guile.m4

[Aaron VanDevender]

Here is a slightly improved version of my guile.m4 patch. It has some
more explicit comments and uses the guile executable set by GUILE_PROGS

Index: guile.m4
===================================================================
RCS file: /sources/guile/guile/guile-core/guile-config/guile.m4,v
retrieving revision 1.8
diff -u -r1.8 guile.m4
--- guile.m4    16 Apr 2006 23:36:35 -0000      1.8
+++ guile.m4    13 Jun 2006 14:35:50 -0000
@@ -23,6 +23,7 @@
 ## GUILE_FLAGS -- set flags for compiling and linking with Guile
 ## GUILE_SITE_DIR -- find path to Guile "site" directory
 ## GUILE_CHECK -- evaluate Guile Scheme code and capture the return value
+## GUILE_CHECK_VERSION -- checks for a version of the guile interpreter
 ## GUILE_MODULE_CHECK -- check feature of a Guile Scheme module
 ## GUILE_MODULE_AVAILABLE -- check availability of a Guile Scheme module
 ## GUILE_MODULE_REQUIRED -- fail if a Guile Scheme module is unavailable
@@ -112,7 +113,7 @@
 
 # GUILE_CHECK -- evaluate Guile Scheme code and capture the return value
 #
-# Usage: GUILE_CHECK_RETVAL(var,check)
+# Usage: GUILE_CHECK(var,check)
 #
 # @var{var} is a shell variable name to be set to the return value.
 # @var{check} is a Guile Scheme expression, evaluated with "$GUILE -c", and
@@ -126,6 +127,36 @@
   $1=$?
  ])
 
+# GUILE_CHECK_VERSION -- check for a particular Guile version
+#
+# Usage: GUILE_CHECK_VERSION(MIN-VERSION, [ACTION-IF-FOUND], 
[ACTION-IF-NOTFOUND])
+#
+# @var{MIN-VERSION} is the minimum guile version to check for.
+# @var{ACTION-IF-FOUND} is an action to perform if guile version MIN-VERSION or
+#    or greater is found. Defaults to do nothing.
+# @var{ACTION-IF-NOT-FOUND} is an action to perform if no guile version 
MIN-VERSION
+#    or greater is found. Defaults to throwing a configure error.
+AC_DEFUN([GUILE_CHECK_VERSION],
+[AC_REQUIRE([GUILE_PROGS])dnl
+AC_MSG_CHECKING([for guile version >= $1])
+GUILE_CHECK([GUILE_CORRECT_VERSION_P],
+    [(exit (let loop ((v1 (map string->number (string-split (version) 
(string-ref \".\" 0))))
+             (v2 (map string->number (string-split \"$1\" (string-ref \".\" 
0)))))
+             (cond ((and (null? v1) (null? v2)) 0)
+                   ((null? v1) 0)
+                   ((null? v2) 1)
+                   ((> (car v1) (car v2)) 0)
+                   ((< (car v1) (car v2)) 1)
+                   (else (loop (cdr v1) (cdr v2))))))])
+AC_SUBST(GUILE_VERSION,[`$GUILE -c "(display (version))"`])
+if test 0 -eq "$GUILE_CORRECT_VERSION_P" ; then
+   AC_MSG_RESULT([yes ($GUILE_VERSION)])
+m4_ifval([$2], [   $2])dnl
+   else
+   AC_MSG_RESULT([no ($GUILE_VERSION)])
+m4_ifvaln([$3], [   $3], [   AC_MSG_ERROR([requires guile >= $1])])dnl
+fi])
+
 # GUILE_MODULE_CHECK -- check feature of a Guile Scheme module
 #
 # Usage: GUILE_MODULE_CHECK(var,module,featuretest,description)