Add more utility functions

4 files changed, 62 insertions, 16 deletions

diff --git a/configure b/configure
index cd6c3203..35dd4ded 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.63 for OpenAxiom 1.4.0-2010-05-26.
+# Generated by GNU Autoconf 2.63 for OpenAxiom 1.4.0-2010-05-28.
 #
 # Report bugs to <open-axiom-bugs@lists.sf.net>.
 #
@@ -745,8 +745,8 @@ SHELL=${CONFIG_SHELL-/bin/sh}
 # Identity of this package.
 PACKAGE_NAME='OpenAxiom'
 PACKAGE_TARNAME='openaxiom'
-PACKAGE_VERSION='1.4.0-2010-05-26'
-PACKAGE_STRING='OpenAxiom 1.4.0-2010-05-26'
+PACKAGE_VERSION='1.4.0-2010-05-28'
+PACKAGE_STRING='OpenAxiom 1.4.0-2010-05-28'
 PACKAGE_BUGREPORT='open-axiom-bugs@lists.sf.net'
 
 ac_unique_file="src/Makefile.pamphlet"
@@ -1513,7 +1513,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures OpenAxiom 1.4.0-2010-05-26 to adapt to many kinds of systems.
+\`configure' configures OpenAxiom 1.4.0-2010-05-28 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1583,7 +1583,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of OpenAxiom 1.4.0-2010-05-26:";;
+     short | recursive ) echo "Configuration of OpenAxiom 1.4.0-2010-05-28:";;
    esac
   cat <<\_ACEOF
 
@@ -1691,7 +1691,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-OpenAxiom configure 1.4.0-2010-05-26
+OpenAxiom configure 1.4.0-2010-05-28
 generated by GNU Autoconf 2.63
 
 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
@@ -1705,7 +1705,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by OpenAxiom $as_me 1.4.0-2010-05-26, which was
+It was created by OpenAxiom $as_me 1.4.0-2010-05-28, which was
 generated by GNU Autoconf 2.63.  Invocation command line was
 
   $ $0 $@
@@ -21182,7 +21182,7 @@ exec 6>&1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by OpenAxiom $as_me 1.4.0-2010-05-26, which was
+This file was extended by OpenAxiom $as_me 1.4.0-2010-05-28, which was
 generated by GNU Autoconf 2.63.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -21245,7 +21245,7 @@ Report bugs to <bug-autoconf@gnu.org>."
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_version="\\
-OpenAxiom config.status 1.4.0-2010-05-26
+OpenAxiom config.status 1.4.0-2010-05-28
 configured by $0, generated by GNU Autoconf 2.63,
   with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"
 
diff --git a/configure.ac b/configure.ac
index 5f879d6c..29555ad8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,6 @@
 sinclude(config/open-axiom.m4)
 sinclude(config/aclocal.m4)
-AC_INIT([OpenAxiom], [1.4.0-2010-05-26], 
+AC_INIT([OpenAxiom], [1.4.0-2010-05-28], 
         [open-axiom-bugs@lists.sf.net])
 
 AC_CONFIG_AUX_DIR(config)
diff --git a/configure.ac.pamphlet b/configure.ac.pamphlet
index 43c34f12..2f446383 100644
--- a/configure.ac.pamphlet
+++ b/configure.ac.pamphlet
@@ -1210,7 +1210,7 @@ information:
 <<Autoconf init>>=
 sinclude(config/open-axiom.m4)
 sinclude(config/aclocal.m4)
-AC_INIT([OpenAxiom], [1.4.0-2010-05-26], 
+AC_INIT([OpenAxiom], [1.4.0-2010-05-28], 
         [open-axiom-bugs@lists.sf.net])
 
 @
diff --git a/src/interp/g-util.boot b/src/interp/g-util.boot
index 18af0463..7a93d95a 100644
--- a/src/interp/g-util.boot
+++ b/src/interp/g-util.boot
@@ -46,6 +46,51 @@ module g_-util where
   expandToVMForm: %Thing -> %Thing
 
 
+--% VM forms
+
+++ Make the assumption named `prop' for all symbols
+++ on the lis `syms'.
+assumeProperty(syms,prop) ==
+  for s in syms repeat
+    property(s,prop) := true
+
+assumeProperty('(%and %or),'%nary)
+
+++ We are about to construct a middle end expression
+++ with operator `op, and aguments `form'.  Try to
+++ simplify the structure of the expression.
+flattenVMForm(form,op) == main where
+  main() ==
+    atom form => form
+    EQ(form.op,op) => [op,:flatten(form.args,op,nil)]
+    [flattenVMForm(form.op,op),:flattenVMForm(form.args,op)]
+  flatten(forms,op,acc) ==
+    forms = nil => accu
+    x := flattenVMForm(first forms,op)
+    cons? x and EQ(x.op,op) => flatten(rest forms,op,[:accu,:x.args])
+    flatten(rest forms,op,[:accu,x])
+
+++ Build a midde end expression with given operator and arguments.    
+mkVMForm(op,args) ==
+  if op has %nary then
+    args := flattenVMForm(args,op)
+  op = '%or =>
+    args := REMOVE('%false,args)
+    args = nil => '%false
+    args is [arg] => arg
+    [op,:args]
+  op = '%and =>
+    args := REMOVE('%true,args)
+    args = nil => '%true
+    args is [arg] => arg
+    [op,:args]
+  op = '%not =>
+    [arg] := args
+    arg = '%false => '%true
+    arg = '%true => '%false
+    arg is ['%not,arg'] => arg'
+    ['%not,:args]
+
 --%
 --% Opcode expansion to VM codes.
 --%
@@ -568,13 +613,14 @@ getTypeOfSyntax t ==
 bool: %Thing -> %Boolean
 bool x ==
     null null x
- 
+
+++ Return true is the form `x' is a predicate known to always
+++ evaluate to true.
 TruthP x ==
-    --True if x is a predicate that's always true
-  x is nil => nil
-  x=true => true
+  x = nil or x = '%false => false
+  x = true or x = '%true => true
   x is ['QUOTE,:.] => true
-  nil
+  false
 
 --% Record and Union utils.