Java Node.getDouble方法代码示例

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Gets the boolean value of a node that represents a literal. This method
 * effectively emulates the <code>Boolean()</code> JavaScript cast function.
 *
 * @throws IllegalArgumentException If {@code n} is not a literal value
 */
static boolean getBooleanValue(Node n) {
  switch (n.getType()) {
    case Token.STRING:
      return n.getString().length() > 0;

    case Token.NUMBER:
      return n.getDouble() != 0;

    case Token.NULL:
    case Token.FALSE:
    case Token.VOID:
      return false;

    case Token.NAME:
      String name = n.getString();
      if ("undefined".equals(name)
          || "NaN".equals(name)) {
        // We assume here that programs don't change the value of the keyword
        // undefined to something other than the value undefined.
        return false;
      } else if ("Infinity".equals(name)) {
        return true;
      }
      break;

    case Token.TRUE:
    case Token.ARRAYLIT:
    case Token.OBJECTLIT:
    case Token.REGEXP:
      return true;
  }
  throw new IllegalArgumentException("Non-literal value: " + n);
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Gets the value of a node as a String, or null if it cannot be converted.
 * When it returns a non-null String, this method effectively emulates the
 * <code>String()</code> JavaScript cast function.
 */
static String getStringValue(Node n) {
  // TODO(user): Convert constant array, object, and regex literals as well.
  switch (n.getType()) {
    case Token.NAME:
    case Token.STRING:
      return n.getString();

    case Token.NUMBER:
      double value = n.getDouble();
      long longValue = (long) value;

      // Return "1" instead of "1.0"
      if (longValue == value) {
        return Long.toString(longValue);
      } else {
        return Double.toString(n.getDouble());
      }

    case Token.FALSE:
    case Token.TRUE:
    case Token.NULL:
      return Node.tokenToName(n.getType());

    case Token.VOID:
      return "undefined";
  }
  return null;
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Try to fold arithmetic binary operators
 */
void tryFoldArithmetic(NodeTraversal t, Node n, Node left, Node right,
                       Node parent) {

  if (left.getType() == Token.NUMBER &&
      right.getType() == Token.NUMBER) {
    double result;
    double lval = left.getDouble();
    double rval = right.getDouble();

    switch (n.getType()) {
      case Token.ADD:
        result = lval + rval;
        break;
      case Token.SUB:
        result = lval - rval;
        break;
      case Token.MUL:
        result = lval * rval;
        break;
      case Token.DIV:
        if (rval == 0) {
          error(t, DIVIDE_BY_0_ERROR, right);
          return;
        }
        result = lval / rval;
        break;
      default:
        throw new Error("Unknown arithmetic operator");
    }

    // length of the left and right value plus 1 byte for the operator.
    if (String.valueOf(result).length() <=
        String.valueOf(lval).length() + String.valueOf(rval).length() + 1) {
      parent.replaceChild(n, Node.newNumber(result));
      t.getCompiler().reportCodeChange();
    }
 }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Try to fold arithmetic binary operators
 */
void tryFoldBitAndOr(NodeTraversal t, Node n, Node left, Node right,
                     Node parent) {

  if (left.getType() == Token.NUMBER &&
      right.getType() == Token.NUMBER) {
    double result;
    double lval = left.getDouble();
    double rval = right.getDouble();

    // For now, we are being extra conservative, and only folding ints in
    // the range MIN_VALUE-MAX_VALUE
    if (lval < Integer.MIN_VALUE || lval > Integer.MAX_VALUE ||
        rval < Integer.MIN_VALUE || rval > Integer.MAX_VALUE) {

      // Fall back through and let the javascript use the larger values
      return;
    }

    // Convert the numbers to ints
    int lvalInt = (int) lval;
    if (lvalInt != lval) {
      return;
    }

    int rvalInt = (int) rval;
    if (rvalInt != rval) {
      return;
    }

    switch (n.getType()) {
      case Token.BITAND:
        result = lvalInt & rvalInt;
        break;
      case Token.BITOR:
        result = lvalInt | rvalInt;
        break;
      default:
        throw new Error("Unknown bitwise operator");
    }
    parent.replaceChild(n, Node.newNumber(result));
    t.getCompiler().reportCodeChange();
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Try to fold shift operations
 */
void tryFoldShift(NodeTraversal t, Node n, Node left, Node right,
                  Node parent) {

  if (left.getType() == Token.NUMBER &&
      right.getType() == Token.NUMBER) {

    double result;
    double lval = left.getDouble();
    double rval = right.getDouble();

    // check ranges.  We do not do anything that would clip the double to
    // a 32-bit range, since the user likely does not intend that.
    if (!(lval >= Integer.MIN_VALUE && lval <= Integer.MAX_VALUE)) {
      error(t, BITWISE_OPERAND_OUT_OF_RANGE, left);
      return;
    }

    // only the lower 5 bits are used when shifting, so don't do anything
    // if the shift amount is outside [0,32)
    if (!(rval >= 0 && rval < 32)) {
      error(t, SHIFT_AMOUNT_OUT_OF_BOUNDS, right);
      return;
    }

    // Convert the numbers to ints
    int lvalInt = (int) lval;
    if (lvalInt != lval) {
      error(t, FRACTIONAL_BITWISE_OPERAND, left);
      return;
    }

    int rvalInt = (int) rval;
    if (rvalInt != rval) {
      error(t, FRACTIONAL_BITWISE_OPERAND, right);
      return;
    }

    switch (n.getType()) {
      case Token.LSH:
        result = lvalInt << rvalInt;
        break;
      case Token.RSH:
        result = lvalInt >> rvalInt;
        break;
      case Token.URSH:
        result = lvalInt >>> rvalInt;
        break;
      default:
        throw new AssertionError("Unknown shift operator: " +
            Node.tokenToName(n.getType()));
    }
    parent.replaceChild(n, Node.newNumber(result));
    t.getCompiler().reportCodeChange();
  }
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Try to evaluate String.indexOf/lastIndexOf:
 *     "abcdef".indexOf("bc") -> 1
 *     "abcdefbc".indexOf("bc", 3) -> 6
 */
void tryFoldStringIndexOf(NodeTraversal t, Node n, Node left, Node right,
                          Node parent) {
  if (!NodeUtil.isGetProp(left) || !NodeUtil.isImmutableValue(right)) {
    return;
  }

  Node lstringNode = left.getFirstChild();
  Node functionName = lstringNode.getNext();

  if ((lstringNode.getType() != Token.STRING) ||
      (!functionName.getString().equals("indexOf") &&
      !functionName.getString().equals("lastIndexOf"))) {
    return;
  }

  String lstring = NodeUtil.getStringValue(lstringNode);
  boolean isIndexOf = functionName.getString().equals("indexOf");
  Node firstArg = right;
  Node secondArg = right.getNext();
  String searchValue = NodeUtil.getStringValue(firstArg);
  // searchValue must be a valid string.
  if (searchValue == null) {
    return;
  }
  int fromIndex = isIndexOf ? 0 : lstring.length();
  if (secondArg != null) {
    // Third-argument and non-numeric second arg are problematic. Discard.
    if ((secondArg.getNext() != null) ||
        (secondArg.getType() != Token.NUMBER)) {
      return;
    } else {
      fromIndex = (int) secondArg.getDouble();
    }
  }
  int indexVal = isIndexOf ? lstring.indexOf(searchValue, fromIndex)
                           : lstring.lastIndexOf(searchValue, fromIndex);
  Node newNode = Node.newNumber(indexVal);
  parent.replaceChild(n, newNode);

  t.getCompiler().reportCodeChange();
}
 

import com.google.javascript.rhino.Node; //导入方法依赖的package包/类
/**
 * Try to fold array-element. e.g [1, 2, 3][10];
 */
void tryFoldGetElem(NodeTraversal t, Node n, Node left, Node right,
                    Node parent) {
  if (left.getType() == Token.ARRAYLIT) {

    if (right.getType() != Token.NUMBER) {
      // Sometimes people like to use complex expressions to index into
      // arrays, or strings to index into array methods.
      return;
    }

    double index = right.getDouble();
    int intIndex = (int) index;
    if (intIndex != index) {
      t.getCompiler().report(JSError.make(t, right,
          INVALID_GETELEM_INDEX_ERROR, String.valueOf(index)));
      return;
    }

    if (intIndex < 0) {
      t.getCompiler().report(JSError.make(t, n, INDEX_OUT_OF_BOUNDS_ERROR,
          String.valueOf(intIndex)));
      return;
    }

    Node elem = left.getFirstChild();
    for (int i = 0; elem != null && i < intIndex; i++) {
      elem = elem.getNext();
    }

    if (elem == null) {
      t.getCompiler().report(JSError.make(t, n, INDEX_OUT_OF_BOUNDS_ERROR,
          String.valueOf(intIndex)));
      return;
    }

    // Replace the entire GETELEM with the value
    left.removeChild(elem);
    parent.replaceChild(n, elem);
    t.getCompiler().reportCodeChange();
  }
}