* syntax.spad (nil?$Syntax): New predicate.

5 files changed, 21 insertions, 11 deletions

diff --git a/configure b/configure
index 4f758971..1778860f 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.60 for OpenAxiom 1.1.0-2007-12-09.
+# Generated by GNU Autoconf 2.60 for OpenAxiom 1.1.0-2007-12-11.
 #
 # Report bugs to <open-axiom-bugs@lists.sf.net>.
 #
@@ -713,8 +713,8 @@ SHELL=${CONFIG_SHELL-/bin/sh}
 # Identity of this package.
 PACKAGE_NAME='OpenAxiom'
 PACKAGE_TARNAME='openaxiom'
-PACKAGE_VERSION='1.1.0-2007-12-09'
-PACKAGE_STRING='OpenAxiom 1.1.0-2007-12-09'
+PACKAGE_VERSION='1.1.0-2007-12-11'
+PACKAGE_STRING='OpenAxiom 1.1.0-2007-12-11'
 PACKAGE_BUGREPORT='open-axiom-bugs@lists.sf.net'
 
 ac_unique_file="src/Makefile.pamphlet"
@@ -1388,7 +1388,7 @@ 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 1.1.0-2007-12-09 to adapt to many kinds of systems.
+\`configure' configures OpenAxiom 1.1.0-2007-12-11 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1458,7 +1458,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of OpenAxiom 1.1.0-2007-12-09:";;
+     short | recursive ) echo "Configuration of OpenAxiom 1.1.0-2007-12-11:";;
    esac
   cat <<\_ACEOF
 
@@ -1562,7 +1562,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-OpenAxiom configure 1.1.0-2007-12-09
+OpenAxiom configure 1.1.0-2007-12-11
 generated by GNU Autoconf 2.60
 
 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
@@ -1576,7 +1576,7 @@ 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 1.1.0-2007-12-09, which was
+It was created by OpenAxiom $as_me 1.1.0-2007-12-11, which was
 generated by GNU Autoconf 2.60.  Invocation command line was
 
   $ $0 $@
@@ -25203,7 +25203,7 @@ 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 1.1.0-2007-12-09, which was
+This file was extended by OpenAxiom $as_me 1.1.0-2007-12-11, which was
 generated by GNU Autoconf 2.60.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -25252,7 +25252,7 @@ Report bugs to <bug-autoconf@gnu.org>."
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF
 ac_cs_version="\\
-OpenAxiom config.status 1.1.0-2007-12-09
+OpenAxiom config.status 1.1.0-2007-12-11
 configured by $0, generated by GNU Autoconf 2.60,
   with options \\"`echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"
 
diff --git a/configure.ac b/configure.ac
index 6c388747..88ab4631 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,6 @@
 sinclude(config/open-axiom.m4)
 sinclude(config/aclocal.m4)
-AC_INIT([OpenAxiom], [1.1.0-2007-12-09], 
+AC_INIT([OpenAxiom], [1.1.0-2007-12-11], 
         [open-axiom-bugs@lists.sf.net])
 
 AC_CONFIG_AUX_DIR(config)
diff --git a/configure.ac.pamphlet b/configure.ac.pamphlet
index b8af29ab..8d7a81a7 100644
--- a/configure.ac.pamphlet
+++ b/configure.ac.pamphlet
@@ -1010,7 +1010,7 @@ information:
 <<Autoconf init>>=
 sinclude(config/open-axiom.m4)
 sinclude(config/aclocal.m4)
-AC_INIT([OpenAxiom], [1.1.0-2007-12-09], 
+AC_INIT([OpenAxiom], [1.1.0-2007-12-11], 
         [open-axiom-bugs@lists.sf.net])
 
 @
diff --git a/src/algebra/ChangeLog b/src/algebra/ChangeLog
index 278e4ff3..3fd7f05d 100644
--- a/src/algebra/ChangeLog
+++ b/src/algebra/ChangeLog
@@ -1,3 +1,7 @@
+2007-12-11  Gabriel Dos Reis  <gdr@cs.tamu.edu>
+
+	* syntax.spad (nil?$Syntax): New predicate.
+
 2007-12-06  Gabriel Dos Reis  <gdr@cs.tamu.edu>
 
 	* syntax.spad (Syntax): Add explicit conversion functions from 
diff --git a/src/algebra/syntax.spad b/src/algebra/syntax.spad
index 80bee21e..df62adb5 100644
--- a/src/algebra/syntax.spad
+++ b/src/algebra/syntax.spad
@@ -83,6 +83,9 @@ Syntax(): Public == Private where
     buildSyntax: (%, List %) -> %
       ++ buildSyntax(op, [a1, ..., an]) builds a syntax object for op(a1,...,an).
 
+    nil?: % -> Boolean
+      ++ nil?(s) is true when `s' is a syntax for the constant nil.
+
     getOperator: % -> Union(Integer, DoubleFloat, Symbol, String, %)
       ++ getOperator(x) returns the operator, or tag, of the syntax `x'.
       ++ The return value is itself a syntax if `x' really is an 
@@ -147,6 +150,9 @@ Syntax(): Public == Private where
     buildSyntax(op: %, l: List %): % ==
       cons(op, l) pretend %
 
+    nil? x ==
+      null? rep x
+
     getOperator x ==
       atom? rep x => userError "atom as operand to getOperator"
       s := car rep x