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Re: [Chicken-users] stressing the new hygienic macros
From: |
Michele Simionato |
Subject: |
Re: [Chicken-users] stressing the new hygienic macros |
Date: |
Wed, 29 Apr 2009 08:30:49 +0200 |
On Tue, Apr 28, 2009 at 7:08 PM, Alex Shinn <address@hidden> wrote:
> Michele Simionato <address@hidden> writes:
> Chicken 4 extends define-syntax with the er-macro-transformer spec,
> (and with raw lambdas which mean the same thing), but these
> are hard-coded.
>
> Al* Petrofsky specifically argued that this be allowed, as
> well as
>
> (let-syntax ((foo some-other-macro))
> ...)
>
> and implemented it in his alexpander. It's a necessary
> feature for the user to provide his/her own syntax
> transformers defined in terms of existing transformers
> (e.g. super-syntax-rules with extended pattern matching).
>
> The other syntactic-closures and riaxpander macros systems
> in Chicken 3 also support it, as do MIT Scheme, Ikarus and
> Chibi-Scheme. PLT doesn't.
PLT does, I have tested it in R6RS mode; it requires some incantation
with metalevels though.
Anyway, this is bad news for me. It means that if I want to define
my own syntax transformers I have to implement them from
scratch from low level macros :-(
My final purpose would be to port my sweet-macros
system to Chicken; see episode #9 of my
Adventures: http://www.artima.com/weblogs/viewpost.jsp?thread=251474