The pattern matcher in `syntax-case` is less powerful than the one in
`syntax-parse`. The pattern
(_ trash-left ... save-the-world . trash-right)
can match `save-the-world` only against the last item in a list --- or
against the first of the last pair for a non-list.
With `syntax-parse`, as
Thanks for the explanation! Does this mean that syntax-case simply doesn't have
a way to write a pattern that matches save-the-world anywhere in the list? I'm
also curious why these two constructs have such different pattern matchers. Is
it just that syntax-parse is newer and will one day
That's right: `syntax-case` doesn't have a way to write that as a
pattern.
And yes: `syntax-parse` is newer and will one day supplant `syntax-case`
(more completely than it has already).
At Thu, 28 Jan 2016 06:03:46 -0800 (PST), reilithion wrote:
> Thanks for the explanation! Does this mean that
I was trying to write a macro today (I'm not too good at writing macros yet)
and I ran up against a wall when I realized that syntax-case wasn't behaving
the way I expected. I boiled down the behavior to the following test case:
#lang racket/base
(require (for-syntax racket/base))
;; Intended
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