[R6RS] syntax-case semantics
William D Clinger
will at ccs.neu.edu
Sat Mar 18 19:15:21 EST 2006
> I might buy the "hygiene issue" or whatever you want to call
> it if I had ever run into it or seen anyone else run into it,
> but I haven't. So I prefer the traditional semantics.
I have run into the problem, so I prefer SRFI 72's semantics.
I also prefer SRFI 72's less opaque definition of a syntax object,
because it is less mysterious and because it allows the authors
of procedural macros to reuse more of Scheme's standard library
without having to mess with syntax-object->datum or syntax->list.
I also like SRFI 72's description of its semantics in terms of
a reflective tower.
I don't see much problem with the hash-table implementation of
source locations, because it should be easy to modify the macro
expander to record that information within fully macro-expanded
code in an implementation's preferred way, discarding the hash
table afterwards. There is no need for weak pointers.
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