Java Node.getFirstChild方法代码示例

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Reduce "return undefined" or "return void 0" to simply "return".
 */
private void tryReduceReturn(NodeTraversal t, Node n) {
  Node result = n.getFirstChild();
  if (result != null) {
    switch (result.getType()) {
      case Token.VOID:
        Node operand = result.getFirstChild();
        if (!NodeUtil.mayHaveSideEffects(operand)) {
          n.removeFirstChild();
          t.getCompiler().reportCodeChange();
        }
        return;
      case Token.NAME:
        String name = result.getString();
        if (name.equals("undefined")) {
          n.removeFirstChild();
          t.getCompiler().reportCodeChange();
        }
        return;
    }
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
public void testLinenoCharnoArrayLiteral() throws Exception {
  Node n = parse("\n  [8, 9]").getFirstChild().getFirstChild();

  assertEquals(Token.ARRAYLIT, n.getType());
  assertEquals(2, n.getLineno());
  assertEquals(2, n.getCharno());

  n = n.getFirstChild();

  assertEquals(Token.NUMBER, n.getType());
  assertEquals(2, n.getLineno());
  assertEquals(3, n.getCharno());

  n = n.getNext();

  assertEquals(Token.NUMBER, n.getType());
  assertEquals(2, n.getLineno());
  assertEquals(6, n.getCharno());
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Determines whether a deprecation warning should be emitted.
 * @param t The current traversal.
 * @param n The node which we are checking.
 * @param parent The parent of the node which we are checking.
 */
private boolean shouldEmitDeprecationWarning(
    NodeTraversal t, Node n, Node parent) {
  // In the global scope, there are only two kinds of accesses that should
  // be flagged for warnings:
  // 1) Calls of deprecated functions and methods.
  // 2) Instantiations of deprecated classes.
  // For now, we just let everything else by.
  if (t.inGlobalScope()) {
    if (!((parent.getType() == Token.CALL && parent.getFirstChild() == n) ||
            n.getType() == Token.NEW)) {
      return false;
    }
  }

  // We can always assign to a deprecated property, to keep it up to date.
  if (n.getType() == Token.GETPROP && n == parent.getFirstChild() &&
      NodeUtil.isAssignmentOp(parent)) {
    return false;
  }

  return !canAccessDeprecatedTypes(t);
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
@Override
public Collection<Definition> getDefinitionsReferencedAt(Node useSite) {
  if (definitionSiteMap.containsKey(useSite)) {
    return null;
  }

  if (NodeUtil.isGetProp(useSite)) {
    String propName = useSite.getLastChild().getString();
    if (propName.equals("apply") || propName.equals("call")) {
      useSite = useSite.getFirstChild();
    }
  }

  String name = getSimplifiedName(useSite);
  if (name != null) {
    Collection<Definition> defs = nameDefinitionMultimap.get(name);
    if (!defs.isEmpty()) {
      return defs;
    } else {
      return null;
    }
  } else {
    return null;
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 *  For all VAR node with uninitialized declarations, set
 *  the values to be "undefined".
 */
private void fixUnitializedVarDeclarations(Node n) {
  // Inner loop structure must already have logic to initialize its
  // variables.  In particular FOR-IN structures must not be modified.
  if (NodeUtil.isLoopStructure(n)) {
    return;
  }

  // For all VARs
  if (NodeUtil.isVar(n)) {
    Node name = n.getFirstChild();
    // It isn't initialized.
    if (!name.hasChildren()) {
      name.addChildToBack(NodeUtil.newUndefinedNode());
    }
    return;
  }

  for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
    fixUnitializedVarDeclarations(c);
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Does the given node define one of our aliases?
 */
private boolean isAliasDefinition(Node n) {
  if (n.getType() != Token.NAME) {
    return false;
  }

  if (!isAliasName(n.getString())) {
    // The given Node's string contents is not an alias. Skip it.
    return false;
  }

  /*
   * A definition must have a child node (otherwise it's just a
   * reference to the alias).
   */
  return n.getFirstChild() != null;
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Eliminates any object literal keys in an object literal declaration that
 * have strip names.
 *
 * @param t The traversal
 * @param n An OBJLIT node
 */
void eliminateKeysWithStripNamesFromObjLit(NodeTraversal t, Node n) {
  // OBJLIT
  //   key1
  //   value1
  //   ...
  Node key = n.getFirstChild();
  while (key != null) {
    if (key.getType() == Token.STRING &&
        isStripName(key.getString())) {
      Node value = key.getNext();
      Node next = value.getNext();
      n.removeChild(key);
      n.removeChild(value);
      key = next;
      compiler.reportCodeChange();
    } else {
      key = key.getNext().getNext();
    }
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
private void replaceAccessor(Node getPropNode) {
  /*
   *  BEFORE
      getprop
          NODE...
          string length
      AFTER
      getelem
          NODE...
          name PROP_length
   */
  Node propNameNode = getPropNode.getLastChild();
  String propName = propNameNode.getString();
  if (props.get(propName).aliasAccessor) {
    Node propSrc = getPropNode.getFirstChild();
    getPropNode.removeChild(propSrc);

    Node newNameNode =
      Node.newString(Token.NAME, getArrayNotationNameFor(propName));

    Node elemNode = new Node(Token.GETELEM, propSrc, newNameNode);
    replaceNode(getPropNode.getParent(), getPropNode, elemNode);

    compiler.reportCodeChange();
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * @return Whether the predicate is true for the node or any of its children.
 */
static boolean has(Node node,
                   Predicate<Node> pred,
                   Predicate<Node> traverseChildrenPred) {
  if (pred.apply(node)) {
    return true;
  }

  if (!traverseChildrenPred.apply(node)) {
    return false;
  }

  for (Node c = node.getFirstChild(); c != null; c = c.getNext()) {
    if (has(c, pred, traverseChildrenPred)) {
      return true;
    }
  }

  return false;
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
public void testMergeBlock2() {
  Compiler compiler = new Compiler();

  // Test removing the initializer.
  Node actual = parse("foo:{a();}");

  Node parentLabel = actual.getFirstChild();
  Node childBlock = parentLabel.getLastChild();

  assertTrue(NodeUtil.tryMergeBlock(childBlock));
  String expected = "foo:a();";
  String difference = parse(expected).checkTreeEquals(actual);
  assertNull("Nodes do not match:\n" + difference, difference);
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
public void testFunctionParamLocation() {
  Node root = newParse(
      "\nfunction\n" +
      "     foo(a,\n" +
      "     b,\n" +
      "     c)\n" +
      "{}\n");

  Node function = root.getFirstChild();
  Node functionName = function.getFirstChild();
  Node params = functionName.getNext();
  Node param1 = params.getFirstChild();
  Node param2 = param1.getNext();
  Node param3 = param2.getNext();
  Node body = params.getNext();

  assertNodePosition(2, 5, function);
  assertNodePosition(2, 5, functionName);
  // params corresponds to the LP token.
  // Can't be on a separate line because of inferred
  // semicolons.
  assertNodePosition(2, 8, params);
  assertNodePosition(2, 9, param1);
  assertNodePosition(3, 5, param2);
  assertNodePosition(4, 5, param3);
  assertNodePosition(5, 0, body);
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Returns an action for assigning the right-hand-side to the left or null
 * if this assignment should be ignored.
 */
private List<Action> createAssignmentActions(
    Node lhs, Node rhs, Node parent) {
  switch (lhs.getType()) {
    case Token.NAME:
      ConcreteSlot var = (ConcreteSlot) scope.getSlot(lhs.getString());
      Preconditions.checkState(var != null,
          "Type tightener could not find variable with name %s",
          lhs.getString());
      return Lists.<Action>newArrayList(
          new VariableAssignAction(var, rhs));

    case Token.GETPROP:
      Node receiver = lhs.getFirstChild();
      return Lists.<Action>newArrayList(
          new PropertyAssignAction(receiver, rhs));

    case Token.GETELEM:
      return Lists.newArrayList();

    case Token.GET_REF:
      // We ignore ref specials as their types should not be computed.
      if (lhs.getFirstChild().getType() == Token.REF_SPECIAL) {
        return Lists.newArrayList();
      } else {
        throw new AssertionError(
            "Bad LHS for getref: " + parent.toStringTree());
      }

    default:
      throw new AssertionError(
          "Bad LHS for assignment: " + parent.toStringTree());
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
public void visit(NodeTraversal t, Node n, Node parent) {
  if (n.getType() == Token.FUNCTION) {
    Node functionNameNode = n.getFirstChild();
    String functionName = functionNameNode.getString();

    Node enclosingFunction = t.getEnclosingFunction();

    functionMap.put(n,
        new FunctionRecord(nextId, enclosingFunction, functionName));
    nextId++;
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Replaces a member declaration to an assignment to the temp prototype
 * object.
 */
private void replacePrototypeMemberDeclaration(
    PrototypeMemberDeclaration declar) {
  // x.prototype.y = ...  ->  t.y = ...
  Node assignment = declar.node.getFirstChild();
  Node lhs = assignment.getFirstChild();
  Node name = NodeUtil.newQualifiedNameNode(
      prototypeAlias + "." + declar.memberName, declar.node,
      declar.memberName);

  // Save the full prototype path on the left hand side of the assignment
  // for debugging purposes.
  // declar.lhs = x.prototype.y so first child of the first child
  // is 'x'.
  Node accessNode = declar.lhs.getFirstChild().getFirstChild();
  Object originalName = accessNode.getProp(Node.ORIGINALNAME_PROP);

  String className = "?";

  if (originalName != null) {
    className = originalName.toString();
  }

  NodeUtil.setDebugInformation(name.getFirstChild(), lhs,
                               className + ".prototype");

  assignment.replaceChild(lhs, name);
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
public void testLinenoCharnoObjectLiteral() throws Exception {
  Node n = parse("\n\n var a = {a:0\n,b :1};")
      .getFirstChild().getFirstChild().getFirstChild();

  assertEquals(Token.OBJECTLIT, n.getType());
  assertEquals(3, n.getLineno());
  assertEquals(9, n.getCharno());

  n = n.getFirstChild();

  assertEquals(Token.STRING, n.getType());
  assertEquals(3, n.getLineno());
  assertEquals(10, n.getCharno());

  n = n.getNext();

  assertEquals(Token.NUMBER, n.getType());
  assertEquals(3, n.getLineno());
  assertEquals(12, n.getCharno());

  n = n.getNext();

  assertEquals(Token.STRING, n.getType());
  assertEquals(4, n.getLineno());
  assertEquals(1, n.getCharno());

  n = n.getNext();

  assertEquals(Token.NUMBER, n.getType());
  assertEquals(4, n.getLineno());
  assertEquals(4, n.getCharno());
}