globle struct lhsParseNode *GetExpressionVarConstraints(
struct lhsParseNode *theExpression)
{
struct lhsParseNode *list1 = NULL, *list2;
for (; theExpression != NULL; theExpression = theExpression->bottom)
{
if (theExpression->right != NULL)
{
list2 = GetExpressionVarConstraints(theExpression->right);
list1 = AddToVariableConstraints(list2,list1);
}
if (theExpression->type == SF_VARIABLE)
{
list2 = GetLHSParseNode();
if (theExpression->referringNode != NULL)
{ list2->type = theExpression->referringNode->type; }
else
{ list2->type = SF_VARIABLE; }
list2->value = theExpression->value;
list2->derivedConstraints = TRUE;
list2->constraints = CopyConstraintRecord(theExpression->constraints);
list1 = AddToVariableConstraints(list2,list1);
}
}
return(list1);
}
globle struct lhsParseNode *DeriveVariableConstraints(
void *theEnv,
struct lhsParseNode *theNode)
{
struct lhsParseNode *orNode, *andNode;
struct lhsParseNode *list1, *list2, *list3 = NULL;
int first = TRUE;
/*===============================*/
/* Process the constraints for a */
/* single connected constraint. */
/*===============================*/
for (orNode = theNode->bottom; orNode != NULL; orNode = orNode->bottom)
{
/*=================================================*/
/* Intersect all of the &'ed constraints together. */
/*=================================================*/
list2 = NULL;
for (andNode = orNode; andNode != NULL; andNode = andNode->right)
{
if ((andNode->type == RETURN_VALUE_CONSTRAINT) ||
(andNode->type == PREDICATE_CONSTRAINT))
{
list1 = GetExpressionVarConstraints(theEnv,andNode->expression);
list2 = AddToVariableConstraints(theEnv,list2,list1);
}
}
if (first)
{
list3 = list2;
first = FALSE;
}
else
{ list3 = UnionVariableConstraints(theEnv,list3,list2); }
}
return(list3);
}
