suzanne.soy/beautiful-racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix br:define

Browse Source
This commit is contained in:
Matthew Butterick 2016-04-08 10:47:16 -07:00
parent f6a680950c
commit 43d8464743
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
br/define.rkt
View File

@ -33,6 +33,11 @@
#:literals (syntax)
#:description "id in syntaxed form"
(pattern (syntax name:id)))
(define-syntax-class syntaxed-thing
#:literals (syntax)
#:description "some datum in syntaxed form"
(pattern (syntax thing:expr)))
(syntax-parse stx
#:literals (syntax)
@ -47,6 +52,9 @@
[(_ sid:syntaxed-id sid2:syntaxed-id) ; (define #'f1 #'f2)
#'(define-syntax sid.name (make-rename-transformer sid2))]
[(_ sid:syntaxed-id sid2:syntaxed-thing) ; (define #'f1 #'42)
#'(define-syntax sid.name (λ (stx) sid2))]
[(_ (sid:syntaxed-id stx-arg ...) expr ...) ; (define (#'f1 stx) expr ...)
(raise-syntax-error 'define "definition of a syntax transformer must use lambda notation, because otherwise it's too easy to confuse the compile-time shape and the run-time shape" (syntax->datum #'sid.name))]