Add "annotations" procedure

2021-05-25 11:02:36 +02:00 · 2021-05-25 11:02:36 +02:00 · 4ed8fd2c92
parent 669d1b480d
commit 4ed8fd2c92
1 changed files with 6 additions and 0 deletions
--- a/implementations/racket/preserves/preserves/annotation.rkt
+++ b/implementations/racket/preserves/preserves/annotation.rkt
@ -2,6 +2,7 @@

 (provide (struct-out annotated)
         annotate
+         annotations
         strip-annotations
         strip-annotations-proc
         peel-annotations
@ -37,6 +38,11 @@
    [item
     (annotated as #f item)]))

+(define (annotations v)
+  (match v
+    [(annotated annotations _ _) annotations]
+    [_ '()]))
+
 (define (strip-annotations-proc v #:depth [depth +inf.0])
  (let walk* ((v v) (depth depth))
    (define next-depth (- depth 1))