/** For each node, update the block stack and reference collection as appropriate. */
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isName()
|| n.isRest()
|| (n.isStringKey() && parent.isObjectPattern() && !n.hasChildren())) {
Var v;
if (n.getString().equals("arguments")) {
v = t.getScope().getArgumentsVar();
} else {
v = t.getScope().getVar(n.getString());
}
if (v != null) {
if (varFilter.apply(v)) {
addReference(v, new Reference(n, t, peek(blockStack)));
}
if (v.getParentNode() != null
&& NodeUtil.isHoistedFunctionDeclaration(v.getParentNode())
&&
// If we're only traversing a narrow scope, do not try to climb outside.
(narrowScope == null || narrowScope.getDepth() <= v.getScope().getDepth())) {
outOfBandTraversal(v);
}
}
}
if (isBlockBoundary(n, parent)) {
pop(blockStack);
}
}
/** @return The first property in the objlit that matches the key. */
private static Node extractProperty(Node objlit, String keyName) {
for (Node keyNode : objlit.children()) {
if (keyNode.getString().equals(keyName)) {
return keyNode.isStringKey() ? keyNode.getFirstChild() : null;
}
}
return null;
}
// Only unquoted plain properties are currently supported.
private static boolean validateObjLit(Node objlit) {
for (Node key : objlit.children()) {
if (!key.isStringKey() || key.isQuotedString()) {
return false;
}
}
return true;
}
private boolean hasShorthandAssignment(Node objLit) {
Preconditions.checkState(objLit.isObjectLit());
for (Node property : objLit.children()) {
if (property.isStringKey() && !property.hasChildren()) {
return true;
}
}
return false;
}
private boolean isContainedInGoogDefineClass(Node n) {
while (n != null) {
n = n.getParent();
if (n.isCall()) {
if (isGoogDefineClass(n)) {
return true;
}
} else if (!n.isObjectLit() && !n.isStringKey()) {
break;
}
}
return false;
}
private void validateObjectPattern(int type, Node n) {
validateNodeType(Token.OBJECT_PATTERN, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
// When the object pattern is a direct child of a var/let/const node,
// the last element is the RHS of the assignment.
if (c == n.getLastChild() && NodeUtil.isNameDeclaration(n.getParent())) {
validateExpression(c);
} else if (c.isStringKey()) {
validateObjectPatternStringKey(type, c);
} else {
// Nested destructuring pattern.
validateNameDeclarationChild(type, c);
}
}
}
/**
* @return A list of functions from a behavior which should be copied to the element prototype.
*/
private List<MemberDefinition> getBehaviorFunctionsToCopy(Node behaviorObjLit) {
Preconditions.checkState(behaviorObjLit.isObjectLit());
ImmutableList.Builder<MemberDefinition> functionsToCopy = ImmutableList.builder();
for (Node keyNode : behaviorObjLit.children()) {
if ((keyNode.isStringKey() && keyNode.getFirstChild().isFunction()
|| keyNode.isMemberFunctionDef())
&& !behaviorNamesNotToCopy.contains(keyNode.getString())) {
functionsToCopy.add(
new MemberDefinition(
NodeUtil.getBestJSDocInfo(keyNode), keyNode, keyNode.getFirstChild()));
}
}
return functionsToCopy.build();
}
private static boolean isDeclarationHelper(Node node) {
Node parent = node.getParent();
// Special case for class B extends A, A is not a declaration.
if (parent.isClass() && node != parent.getFirstChild()) {
return false;
}
// This condition can be true during InlineVariables.
if (parent.getParent() == null) {
return false;
}
if (NodeUtil.isNameDeclaration(parent.getParent()) && node == parent.getLastChild()) {
// Unless it is something like "for (var/let/const a of x){}",
// this is the RHS of a var/let/const and thus not a declaration.
if (parent.getParent().getParent() == null || !parent.getParent().getParent().isForOf()) {
return false;
}
}
// Special cases for destructuring patterns.
if (parent.isDestructuringPattern()
|| (parent.isStringKey() && parent.getParent().isObjectPattern())
|| (parent.isComputedProp()
&& parent.getParent().isObjectPattern()
&& node == parent.getLastChild())
|| (parent.isDefaultValue() && node == parent.getFirstChild())) {
return isDeclarationHelper(parent);
}
// Special case for arrow function
if (parent.isArrowFunction()) {
return node == parent.getFirstChild();
}
return DECLARATION_PARENTS.contains(parent.getType());
}
private void visitArrayPattern(NodeTraversal t, Node arrayPattern, Node parent) {
Node rhs, nodeToDetach;
if (NodeUtil.isNameDeclaration(parent) && !NodeUtil.isEnhancedFor(parent.getParent())) {
// The array pattern is the only child, because Es6SplitVariableDeclarations
// has already run.
Preconditions.checkState(arrayPattern.getNext() == null);
rhs = arrayPattern.getLastChild();
nodeToDetach = parent;
} else if (parent.isAssign()) {
rhs = arrayPattern.getNext();
nodeToDetach = parent.getParent();
Preconditions.checkState(nodeToDetach.isExprResult());
} else if (parent.isArrayPattern() || parent.isDefaultValue() || parent.isStringKey()) {
// This is a nested array pattern. Don't do anything now; we'll visit it
// after visiting the parent.
return;
} else if (NodeUtil.isEnhancedFor(parent) || NodeUtil.isEnhancedFor(parent.getParent())) {
visitDestructuringPatternInEnhancedFor(arrayPattern);
return;
} else {
Preconditions.checkState(parent.isCatch() || parent.isForOf());
cannotConvertYet(
arrayPattern, "ARRAY_PATTERN that is a child of a " + Token.name(parent.getType()));
return;
}
// Convert 'var [x, y] = rhs' to:
// var temp = rhs;
// var x = temp[0];
// var y = temp[1];
String tempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
Node tempDecl =
IR.var(IR.name(tempVarName), rhs.detachFromParent())
.useSourceInfoIfMissingFromForTree(arrayPattern);
nodeToDetach.getParent().addChildBefore(tempDecl, nodeToDetach);
int i = 0;
for (Node child = arrayPattern.getFirstChild(), next; child != null; child = next, i++) {
next = child.getNext();
if (child.isEmpty()) {
continue;
}
Node newLHS, newRHS;
if (child.isDefaultValue()) {
Node getElem = IR.getelem(IR.name(tempVarName), IR.number(i));
// [x = defaultValue] = rhs;
// becomes
// var temp = rhs;
// x = (temp[0] === undefined) ? defaultValue : temp[0];
newLHS = child.getFirstChild().detachFromParent();
newRHS = defaultValueHook(getElem, child.getLastChild().detachFromParent());
} else if (child.isRest()) {
newLHS = child.detachFromParent();
newLHS.setType(Token.NAME);
// [].slice.call(temp, i)
newRHS =
IR.call(
IR.getprop(IR.getprop(IR.arraylit(), IR.string("slice")), IR.string("call")),
IR.name(tempVarName),
IR.number(i));
} else {
newLHS = child.detachFromParent();
newRHS = IR.getelem(IR.name(tempVarName), IR.number(i));
}
Node newNode;
if (parent.isAssign()) {
Node assignment = IR.assign(newLHS, newRHS);
newNode = IR.exprResult(assignment);
} else {
newNode = IR.declaration(newLHS, newRHS, parent.getType());
}
newNode.useSourceInfoIfMissingFromForTree(arrayPattern);
nodeToDetach.getParent().addChildBefore(newNode, nodeToDetach);
// Explicitly visit the LHS of the new node since it may be a nested
// destructuring pattern.
visit(t, newLHS, newLHS.getParent());
}
nodeToDetach.detachFromParent();
compiler.reportCodeChange();
}
private void visitObjectPattern(NodeTraversal t, Node objectPattern, Node parent) {
Node rhs, nodeToDetach;
if (NodeUtil.isNameDeclaration(parent) && !NodeUtil.isEnhancedFor(parent.getParent())) {
rhs = objectPattern.getLastChild();
nodeToDetach = parent;
} else if (parent.isAssign() && parent.getParent().isExprResult()) {
rhs = parent.getLastChild();
nodeToDetach = parent.getParent();
} else if (parent.isStringKey() || parent.isArrayPattern() || parent.isDefaultValue()) {
// Nested object pattern; do nothing. We will visit it after rewriting the parent.
return;
} else if (NodeUtil.isEnhancedFor(parent) || NodeUtil.isEnhancedFor(parent.getParent())) {
visitDestructuringPatternInEnhancedFor(objectPattern);
return;
} else {
Preconditions.checkState(parent.isCatch(), parent);
cannotConvertYet(
objectPattern, "OBJECT_PATTERN that is a child of a " + Token.name(parent.getType()));
return;
}
// Convert 'var {a: b, c: d} = rhs' to:
// var temp = rhs;
// var b = temp.a;
// var d = temp.c;
String tempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
Node tempDecl =
IR.var(IR.name(tempVarName), rhs.detachFromParent())
.useSourceInfoIfMissingFromForTree(objectPattern);
nodeToDetach.getParent().addChildBefore(tempDecl, nodeToDetach);
for (Node child = objectPattern.getFirstChild(), next; child != null; child = next) {
next = child.getNext();
Node newLHS, newRHS;
if (child.isStringKey()) {
Preconditions.checkState(child.hasChildren());
Node getprop =
new Node(
child.isQuotedString() ? Token.GETELEM : Token.GETPROP,
IR.name(tempVarName),
IR.string(child.getString()));
Node value = child.removeFirstChild();
if (!value.isDefaultValue()) {
newLHS = value;
newRHS = getprop;
} else {
newLHS = value.removeFirstChild();
Node defaultValue = value.removeFirstChild();
newRHS = defaultValueHook(getprop, defaultValue);
}
} else if (child.isComputedProp()) {
if (child.getLastChild().isDefaultValue()) {
newLHS = child.getLastChild().removeFirstChild();
Node getelem = IR.getelem(IR.name(tempVarName), child.removeFirstChild());
String intermediateTempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
Node intermediateDecl = IR.var(IR.name(intermediateTempVarName), getelem);
intermediateDecl.useSourceInfoIfMissingFromForTree(child);
nodeToDetach.getParent().addChildBefore(intermediateDecl, nodeToDetach);
newRHS =
defaultValueHook(
IR.name(intermediateTempVarName), child.getLastChild().removeFirstChild());
} else {
newRHS = IR.getelem(IR.name(tempVarName), child.removeFirstChild());
newLHS = child.removeFirstChild();
}
} else if (child.isDefaultValue()) {
newLHS = child.removeFirstChild();
Node defaultValue = child.removeFirstChild();
Node getprop = IR.getprop(IR.name(tempVarName), IR.string(newLHS.getString()));
newRHS = defaultValueHook(getprop, defaultValue);
} else {
throw new IllegalStateException("Unexpected OBJECT_PATTERN child: " + child);
}
Node newNode;
if (NodeUtil.isNameDeclaration(parent)) {
newNode = IR.declaration(newLHS, newRHS, parent.getType());
} else if (parent.isAssign()) {
newNode = IR.exprResult(IR.assign(newLHS, newRHS));
} else {
throw new IllegalStateException("not reached");
}
newNode.useSourceInfoIfMissingFromForTree(child);
nodeToDetach.getParent().addChildBefore(newNode, nodeToDetach);
// Explicitly visit the LHS of the new node since it may be a nested
// destructuring pattern.
visit(t, newLHS, newLHS.getParent());
}
nodeToDetach.detachFromParent();
compiler.reportCodeChange();
}