Added unstable/pretty with pretty-format/print, /write, and /display.

collects/unstable/pretty.rkt

@@ -0,0 +1,16 @@
+#lang racket/base
+(require racket/pretty)
+
+(provide pretty-format/write
+         pretty-format/display
+         pretty-format/print)
+
+(define ((pretty-format/pretty f) v [columns (pretty-print-columns)])
+  (parameterize ([current-output-port (open-output-string)]
+                 [pretty-print-columns columns])
+    (f v)
+    (get-output-string (current-output-port))))
+
+(define pretty-format/write (pretty-format/pretty pretty-write))
+(define pretty-format/display (pretty-format/pretty pretty-display))
+(define pretty-format/print (pretty-format/pretty pretty-print))

collects/unstable/scribblings/pretty.scrbl

@@ -0,0 +1,59 @@
+#lang scribble/manual
+@(require scribble/eval "utils.rkt" (for-label racket unstable/pretty))
+
+@title{Pretty-Printing}
+
+@defmodule[unstable/pretty]
+
+This module provides tools for pretty-printing.
+
+@unstable[@author+email["Carl Eastlund" "cce@racket-lang.org"]]
+
+@defproc[(pretty-format/write [x any/c]
+                              [columns
+                               (or/c exact-nonnegative-integer? 'infinity)
+                               (pretty-print-columns)])
+         string?]{
+
+This procedure behaves like @scheme[pretty-format], but it formats values
+consistently with @scheme[write] instead of @scheme[print].
+
+@examples[#:eval (eval/require 'racket/pretty 'unstable/pretty)
+(struct both [a b] #:transparent)
+(pretty-format/write (list (both (list 'a 'b) (list "a" "b"))))
+]
+
+}
+
+@defproc[(pretty-format/display [x any/c]
+                                [columns
+                                 (or/c exact-nonnegative-integer? 'infinity)
+                                 (pretty-print-columns)])
+         string?]{
+
+This procedure behaves like @scheme[pretty-format], but it formats values
+consistently with @scheme[display] instead of @scheme[print].
+
+@examples[#:eval (eval/require 'racket/pretty 'unstable/pretty)
+(struct both [a b] #:transparent)
+(pretty-format/display (list (both (list 'a 'b) (list "a" "b"))))
+]
+
+}
+
+@defproc[(pretty-format/print [x any/c]
+                              [columns
+                               (or/c exact-nonnegative-integer? 'infinity)
+                               (pretty-print-columns)])
+         string?]{
+
+This procedure behaves the same as @scheme[pretty-format], but is named
+more explicitly to describe how it formats values.  It is included for
+symmetry with @scheme[pretty-format/write] and @scheme[pretty-format/display].
+
+@examples[#:eval (eval/require 'racket/pretty 'unstable/pretty)
+(struct both [a b] #:transparent)
+(pretty-format/print (list (both (list 'a 'b) (list "a" "b"))))
+]
+
+}

collects/unstable/scribblings/unstable.scrbl

@@ -79,6 +79,7 @@ Keep documentation and tests up to date.
 @include-section["list.scrbl"]
 @include-section["net.scrbl"]
 @include-section["path.scrbl"]
+@include-section["pretty.scrbl"]
 @include-section["srcloc.scrbl"]
 @include-section["string.scrbl"]
 @include-section["struct.scrbl"]