PT_Tree PT_findTreeParentRecursive(PT_Tree needle, PT_Tree haystack)
{
assert(needle != NULL);
assert(haystack != NULL);
assert(needle != haystack);
if (ATtableGet(findParentCache, PT_TreeToTerm(haystack)) != NULL) {
return NULL;
}
if (PT_hasTreeArgs(haystack)) {
PT_Args children = PT_getTreeArgs(haystack);
while (!PT_isArgsEmpty(children)) {
PT_Tree child = PT_getArgsHead(children);
if (PT_isEqualTree(child, needle)) {
return haystack;
}
else {
PT_Tree suspect = PT_findTreeParentRecursive(needle, child);
if (suspect != NULL) {
return suspect;
}
}
children = PT_getArgsTail(children);
}
}
ATtablePut(findParentCache, PT_TreeToTerm(haystack), PT_TreeToTerm(NeedleNotHere));
return NULL;
}
ATbool PT_containsTreeCycle(PT_Tree tree) {
if (PT_isTreeCycle(tree)) {
return ATtrue;
}
if (PT_hasTreeArgs(tree)) {
return PT_containsArgsCycle(PT_getTreeArgs(tree));
}
return ATfalse;
}
static PT_Tree pTreeWithSymbol(PT_Tree tree, int *i, PT_Symbol sym, SDF_Symbol ssym)
{
if (PT_isSymbolSort(sym)) {
return pTree(tree, i);
}
else if (PT_isSymbolLit(sym)) {
return tree;
}
else if (PT_isSymbolIterStar(sym) || PT_isSymbolIterPlus(sym)) {
return pList(tree, i, ssym);
}
else if (PT_isSymbolIterStarSep(sym) || PT_isSymbolIterPlusSep(sym)) {
return pSepList(tree, i, ssym);
}
/* the rest is handled by doing nothing */
if (PT_hasTreeArgs(tree)) {
return PT_setTreeArgs(tree, pArgs(PT_getTreeArgs(tree), i));
}
else {
return tree;
}
}
