[R6RS] syntax-case semantics
mflatt at cs.utah.edu
Fri Mar 17 11:43:16 EST 2006
At Fri, 17 Mar 2006 05:49:19 -0500, Anton van Straaten wrote:
> Might it make sense to add to traditional syntax-case something like a
> FRESH-SYNTAX form, which uses the SRFI 72 semantics? That would allow
> the sorts of problem examples given in the SRFI to be written safely and
A data point, for what it's worth:
MzScheme has this, in the form of `make-syntax-introducer'.
It has been especially useful once, in a case where a set of macros
effectively re-implement a local macro expander; this expander works
with a set of transformers that shouldn't be confused with normal macro
transformers, thought they act essentially the same. (This sub-language
of expanders is for expanding lexer abbreviations in our parser tools.)
In one other place, `make-syntax-introducer' is used to generate a
temporary name that prints the same as some other name.
Many other attempts to use `make-syntax-introducer' have turned out to
be bad ideas.
I don't think I've ever tried to use it to solve a meta-hygiene
problem, but maybe only because the problem hasn't shown up.
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