Oh man. That's subtle. Thanks.
On Oct 1, 2009, at 3:30 PM, Ryan Culpepper <ry...@ccs.neu.edu> wrote:
On Oct 1, 2009, at 4:19 PM, Robby Findler wrote:
What is the difference between generate-temporaries and gensym?
'generate-temporaries' returns identifiers that don't have an
associated '#%top' binding, but 'gensym' returns a symbol, which
gets coerced into an identifier using the lexical context of the
'with-syntax' form, which does have a binding of '#%top' in scope.
Ryan
On Thu, Oct 1, 2009 at 3:11 PM, Sam TH <sa...@ccs.neu.edu> wrote:
On Thu, Oct 1, 2009 at 4:01 PM, Casey Klein
<clkl...@eecs.northwestern.edu> wrote:
Can someone explain why this macro expands without error in a
module
but not in the REPL?
(define-syntax (m stx)
(syntax-case stx ()
[(_ x)
(with-syntax ([(y) (generate-temporaries (syntax (x)))])
(syntax (define (y) y)))]))
(m q)
compile: unbound identifier (and no #%top syntax transformer is
bound) in: q1
This version of the macro works:
(define-syntax (m stx)
(syntax-case stx ()
[(_ x)
(with-syntax ([(y) (list (gensym (syntax-e #'x)))])
(syntax (define (y) y)))]))
--
sam th
sa...@ccs.neu.edu
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