Factorize and optimize `write' for strings and characters.

According to `write.bm', this makes `write' 2.6 times faster for strings.

* libguile/print.c (iprin1): Use `write_character' when
  `SCM_WRITINGP (pstate)' and `SCM_CHARP (exp)' or `scm_is_string (exp)'.
  (scm_i_charprint): Remove.
  (display_character, write_character): New functions.
  (scm_write_char): Use `display_character' instead of
  `scm_i_charprint'.

* libguile/print.h (scm_i_charprint): Remove declaration.

* benchmark-suite/benchmarks/write.bm: New file.

* benchmark-suite/Makefile.am (SCM_BENCHMARKS): Add
  `benchmarks/write.bm'.

2 files changed, 54 insertions, 1 deletions

diff --git a/benchmark-suite/Makefile.am b/benchmark-suite/Makefile.am
index b58219a24..9f49f2aad 100644
--- a/benchmark-suite/Makefile.am
+++ b/benchmark-suite/Makefile.am
@@ -11,7 +11,8 @@ SCM_BENCHMARKS = benchmarks/0-reference.bm		\
 		 benchmarks/subr.bm			\
 		 benchmarks/uniform-vector-read.bm	\
 		 benchmarks/vectors.bm			\
-		 benchmarks/vlists.bm
+		 benchmarks/vlists.bm			\
+		 benchmarks/write.bm
 
 EXTRA_DIST = guile-benchmark lib.scm $(SCM_BENCHMARKS)	\
 	     ChangeLog-2008
diff --git a/benchmark-suite/benchmarks/write.bm b/benchmark-suite/benchmarks/write.bm
new file mode 100644
index 000000000..e96f2efeb
--- /dev/null
+++ b/benchmark-suite/benchmarks/write.bm
@@ -0,0 +1,52 @@
+;;; write.bm --- Exercise the printer.               -*- Scheme -*-
+;;;
+;;; Copyright (C) 2008, 2010 Free Software Foundation, Inc.
+;;;
+;;; This program is free software; you can redistribute it and/or
+;;; modify it under the terms of the GNU Lesser General Public License
+;;; as published by the Free Software Foundation; either version 3, or
+;;; (at your option) any later version.
+;;;
+;;; This program is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU Lesser General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with this software; see the file COPYING.LESSER.  If
+;;; not, write to the Free Software Foundation, Inc., 51 Franklin
+;;; Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+(define-module (benchmarks read)
+  #:use-module (benchmark-suite lib))
+
+(define %len 50000)
+
+(define %string-with-escapes
+  (list->string (map integer->char (iota %len))))
+
+(define %string-without-escapes
+  (make-string %len #\a))
+
+;; Use Unicode-capable ports.
+(fluid-set! %default-port-encoding "UTF-8")
+
+(define %null
+  (%make-void-port OPEN_WRITE))
+
+
+(with-benchmark-prefix "write"
+
+  (benchmark "string with escapes" 50
+    (write %string-with-escapes %null))
+
+  (benchmark "string without escapes" 50
+    (write %string-without-escapes %null)))
+
+(with-benchmark-prefix "display"
+
+  (benchmark "string with escapes" 1000
+    (display %string-with-escapes %null))
+
+  (benchmark "string without escapes" 1000
+    (display %string-without-escapes %null)))