From abe9f20a8580c32db26fc902883343839fd39b90 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Santos=20Costa?= <vsc@dcc.fc.up.pt>
Date: Sun, 20 Jan 2013 23:15:09 +0000
Subject: [PATCH] depth limit cn go to infinity

---
 C/arith1.c      |  3 +--
 C/depth_bound.c | 22 +++++++++++++++++++---
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/C/arith1.c b/C/arith1.c
index 86c9b8379..9b7ac7dc5 100644
--- a/C/arith1.c
+++ b/C/arith1.c
@@ -523,8 +523,7 @@ eval1(Int fi, Term t) {
 #endif
 #if HAVE_ISINF
       if (isinf(dbl)) {
-	return Yap_ArithError(EVALUATION_ERROR_INT_OVERFLOW, MkFloatTerm(dbl), "integer\
-(%f)",dbl);
+	return Yap_ArithError(EVALUATION_ERROR_INT_OVERFLOW, MkFloatTerm(dbl), "integer (%f)",dbl);
       }
 #endif
       if (dbl < 0.0)
diff --git a/C/depth_bound.c b/C/depth_bound.c
index cf56a392a..b29558366 100644
--- a/C/depth_bound.c
+++ b/C/depth_bound.c
@@ -18,6 +18,11 @@
 static char     SccsId[] = "%W% %G%";
 #endif /* SCCS */
 
+#include <math.h>
+#ifndef INFINITY
+#define INFINITY (1.0/0.0)
+#endif
+
 #include "Yap.h"
 
 #ifdef DEPTH_LIMIT
@@ -29,7 +34,10 @@ STD_PROTO(static Int p_set_depth_limit, ( USES_REGS1 ));
 
 static Int p_get_depth_limit( USES_REGS1 )
 {
-  return(Yap_unify_constant(ARG1, MkIntTerm(IntOfTerm(DEPTH/2))));
+  Int d = IntOfTerm(DEPTH);
+  if (d % 2 == 1) 
+    return(Yap_unify(ARG1, MkFloatTerm(INFINITY)));
+  return(Yap_unify_constant(ARG1, MkIntTerm(d/2)));
 }
 
 static Int p_set_depth_limit( USES_REGS1 )
@@ -40,8 +48,12 @@ static Int p_set_depth_limit( USES_REGS1 )
     Yap_Error(INSTANTIATION_ERROR, d, "set-depth_limit");
     return(FALSE);
   } else if (!IsIntegerTerm(d)) {
-    Yap_Error(TYPE_ERROR_INTEGER, d, "set-depth_limit");
-    return(FALSE);
+    if (IsFloatTerm(d) && isinf(FloatOfTerm(d))) {
+      d = RESET_DEPTH();
+    } else {
+      Yap_Error(TYPE_ERROR_INTEGER, d, "set-depth_limit");
+      return(FALSE);
+    }
   }
   d = MkIntTerm(IntegerOfTerm(d)*2);
 
@@ -59,6 +71,10 @@ static Int p_set_depth_limit_for_next_call( USES_REGS1 )
     Yap_Error(INSTANTIATION_ERROR, d, "set-depth_limit");
     return(FALSE);
   } else if (!IsIntegerTerm(d)) {
+    if (IsFloatTerm(d) && isinf(FloatOfTerm(d))) {
+      DEPTH = RESET_DEPTH();
+      return TRUE;
+    }
     Yap_Error(TYPE_ERROR_INTEGER, d, "set-depth_limit");
     return(FALSE);
   }