* New scheme/function module (added by mistake on the previous commit)

* Added it to scheme/main
* Documented it

svn: r9018

collects/scheme/function.ss

@@ -1,6 +1,6 @@
 #lang scheme/base
 
-(provide negate curry)
+(provide negate curry curryr)
 
 (define (negate f)
   (unless (procedure? f) (raise-type-error 'negate "procedure" f))
@@ -21,7 +21,7 @@
 (define (curry f . args)
   (unless (procedure? f) (raise-type-error 'curry "procedure" f))
   (let loop ([args args])
-    (define curry
+    (define curried
       (if (null? args) ; always at least one step
         (lambda more (loop more))
         (lambda more
@@ -29,4 +29,17 @@
             (if (procedure-arity-includes? f (length args))
               (apply f args)
               (loop args))))))
-    curry))
+    curried))
+
+(define (curryr f . args)
+  (unless (procedure? f) (raise-type-error 'curry "procedure" f))
+  (let loop ([args args])
+    (define curried-right
+      (if (null? args) ; always at least one step
+        (lambda more (loop more))
+        (lambda more
+          (let ([args (append more args)])
+            (if (procedure-arity-includes? f (length args))
+              (apply f args)
+              (loop args))))))
+    curried-right))

collects/scheme/main.ss

@@ -10,6 +10,7 @@
            scheme/tcp
            scheme/udp
            scheme/list
+           scheme/function
            scheme/path
            scheme/file
            scheme/cmdline
@@ -30,6 +31,7 @@
                          scheme/tcp
                          scheme/udp
                          scheme/list
+                         scheme/function
                          scheme/path
                          scheme/file
                          scheme/cmdline

collects/scribblings/reference/pairs.scrbl

@@ -42,8 +42,8 @@
                 "Returns " (to-element 'equiv)))))]))
 
 
-@(define list-eval (make-base-eval))
-@interaction-eval[#:eval list-eval (require scheme/list)]
+@(begin (define list-eval (make-base-eval))
+        (interaction-eval #:eval list-eval (require scheme/list)))
 
 
 @title[#:tag "pairs"]{Pairs and Lists}

collects/scribblings/reference/procedures.scrbl

@@ -346,3 +346,56 @@ by @scheme[arity]). For most primitives, this procedure returns
 @scheme[1], since most primitives return a single value when
 applied.}
 
+@; ----------------------------------------
+@section{Additional Procedure Functions}
+
+@note-lib[scheme/function]
+@(begin (define fun-eval (make-base-eval))
+        (fun-eval '(require scheme/function))
+        (define-syntax fun-examples
+          (syntax-rules ()
+            [(_ e ...) (examples #:eval fun-eval e ...)])))
+
+@defproc[(negate [proc procedure?]) procedure?]{
+
+Returns a procedure that is just like @scheme[proc], except that it
+returns the negation of the result.  The resulting procedure has the
+same arity as @scheme[proc].
+
+@fun-examples[
+(filter (negate symbol?) '(1 a 2 b 3 c))
+]}
+
+@defproc*[([(curry [proc procedure?]) procedure?]
+           [(curry [proc procedure?] [v any/c] ...+) procedure?])]{
+
+@scheme[(curry proc)] returns a procedure that is a curried version of
+@scheme[proc].  When the resulting procedure is applied on an
+insufficient number of arguments, it returns a procedure that expects
+additional arguments.  However, at least one such application step is
+required in any case, even if the @scheme[proc] consumes any number of
+arguments.
+
+If additional values are provided to @scheme[curry], they are used as
+the first step.  (This means that @scheme[curry] itself is curried.)
+
+@fun-examples[
+(map ((curry +) 10) '(1 2 3))
+(map (curry + 10) '(1 2 3))
+(map (compose (curry * 2) (curry + 10)) '(1 2 3))
+]
+
+}
+
+@defproc*[([(curryr [proc procedure?]) procedure?]
+           [(curryr [proc procedure?] [v any/c] ...+) procedure?])]{
+
+Like @scheme[curry], except that the arguments are collected in the
+opposite direction: the first step collects the rightmost group of
+arguments, and following steps add arguments to the left of these.
+
+@fun-examples[
+(map (curryr list 'foo) '(1 2 3))
+]
+
+}