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

Better error messages for TR lambda parsing

Browse Source
This commit is contained in:
Asumu Takikawa 2014-02-10 17:32:53 -05:00
parent aef37edae4
commit ad4f6e1ea1
1 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/base-env/prims.rkt
View File

@ -1183,21 +1183,28 @@ This file defines two sorts of primitives. All of them are provided into any mod
#:attr opt-property #:attr opt-property
(list (length (attribute mand)) (length (attribute opt))) (list (length (attribute mand)) (length (attribute opt)))
#:attr erased #:attr erased
(template ((?@ . mand.form) ... (?@ . opt.form) ... . rest.form))))) (template ((?@ . mand.form) ... (?@ . opt.form) ... . rest.form))))
(define-splicing-syntax-class return-ann
#:description "return type annotation"
#:literals (:)
(pattern (~seq : type:expr))
(pattern (~seq) #:attr type #f)))
;; annotation to help tc-expr pick out keyword functions ;; annotation to help tc-expr pick out keyword functions
(define-syntax (-lambda stx) (define-syntax (-lambda stx)
(syntax-parse stx (syntax-parse stx
#:literals (:) #:literals (:)
[(_ formals:lambda-formals (~optional (~seq : return-type:expr)) [(_ formals:lambda-formals return:return-ann
e ... last-e) (~describe "body expression or definition" e) ...
(~describe "body expression" last-e))
;; Annotate the last expression with the return type. Should be correct ;; Annotate the last expression with the return type. Should be correct
;; since if a function returns, it has to do so through the last expression ;; since if a function returns, it has to do so through the last expression
;; even with continuations. ;; even with continuations.
(define/with-syntax last-e* (define/with-syntax last-e*
(if (attribute return-type) (if (attribute return.type)
#`(ann last-e #,(attribute return-type)) #`(ann last-e #,(attribute return.type))
#'last-e)) #'last-e))
(define d (syntax/loc stx (λ formals.erased e ... last-e*))) (define d (syntax/loc stx (λ formals.erased e ... last-e*)))
(if (attribute formals.kw-property) (if (attribute formals.kw-property)