fix vector-map! to not mutate immutable vectors

pkgs/racket-pkgs/racket-doc/scribblings/reference/vectors.scrbl

@@ -178,19 +178,15 @@ Applies @racket[proc] to the elements of the @racket[vec]s from the
 (vector-map + #(1 2) #(3 4))]
 }
 
-@defproc[(vector-map! [proc procedure?] [vec vector?] ...+) 
+@defproc[(vector-map! [proc procedure?] [vec (and/c vector? (not/c immutable?))] ...+)
          vector?]{
 
-Applies @racket[proc] to the elements of the @racket[vec]s from the
- first elements to the last. The @racket[proc] argument must accept
- the same number of arguments as the number of supplied @racket[vec]s,
- and all @racket[vec]s must have the same number of elements.  The
- each result of @racket[proc] is inserted into the first @racket[vec]
- at the index that the arguments to @racket[proc] was taken from.  The
- result is the first @racket[vec].
+Like @racket[vector-map], but result of @racket[proc] is inserted into
+ the first @racket[vec] at the index that the arguments to
+ @racket[proc] were taken from. The result is the first @racket[vec].
 
 @mz-examples[#:eval vec-eval
-(define v #(1 2 3 4))
+(define v (vector 1 2 3 4))
 (vector-map! add1 v)
 v
 ]}

pkgs/racket-pkgs/racket-test/tests/racket/vector.rktl

@@ -221,6 +221,7 @@
   (let ([vec (vector 1 -2 -3)])
     (test #(1 2 3) vector-map! (lambda (x y) (max x y)) vec #(0 2 3))
     (test #(1 2 3) values vec))
+  (err/rt-test (vector-map! add1 #(1)))
   (err/rt-test (vector-map 1 #()) (check-regs #rx"vector-map" #rx"procedure"))
   (err/rt-test (vector-map (lambda (x) x) 1) (check-regs #rx"vector-map" #rx"vector"))
   (err/rt-test (vector-map (lambda (x) x) #() 1) (check-regs #rx"vector-map" #rx"vector"))

racket/collects/racket/vector.rkt

@@ -55,11 +55,15 @@
 ;; that `v' and all the `vs' have the same length
 ;; and that `f' takes |v + vs| args
 ;; uses name for error reporting
-(define (varargs-check f v vs name)
+(define (varargs-check f v vs name need-mutable?)
   (unless (procedure? f)
     (apply raise-argument-error name "procedure?" 0 f v vs))
-  (unless (vector? v)
-    (apply raise-argument-error name "vector?" 1 f v vs))
+  (unless (and (vector? v)
+               (or (not need-mutable?)
+                   (not (immutable? v))))
+    (apply raise-argument-error name
+           (if need-mutable? "(and/c vector? (not/c immutable?))" "vector?")
+           1 f v vs))
   (let ([len (unsafe-vector-length v)])
     (for ([e (in-list vs)]
           [i (in-naturals 2)])
@@ -86,13 +90,13 @@
     len))
 
 (define (vector-map f v . vs)
-  (let* ([len (varargs-check f v vs 'vector-map)]
+  (let* ([len (varargs-check f v vs 'vector-map #f)]
          [new-v (make-vector len)])
     (vector-map/update f new-v len (cons v vs))
     new-v))
 
 (define (vector-map! f v . vs)
-  (define len (varargs-check f v vs 'vector-map!))
+  (define len (varargs-check f v vs 'vector-map! #t))
   (vector-map/update f v len (cons v vs))
   v)