/** Add a child to the tree t. If child is a flat tree (a list), make all
* in list children of t. Warning: if t has no children, but child does
* and child isNilNode then it is ok to move children to t via
* t.children = child.children; i.e., without copying the array. This
* is for construction and I'm not sure it's completely general for
* a tree's addChild method to work this way. Make sure you differentiate
* between your tree's addChild and this parser tree construction addChild
* if it's not ok to move children to t with a simple assignment.
*/
static void
addChild (pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_TREE t, pANTLR3_BASE_TREE child)
{
if (t != NULL && child != NULL)
{
t->addChild(t, child);
}
}
static void
dbgAddChild (pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_TREE t, pANTLR3_BASE_TREE child)
{
if (t != NULL && child != NULL)
{
t->addChild(t, child);
adaptor->debugger->addChild(adaptor->debugger, t, child);
}
}
/// Add all elements of the supplied list as children of this node
///
static void
addChildren (pANTLR3_BASE_TREE tree, pANTLR3_LIST kids)
{
ANTLR3_UINT32 i;
ANTLR3_UINT32 s;
s = kids->size(kids);
for (i = 0; i<s; i++)
{
tree->addChild(tree, (pANTLR3_BASE_TREE)(kids->get(kids, i+1)));
}
}
/** If oldRoot is a nil root, just copy or move the children to newRoot.
* If not a nil root, make oldRoot a child of newRoot.
*
* \code
* old=^(nil a b c), new=r yields ^(r a b c)
* old=^(a b c), new=r yields ^(r ^(a b c))
* \endcode
*
* If newRoot is a nil-rooted single child tree, use the single
* child as the new root node.
*
* \code
* old=^(nil a b c), new=^(nil r) yields ^(r a b c)
* old=^(a b c), new=^(nil r) yields ^(r ^(a b c))
* \endcode
*
* If oldRoot was null, it's ok, just return newRoot (even if isNilNode).
*
* \code
* old=null, new=r yields r
* old=null, new=^(nil r) yields ^(nil r)
* \endcode
*
* Return newRoot. Throw an exception if newRoot is not a
* simple node or nil root with a single child node--it must be a root
* node. If newRoot is <code>^(nil x)</endcode> return x as newRoot.
*
* Be advised that it's ok for newRoot to point at oldRoot's
* children; i.e., you don't have to copy the list. We are
* constructing these nodes so we should have this control for
* efficiency.
*/
static pANTLR3_BASE_TREE
becomeRoot (pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_TREE newRootTree, pANTLR3_BASE_TREE oldRootTree)
{
/* Protect against tree rewrites if we are in some sort of error
* state, but have tried to recover. In C we can end up with a null pointer
* for a tree that was not produced.
*/
if (newRootTree == NULL)
{
return oldRootTree;
}
/* root is just the new tree as is if there is no
* current root tree.
*/
if (oldRootTree == NULL)
{
return newRootTree;
}
/* Produce ^(nil real-node)
*/
if (newRootTree->isNilNode(newRootTree))
{
if (newRootTree->getChildCount(newRootTree) > 1)
{
/* TODO: Handle tree exceptions
*/
ANTLR3_FPRINTF(stderr, "More than one node as root! TODO: Create tree exception hndling\n");
return newRootTree;
}
/* The new root is the first child
*/
newRootTree = newRootTree->getChild(newRootTree, 0);
}
/* Add old root into new root. addChild takes care of the case where oldRoot
* is a flat list (nill rooted tree). All children of oldroot are added to
* new root.
*/
newRootTree->addChild(newRootTree, oldRootTree);
/* Always returns new root structure
*/
return newRootTree;
}
/** If oldRoot is a nil root, just copy or move the children to newRoot.
* If not a nil root, make oldRoot a child of newRoot.
*
* \code
* old=^(nil a b c), new=r yields ^(r a b c)
* old=^(a b c), new=r yields ^(r ^(a b c))
* \endcode
*
* If newRoot is a nil-rooted single child tree, use the single
* child as the new root node.
*
* \code
* old=^(nil a b c), new=^(nil r) yields ^(r a b c)
* old=^(a b c), new=^(nil r) yields ^(r ^(a b c))
* \endcode
*
* If oldRoot was null, it's ok, just return newRoot (even if isNilNode).
*
* \code
* old=null, new=r yields r
* old=null, new=^(nil r) yields ^(nil r)
* \endcode
*
* Return newRoot. Throw an exception if newRoot is not a
* simple node or nil root with a single child node--it must be a root
* node. If newRoot is <code>^(nil x)</endcode> return x as newRoot.
*
* Be advised that it's ok for newRoot to point at oldRoot's
* children; i.e., you don't have to copy the list. We are
* constructing these nodes so we should have this control for
* efficiency.
*/
static pANTLR3_BASE_TREE
becomeRoot (pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_TREE newRootTree, pANTLR3_BASE_TREE oldRootTree)
{
pANTLR3_BASE_TREE saveRoot;
/* Protect against tree rewrites if we are in some sort of error
* state, but have tried to recover. In C we can end up with a null pointer
* for a tree that was not produced.
*/
if (newRootTree == NULL)
{
return oldRootTree;
}
/* root is just the new tree as is if there is no
* current root tree.
*/
if (oldRootTree == NULL)
{
return newRootTree;
}
/* Produce ^(nil real-node)
*/
if (newRootTree->isNilNode(newRootTree))
{
if (newRootTree->getChildCount(newRootTree) > 1)
{
/* TODO: Handle tree exceptions
*/
ANTLR3_FPRINTF(stderr, "More than one node as root! TODO: Create tree exception handling\n");
return newRootTree;
}
/* The new root is the first child, keep track of the original newRoot
* because if it was a Nil Node, then we can reuse it now.
*/
saveRoot = newRootTree;
newRootTree = (pANTLR3_BASE_TREE)newRootTree->getChild(newRootTree, 0);
// Reclaim the old nilNode()
//
saveRoot->reuse(saveRoot);
}
/* Add old root into new root. addChild takes care of the case where oldRoot
* is a flat list (nill rooted tree). All children of oldroot are added to
* new root.
*/
newRootTree->addChild(newRootTree, oldRootTree);
// If the oldroot tree was a nil node, then we know at this point
// it has become orphaned by the rewrite logic, so we tell it to do
// whatever it needs to do to be reused.
//
if (oldRootTree->isNilNode(oldRootTree))
{
// We have taken an old Root Tree and appended all its children to the new
// root. In addition though it was a nil node, which means the generated code
// will not reuse it again, so we will reclaim it here. First we want to zero out
// any pointers it was carrying around. We are just the baseTree handler so we
// don't know necessarilly know how to do this for the real node, we just ask the tree itself
// to do it.
//
oldRootTree->reuse(oldRootTree);
}
/* Always returns new root structure
*/
return newRootTree;
}
/** Add a child to the tree t. If child is a flat tree (a list), make all
* in list children of t. Warning: if t has no children, but child does
* and child isNil then it is ok to move children to t via
* t.children = child.children; i.e., without copying the array. This
* is for construction and I'm not sure it's completely general for
* a tree's addChild method to work this way. Make sure you differentiate
* between your tree's addChild and this parser tree construction addChild
* if it's not ok to move children to t with a simple assignment.
*/
static void
addChild (pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_TREE t, pANTLR3_BASE_TREE child)
{
t->addChild(t, child);
}
