Java Code Examples for com.google.javascript.rhino.Node#isDec()

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Return true if the storage node is an r-value.
 */
private static boolean storageNodeIsRValue(Node node) {
  Preconditions.checkArgument(isStorageNode(node));

  // We consider all names to be r-values unless
  // LHS of Token.ASSIGN
  // LHS of of for in expression
  // Child of VAR

  Node parent = node.getParent();

  if (storageNodeIsLValue(node)) {
    // Assume l-value is NOT an r-value
    // unless it is a non-simple assign
    // or an increment/decrement

    boolean nonSimpleAssign =
      NodeUtil.isAssignmentOp(parent) && !parent.isAssign();

    return (nonSimpleAssign
        || parent.isDec()
        || parent.isInc());
  }

  return true;
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * @return Whether the property is used in a way that prevents its removal.
 */
private boolean isPinningPropertyUse(Node n) {
  // Rather than looking for cases that are uses, we assume all references are
  // pinning uses unless they are:
  //  - a simple assignment (x.a = 1)
  //  - a compound assignment or increment (x++, x += 1) whose result is
  //    otherwise unused

  Node parent = n.getParent();
  if (n == parent.getFirstChild()) {
    if (parent.isAssign()) {
      // A simple assignment doesn't pin the property.
      return false;
    } else if (NodeUtil.isAssignmentOp(parent)
          || parent.isInc() || parent.isDec()) {
      // In general, compound assignments are both reads and writes, but
      // if the property is never otherwise read we can consider it simply
      // a write.
      // However if the assign expression is used as part of a larger
      // expression, we much consider it a read. For example:
      //    x = (y.a += 1);
      return NodeUtil.isExpressionResultUsed(parent);
    }
  }
  return true;
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

/**
 * Determines whether this node is used as an L-value. Notice that sometimes
 * names are used as both L-values and R-values.
 *
 * We treat "var x;" as a pseudo-L-value, which kind of makes sense if you
 * treat it as "assignment to 'undefined' at the top of the scope". But if
 * we're honest with ourselves, it doesn't make sense, and we only do this
 * because it makes sense to treat this as syntactically similar to
 * "var x = 0;".
 *
 * @param n The node
 * @return True if n is an L-value.
 */
public static boolean isLValue(Node n) {
  Preconditions.checkArgument(n.isName() || n.isGetProp() ||
      n.isGetElem());
  Node parent = n.getParent();
  if (parent == null) {
    return false;
  }
  return (NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || (NodeUtil.isForIn(parent) && parent.getFirstChild() == n)
      || parent.isVar()
      || (parent.isFunction() && parent.getFirstChild() == n)
      || parent.isDec()
      || parent.isInc()
      || parent.isParamList()
      || parent.isCatch();
}
 

private boolean isLValue(Node n) {
  Node parent = n.getParent();
  return (parent.isInc()
      || parent.isDec()
      || (NodeUtil.isAssignmentOp(parent)
      && parent.getFirstChild() == n));
}
 

private boolean isAssignmentTarget(Node n) {
  Node parent = n.getParent();
  if ((NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || parent.isInc()
      || parent.isDec()) {
    // If GETPROP/GETELEM is used as assignment target the object literal is
    // acting as a temporary we can't fold it here:
    //    "{a:x}.a += 1" is not "x += 1"
    return true;
  }
  return false;
}
 

private boolean isLValue(Node n) {
  Node parent = n.getParent();
  return (parent.isInc()
      || parent.isDec()
      || (NodeUtil.isAssignmentOp(parent)
      && parent.getFirstChild() == n));
}
 

private boolean isAssignmentTarget(Node n) {
  Node parent = n.getParent();
  if ((NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == n)
      || parent.isInc()
      || parent.isDec()) {
    // If GETPROP/GETELEM is used as assignment target the object literal is
    // acting as a temporary we can't fold it here:
    //    "{a:x}.a += 1" is not "x += 1"
    return true;
  }
  return false;
}
 

/**
 * Logic for when a getprop can be replaced.
 * Can't alias a call to eval per ECMA-262 spec section 15.1.2.1
 * Can't be an assign -> no a.b = c;
 * Can't be inc or dec -> no a.b++; or a.b--;
 * Must be a GETPROP (NODE, A) where A is a reserved name
 * @param propNameNode Property name node
 * @param getPropNode GETPROP node
 * @param parent parent node
 * @return True if can be replaced
 */
private boolean canReplaceWithGetProp(Node propNameNode, Node getPropNode,
      Node parent) {
  boolean isCallTarget = (parent.isCall())
      && (parent.getFirstChild() == getPropNode);
  boolean isAssignTarget = NodeUtil.isAssignmentOp(parent)
      && (parent.getFirstChild() == getPropNode);
  boolean isIncOrDec = (parent.isInc()) ||
      (parent.isDec());
  return (propNameNode.isString()) && !isAssignTarget
      && (!isCallTarget || !"eval".equals(propNameNode.getString()))
      && !isIncOrDec
      && props.containsKey(propNameNode.getString());
}
 

private boolean isLValue(Node n) {
  Node parent = n.getParent();
  return (parent.isInc()
      || parent.isDec()
      || (NodeUtil.isAssignmentOp(parent)
      && parent.getFirstChild() == n));
}
 

private boolean isLValue(Node n) {
  Node parent = n.getParent();
  return (parent.isInc()
      || parent.isDec()
      || (NodeUtil.isAssignmentOp(parent)
      && parent.getFirstChild() == n));
}
 

/**
 * Determines whether the given property with @const tag got reassigned
 * @param t The current traversal.
 * @param getprop The getprop node.
 */
private void checkConstantProperty(NodeTraversal t,
    Node getprop) {
  // Check whether the property is modified
  Node parent = getprop.getParent();
  boolean isDelete = parent.isDelProp();
  if (!(NodeUtil.isAssignmentOp(parent) && parent.getFirstChild() == getprop)
      && !parent.isInc() && !parent.isDec()
      && !isDelete) {
    return;
  }

  ObjectType objectType =
    ObjectType.cast(dereference(getprop.getFirstChild().getJSType()));
  String propertyName = getprop.getLastChild().getString();

  boolean isConstant = isPropertyDeclaredConstant(objectType, propertyName);

  // Check whether constant properties are reassigned
  if (isConstant) {
    if (isDelete) {
      compiler.report(
          t.makeError(getprop, CONST_PROPERTY_DELETED, propertyName));
      return;
    }

    ObjectType oType = objectType;
    while (oType != null) {
      if (oType.hasReferenceName()) {
        if (initializedConstantProperties.containsEntry(
                oType.getReferenceName(), propertyName)) {
          compiler.report(
              t.makeError(getprop, CONST_PROPERTY_REASSIGNED_VALUE,
                  propertyName));
          break;
        }
      }
      oType = oType.getImplicitPrototype();
    }

    Preconditions.checkState(objectType.hasReferenceName());
    initializedConstantProperties.put(objectType.getReferenceName(),
        propertyName);

    // Add the prototype when we're looking at an instance object
    if (objectType.isInstanceType()) {
      ObjectType prototype = objectType.getImplicitPrototype();
      if (prototype != null) {
        if (prototype.hasProperty(propertyName)
            && prototype.hasReferenceName()) {
          initializedConstantProperties.put(prototype.getReferenceName(),
              propertyName);
        }
      }
    }
  }
}