Module = Declaration+
>      Declaration = StructDeclaration
>      StructDeclaration = 'struct' Identifier '{' Declaration* '}'
> `);
>
> Which generates these classes:
>
> Parser!"myGrammar"
> Symbol!("myGrammar.Identifier")
> Symbol!("myGrammar.Module")
> Symbol!("myGrammar.Declaration")
> Symbol!("myGrammar.StructDeclaration")
>
> and/or these:
>
> Parser_myGrammar
> Symbol_myGrammar!"Identifier"
> Symbol_myGrammar!"Module"
> Symbol_myGrammar!"Declaration"
> Symbol_myGrammar!"StructDeclaration"
>
> would could then be aliased by the user however they wanted:
>
> alias Symbol_myGrammar MySym;
>
> And there can still be hooks (delegates, subclassing, whatever) to add
> customized behavior/functionality.

I think this is the right approach.

Andrei