On Wed, Sep 08, 2004 at 09:56:12AM -0700, Larry Wall wrote: > On Wed, Sep 08, 2004 at 07:33:45AM -0600, Patrick R. Michaud wrote: > : We're in the beginning stages of building a basic perl 6 grammar engine > : (i.e., probably without p6 closures) that compiles to parrot and handles > : basic optimizations. > > I wonder whether, in the absence of closures, we'll have to have some > similar way to embed syntax-tree building code (PIR?) as actions in > the grammar.
We may indeed need this. I think the easiest way would be to build some sort of "special-purpose" assertions or rules that fire off some PIR code. Or, perhaps we can just find a way to do a funky sort of replacement whereby p6 source code gets replaced by its equivalent PIR code as soon as the compiler think it has a rule matched. Naaah, scratch that. > Perhaps most of the grammar can rely on the built-up > tree of $0 nodes, but we'll at least have to have an escape down into > the operator precedence parser. [...] But I'm just a little > scared that operator precedence will be one of those optimizations > that's always the project after this one... [...] No, I'm expecting that we'll go ahead and build something to deal with operator precedence early on, at least for bootstrapping purposes. This is part of the reason why I was eager to see the precedence tables get nailed down a bit more. Pm
