Re: Elisp lexical-let

[Daniel Kraft <d@domob.eu>]

Ken Raeburn wrote:
> On Jul 22, 2009, at 05:11, Daniel Kraft wrote:
>> It seemed really hard to me to find at least *basic* information about 
>> how the lexbind things works; I did build now an emacs with lexbind 
>> from trunk, but so far as I see this is not meant to implement 
>> "lexical-let" as the cl package does, but rather allows switching all 
>> bindings from dynamic to lexical within one source file.
> 
> Oh... I may have seriously misunderstood; sorry about that.  That's what 
> comes from not having bothered to look. :-)

Ok, I think I'll work on a cl like lexical-let now and see what this 
gives in performance related to dynamic let (and just to get it 
available of course).

The implementation will (for now at least) be as I favour it, that is, 
inner lets revert to dynamic binding (as do inner lambdas for their 
arguments) -- this is more reasonable (I think), has more power (as the 
other way can be achieved by using lexical-let for inner lets when 
preferred, which is also clearer to understand) and should be easier to 
implement (because I don't need to mess around with the compilation of 
let constructs depending on the context).

I'll keep in mind also the lexbind idea of optionally making every 
binding lexical.  Andy, can you give me a hint/example/pointer how 
compiler options work?  This would be exactly the place to provide this, 
I think.  Additionally we could add an option to remove the "variable is 
void" error check for a further performance gain.

Yours,
Daniel

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