diogo/yap-6.3
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boot

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This commit is contained in:
Vitor Santos Costa
2019-01-31 11:54:17 +00:00
parent f7ed109d1c
commit b71b4f6fca
8 changed files with 72 additions and 31 deletions
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33
C/exec.c
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@@ -189,11 +189,10 @@ static bool CallError(yap_error_number err, Term t, Term mod USES_REGS) {
/** @pred current_choice_point( -CP )
*
* unify the logic variable _CP_ with a number that gives the offset of the
* current choice-point. This number is only valid as long as we do not
*backtrack by or cut
* _CP_, and is safe in the presence of stack shifting and/or garbage
*collection.
* unify the logic variable _CP_ with a number that identifies the
* last alternative taken, or current choice-point. This number is
* only valid as long as we do not backtrack by or cut _CP_, and is
* safe in the presence of stack shifting and/or garbage collection.
*/
static Int current_choice_point(USES_REGS1) {
Term t = Deref(ARG1);
@@ -208,6 +207,29 @@ static Int current_choice_point(USES_REGS1) {
return TRUE;
}
/** @pred parent_choice_point( +CP, -PCP )
*
* given that _CP_ identifies an
* alternative taken, or choice-point, _PCP_ identifies its parent.
*
* The call will fail if _CP_ is topmost in the search tree.
*/
static Int parent_choice_point(USES_REGS1) {
Term t = Deref(ARG1);
Term td;
#if SHADOW_HB
register CELL *HBREG = HB;
#endif
if (!IsVarTerm(t))
return (FALSE);
choiceptr cp = cp_from_integer(t);
if (cp == NULL || cp->cp_b == NULL)
return false;
td = cp_as_integer(cp->cp_b PASS_REGS);
YapBind((CELL *)t, td);
return TRUE;
}
static Int save_env_b(USES_REGS1) {
Term t = Deref(ARG1);
Term td;
@@ -2302,6 +2324,7 @@ void Yap_InitExecFs(void) {
Yap_InitCPred("current_choice_point", 1, current_choice_point, 0);
Yap_InitCPred("current_choicepoint", 1, current_choice_point, 0);
Yap_InitCPred("env_choice_point", 1, save_env_b, 0);
Yap_InitCPred("parent_choice_point", 1, parent_choice_point, 0);
Yap_InitCPred("cut_at", 1, clean_ifcp, SafePredFlag);
CurrentModule = cm;
Yap_InitCPred("$restore_regs", 1, restore_regs,