Re: Elisp flet construct

[Daniel Kraft]

Hi Ken,

Ken Raeburn wrote:
> On Jul 21, 2009, at 09:10, Daniel Kraft wrote:
> > Just a little addition to the subject of extensions:  I'd very much 
> > like to add lexical-let and lexical-let* as another set of extensions, 
> > because this gives the possibility to use "fast" lexical variables 
> > without the dynamic-scoping-fluid-pain.
> >
> > Currently, I did implement some control constructs that could be done 
> > as macros still in the compiler directly (like prog1 or dolist) 
> > because there I can make use of lexical helper variables; lexical-let 
> > would allow using this feature directly from elisp (and implementing 
> > these constructs equivalently as macros).
> >
> > So, what do you think about this extension?
>
> Is this modeled on the lexical-let work being done for Emacs (probably 
> to be merged for Emacs 24)?  If so, I wouldn't call it an extension so 
> much as being compatible in advance. :-)  And if not, you should 
> probably take a look at that work and make sure yours is compatible.

hm...  I just found this page which is not decidedly about a planned 
addition to emacs 24, but I think it is quite reasonable that this 
addition will be the extension/feature described here:

http://www.delorie.com/gnu/docs/emacs/cl_21.html

This seems also (as far as I'm no expert on the details) to be just like 
let behaves in Scheme and I plan to implement lexical-let just using 
Guile's real let handling (not the dynamic one based on fluids crafted 
for elisp) -- I hope this is "compatible".

If this is not quite correct, please point me to another source and/or 
let me know the differences between Scheme's let to keep in mind!

Thanks, Daniel

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