[PPL-devel] [GIT] ppl/ppl(master): Added Prolog_get_nil() and Prolog_put_nil().

[Roberto Bagnara]

Module: ppl/ppl
Branch: master
Commit: e24eb663ed59187529cabc314f77c2623af08c16
URL:    http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=e24eb663ed59187529cabc314f77c2623af08c16

Author: Roberto Bagnara <roberto.bagnara at bugseng.com>
Date:   Sat Mar 29 10:20:25 2014 +0100

Added Prolog_get_nil() and Prolog_put_nil().

---

 interfaces/Prolog/XSB/xsb_cfli.hh |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/interfaces/Prolog/XSB/xsb_cfli.hh b/interfaces/Prolog/XSB/xsb_cfli.hh
index 4032f06..1acdb52 100644
--- a/interfaces/Prolog/XSB/xsb_cfli.hh
+++ b/interfaces/Prolog/XSB/xsb_cfli.hh
@@ -93,6 +93,16 @@ Prolog_put_ulong(Prolog_term_ref& t, unsigned long ul) {
 }
 
 /*!
+  Assign to \p t the list terminator <CODE>[]</CODE> (which needs not
+  be an atom).
+*/
+inline int
+Prolog_put_nil(Prolog_term_ref& t) {
+  assert(is_var(t) == TRUE);
+  return c2p_nil(t) != FALSE;
+}
+
+/*!
   Assign to \p t an atom whose name is given
   by the null-terminated string \p s.
 */
@@ -325,6 +335,15 @@ Prolog_get_arg(int i, Prolog_term_ref t, Prolog_term_ref& a) {
 }
 
 /*!
+  Succeeds if and only if \p t represents the list terminator <CODE>[]</CODE>
+  (which needs not be an atom).
+*/
+inline int
+Prolog_get_nil(Prolog_term_ref t) {
+  return is_nil(t) != FALSE;
+}
+
+/*!
   If \p c is a Prolog cons (list constructor), assign its head and
   tail to \p h and \p t, respectively.
   The behavior is undefined if \p c is not a Prolog cons.