Re: [Cardinal-dev] Compiler structure / AST format

[Einar Karttunen]

On 24.04 17:39, Phil Tomson wrote:
> That would be good, but see my previous post on Ruth in the archive.  It uses 
> The current Ruby parser (the C/lex/yacc version that comes with the current 
> Ruby) for compatibility with the current version of Ruby.  It seems to me 
> that if we start from scratch (or even if we start with some of the 
> Ruby-in-Ruby parsers already available - like the one in RDoc for example) 
> thta it's going to take quite a lot of our time just to make it compatible 
> with the current incarnation of Ruby.  Ruth, it would seem, would make it 
> easier to chase a moving target.  (that said, though, there are indeed some 
> big advantages to having a Ruby parser written completely in Ruby).
> 

I am currently looking at MetaRuby's RubyScheme which looks promising.

> The intermediate would make it eaiser to 'bolt-on' other VMs or to compile 
> the intermediate to native code (like what is done in .NET and it's clr).
> 

The reason for the immediate is the optimiser pass and the complexity of 
backends.
* backends need to only know about the intermediate code not the AST
* frontends and backends can be switched with no recoding
* some optimisations common to all backends are very unnatural at the AST level

I think that we should try to first have a coherent design and then start coding
so please comment more on the compiler structure && what the intermediate 
language
should be and do we need it at all.

- Einar Karttunen