Java TernaryValue.toBoolean方法代码示例

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
@Override
public boolean apply(EdgeTuple<Node, Branch> input) {
  Branch branch = input.edge;
  if (!branch.isConditional()) {
    return true;
  }
  Node predecessor = input.sourceNode;
  Node condition = NodeUtil.getConditionExpression(predecessor);

  // TODO(user): Handle more complicated expression like true == true,
  // etc....
  if (condition != null) {
    TernaryValue val = NodeUtil.getBooleanValue(condition);
    if (val != TernaryValue.UNKNOWN) {
      return val.toBoolean(true) == (branch == Branch.ON_TRUE);
    }
  }
  return true;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
public boolean apply(DiGraphEdge<Node, ControlFlowGraph.Branch> input) {
  // First skill all exceptions.
  Branch branch = input.getValue();
  if (branch == Branch.ON_EX) {
    return false;
  } else if (branch.isConditional()) {
    Node condition = NodeUtil.getConditionExpression(
        input.getSource().getValue());
    // TODO(user): We CAN make this bit smarter just looking at
    // constants. We DO have a full blown ReverseAbstractInterupter and
    // type system that can evaluate some impressions' boolean value but
    // for now we will keep this pass lightweight.
    if (condition != null) {
      TernaryValue val = NodeUtil.getBooleanValue(condition);
      if (val != TernaryValue.UNKNOWN) {
        return val.toBoolean(true) == (Branch.ON_TRUE == branch);
      }
    }
  }
  return true;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
@Override
public boolean apply(EdgeTuple<Node, Branch> input) {
  Branch branch = input.edge;
  if (!branch.isConditional()) {
    return true;
  }
  Node predecessor = input.sourceNode;
  Node condition = NodeUtil.getConditionExpression(predecessor);

  // TODO(user): Handle more complicated expression like true == true,
  // etc....
  if (condition != null) {
    TernaryValue val = NodeUtil.getImpureBooleanValue(condition);
    if (val != TernaryValue.UNKNOWN) {
      return val.toBoolean(true) == (branch == Branch.ON_TRUE);
    }
  }
  return true;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
@Override
public boolean apply(DiGraphEdge<Node, ControlFlowGraph.Branch> input) {
  // First skill all exceptions.
  Branch branch = input.getValue();
  if (branch == Branch.ON_EX) {
    return false;
  } else if (branch.isConditional()) {
    Node condition = NodeUtil.getConditionExpression(
        input.getSource().getValue());
    // TODO(user): We CAN make this bit smarter just looking at
    // constants. We DO have a full blown ReverseAbstractInterupter and
    // type system that can evaluate some impressions' boolean value but
    // for now we will keep this pass lightweight.
    if (condition != null) {
      TernaryValue val = NodeUtil.getImpureBooleanValue(condition);
      if (val != TernaryValue.UNKNOWN) {
        return val.toBoolean(true) == (Branch.ON_TRUE == branch);
      }
    }
  }
  return true;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try folding HOOK (?:) if the condition results of the condition is known.
 * @return the replacement node, if changed, or the original if not
 */
private Node tryFoldHook(Node n) {
  Preconditions.checkState(n.getType() == Token.HOOK);
  Node parent = n.getParent();
  Preconditions.checkNotNull(parent);
  Node cond = n.getFirstChild();
  Node thenBody = cond.getNext();
  Node elseBody = thenBody.getNext();

  TernaryValue condValue = NodeUtil.getExpressionBooleanValue(cond);
  if (condValue == TernaryValue.UNKNOWN) {
    return n;  // We can't remove branches otherwise!
  }

  // Transform "(a = 2) ? x =2 : y" into "a=2,x=2"
  n.detachChildren();
  Node branchToKeep = condValue.toBoolean(true) ? thenBody : elseBody;
  Node replacement;
  if (mayHaveSideEffects(cond)) {
    replacement = new Node(Token.COMMA).copyInformationFrom(n);
    replacement.addChildToFront(cond);
    replacement.addChildToBack(branchToKeep);
  } else {
    replacement = branchToKeep;
  }

  parent.replaceChild(n, replacement);
  reportCodeChange();
  return replacement;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try folding HOOK (?:) if the condition results of the condition is known.
 * @return the replacement node, if changed, or the original if not
 */
private Node tryFoldHook(Node n) {
  Preconditions.checkState(n.isHook());
  Node parent = n.getParent();
  Preconditions.checkNotNull(parent);
  Node cond = n.getFirstChild();
  Node thenBody = cond.getNext();
  Node elseBody = thenBody.getNext();

  TernaryValue condValue = NodeUtil.getImpureBooleanValue(cond);
  if (condValue == TernaryValue.UNKNOWN) {
    // If the result nodes are equivalent, then one of the nodes can be
    // removed and it doesn't matter which.
    if (!areNodesEqualForInlining(thenBody, elseBody)) {
      return n;  // We can't remove branches otherwise!
    }
  }

  // Transform "(a = 2) ? x =2 : y" into "a=2,x=2"
  n.detachChildren();
  Node branchToKeep = condValue.toBoolean(true) ? thenBody : elseBody;
  Node replacement;
  if (mayHaveSideEffects(cond)) {
    replacement = IR.comma(cond, branchToKeep).srcref(n);
  } else {
    replacement = branchToKeep;
  }

  parent.replaceChild(n, replacement);
  reportCodeChange();
  return replacement;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try to fold a AND/OR node.
 */
private Node tryFoldAndOr(Node n, Node left, Node right) {
  Node parent = n.getParent();

  Node result = null;

  int type = n.getType();

  TernaryValue leftVal = NodeUtil.getImpureBooleanValue(left);

  if (leftVal != TernaryValue.UNKNOWN) {
    boolean lval = leftVal.toBoolean(true);

    // (TRUE || x) => TRUE (also, (3 || x) => 3)
    // (FALSE && x) => FALSE
    if (lval && type == Token.OR ||
        !lval && type == Token.AND) {
      result = left;

    } else if (!mayHaveSideEffects(left)) {
      // (FALSE || x) => x
      // (TRUE && x) => x
      result = right;
    }
  }

  // Note: Right hand side folding is handled by
  // PeepholeSubstituteAlternateSyntax#tryMinimizeCondition

  if (result != null) {
    // Fold it!
    n.removeChild(result);
    parent.replaceChild(n, result);
    reportCodeChange();

    return result;
  } else {
    return n;
  }
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try folding HOOK (?:) if the condition results of the condition is known.
 * @return the replacement node, if changed, or the original if not
 */
private Node tryFoldHook(Node n) {
  Preconditions.checkState(n.isHook());
  Node parent = n.getParent();
  Preconditions.checkNotNull(parent);
  Node cond = n.getFirstChild();
  Node thenBody = cond.getNext();
  Node elseBody = thenBody.getNext();

  TernaryValue condValue = NodeUtil.getImpureBooleanValue(cond);
  if (condValue == TernaryValue.UNKNOWN) {
    // If the result nodes are equivalent, then one of the nodes can be
    // removed and it doesn't matter which.
    if (!areNodesEqualForInlining(thenBody, elseBody)) {
      return n;  // We can't remove branches otherwise!
    }
  }

  // Transform "(a = 2) ? x =2 : y" into "a=2,x=2"
  Node branchToKeep = condValue.toBoolean(true) ? thenBody : elseBody;
  Node replacement;
  boolean condHasSideEffects = mayHaveSideEffects(cond);
  // Must detach after checking for side effects, to ensure that the parents
  // of nodes are set correctly.
  n.detachChildren();

  if (condHasSideEffects) {
    replacement = IR.comma(cond, branchToKeep).srcref(n);
  } else {
    replacement = branchToKeep;
  }

  parent.replaceChild(n, replacement);
  reportCodeChange();
  return replacement;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try to fold a AND/OR node.
 */
private Node tryFoldAndOr(Node n, Node left, Node right) {
  Node parent = n.getParent();

  Node result = null;

  int type = n.getType();

  TernaryValue leftVal = NodeUtil.getImpureBooleanValue(left);

  if (leftVal != TernaryValue.UNKNOWN) {
    boolean lval = leftVal.toBoolean(true);

    // (TRUE || x) => TRUE (also, (3 || x) => 3)
    // (FALSE && x) => FALSE
    if (lval && type == Token.OR ||
        !lval && type == Token.AND) {
      result = left;

    } else if (!mayHaveSideEffects(left)) {
      // (FALSE || x) => x
      // (TRUE && x) => x
      result = right;
    }
  }

  // Note: Right hand side folding is handled by
  // PeepholeMinimizeConditions#tryMinimizeCondition

  if (result != null) {
    // Fold it!
    n.removeChild(result);
    parent.replaceChild(n, result);
    reportCodeChange();

    return result;
  } else {
    return n;
  }
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Attempt to replace the condition of if or hook immediately that is a
 * reference to a name that is assigned immediately before.
 */
private void tryOptimizeConditionalAfterAssign(Node n) {
  Node next = n.getNext();

  // Look for patterns like the following and replace the if-condition with
  // a constant value so it can later be folded:
  //   var a = /a/;
  //   if (a) {foo(a)}
  // or
  //   a = 0;
  //   a ? foo(a) : c;
  // or
  //   a = 0;
  //   a || foo(a);
  // or
  //   a = 0;
  //   a && foo(a)
  //
  // TODO(johnlenz): This would be better handled by control-flow sensitive
  // constant propagation. As the other case that I want to handle is:
  //   i=0; for(;i<0;i++){}
  // as right now nothing facilitates removing a loop like that.
  // This is here simply to remove the cruft left behind goog.userAgent and
  // similar cases.

  if (isSimpleAssignment(n) && isConditionalStatement(next)) {
    Node lhsAssign = getSimpleAssignmentName(n);

    Node condition = getConditionalStatementCondition(next);
    if (NodeUtil.isName(lhsAssign) && NodeUtil.isName(condition)
        && lhsAssign.getString().equals(condition.getString())) {
      Node rhsAssign = getSimpleAssignmentValue(n);
      TernaryValue value = NodeUtil.getExpressionBooleanValue(rhsAssign);
      if (value != TernaryValue.UNKNOWN) {
        int replacementConditionNodeType =
          (value.toBoolean(true)) ? Token.TRUE : Token.FALSE;
        condition.getParent().replaceChild(condition,
            new Node(replacementConditionNodeType));
        reportCodeChange();
      }
    }
  }
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try to fold a AND/OR node.
 */
private Node tryFoldAndOr(Node n, Node left, Node right) {
  Node parent = n.getParent();

  Node result = null;

  int type = n.getType();

  TernaryValue leftVal = NodeUtil.getBooleanValue(left);

  if (leftVal != TernaryValue.UNKNOWN) {
    boolean lval = leftVal.toBoolean(true);

    // (TRUE || x) => TRUE (also, (3 || x) => 3)
    // (FALSE && x) => FALSE
    if (lval && type == Token.OR ||
        !lval && type == Token.AND) {
      result = left;

    } else {
      // (FALSE || x) => x
      // (TRUE && x) => x
      result = right;
    }
  } else {
    TernaryValue rightVal = NodeUtil.getBooleanValue(right);
    if (rightVal != TernaryValue.UNKNOWN) {

    // Note: We cannot always fold when the constant is on the
    // right, because the typed value of the expression will depend
    // on the type of the constant on the right, even if the boolean
    // equivalent of the value does not. Specifically, in "a = x ||
    // 0", a will be numeric 0 if x is undefined (and hence is
    // e.g. a valid array index). However, it is safe to fold
    // e.g. "if (x || true)" because 'if' doesn't care if the
    // expression is 'true' or '3'.
    int pt = parent.getType();
    if (pt == Token.IF || pt == Token.WHILE || pt == Token.DO ||
        (pt == Token.FOR && NodeUtil.getConditionExpression(parent) == n) ||
        (pt == Token.HOOK && parent.getFirstChild() == n)) {
      boolean rval = rightVal.toBoolean(true);

      // (x || FALSE) => x
      // (x && TRUE) => x
      if (type == Token.OR && !rval ||
          type == Token.AND && rval) {
        result = left;
      } else {
        // If x has no side-effects:
        //   (x || TRUE) => TRUE
        //   (x && FALSE) => FALSE
        if (!mayHaveSideEffects(left)) {
          result = right;
        }
      }
      }
    }
  }

  // Note: The parser parses 'x && FALSE && y' as 'x && (FALSE && y)', so
  // there is not much need to worry about const values on left's
  // right child.

  if (result != null) {
    // Fold it!
    n.removeChild(result);
    parent.replaceChild(n, result);
    reportCodeChange();

    return result;
  } else {
    return n;
  }
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //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): regex literals as well.
  switch (n.getType()) {
    case Token.STRING:
    case Token.STRING_KEY:
      return n.getString();

    case Token.NAME:
      String name = n.getString();
      if ("undefined".equals(name)
          || "Infinity".equals(name)
          || "NaN".equals(name)) {
        return name;
      }
      break;

    case Token.NUMBER:
      return getStringValue(n.getDouble());

    case Token.FALSE:
      return "false";

    case Token.TRUE:
      return "true";

    case Token.NULL:
      return "null";

    case Token.VOID:
      return "undefined";

    case Token.NOT:
      TernaryValue child = getPureBooleanValue(n.getFirstChild());
      if (child != TernaryValue.UNKNOWN) {
        return child.toBoolean(true) ? "false" : "true"; // reversed.
      }
      break;

    case Token.ARRAYLIT:
      return arrayToString(n);

    case Token.OBJECTLIT:
      return "[object Object]";
  }
  return null;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Gets the value of a node as a Number, or null if it cannot be converted.
 * When it returns a non-null Double, this method effectively emulates the
 * <code>Number()</code> JavaScript cast function.
 */
static Double getNumberValue(Node n) {
  switch (n.getType()) {
    case Token.TRUE:
      return 1.0;

    case Token.FALSE:
    case Token.NULL:
      return 0.0;

    case Token.NUMBER:
      return n.getDouble();

    case Token.VOID:
      if (mayHaveSideEffects(n.getFirstChild())) {
        return null;
      } else {
        return Double.NaN;
      }

    case Token.NAME:
      // Check for known constants
      String name = n.getString();
      if (name.equals("undefined")) {
        return Double.NaN;
      }
      if (name.equals("NaN")) {
        return Double.NaN;
      }
      if (name.equals("Infinity")) {
        return Double.POSITIVE_INFINITY;
      }
      return null;

    case Token.NEG:
      if (n.getChildCount() == 1 && n.getFirstChild().isName()
          && n.getFirstChild().getString().equals("Infinity")) {
        return Double.NEGATIVE_INFINITY;
      }
      return null;

    case Token.NOT:
      TernaryValue child = getPureBooleanValue(n.getFirstChild());
      if (child != TernaryValue.UNKNOWN) {
        return child.toBoolean(true) ? 0.0 : 1.0; // reversed.
      }
      break;

    case Token.STRING:
      return getStringNumberValue(n.getString());

    case Token.ARRAYLIT:
    case Token.OBJECTLIT:
      String value = getStringValue(n);
      return value != null ? getStringNumberValue(value) : null;
  }

  return null;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Gets the value of a node as a Number, or null if it cannot be converted.
 * When it returns a non-null Double, this method effectively emulates the
 * <code>Number()</code> JavaScript cast function.
 *
 * @param n The node.
 * @return The value of a node as a Number, or null if it cannot be converted.
 */
static Double getNumberValue(Node n) {
  switch (n.getToken()) {
    case TRUE:
      return 1.0;

    case FALSE:
    case NULL:
      return 0.0;

    case NUMBER:
      return n.getDouble();

    case VOID:
      if (mayHaveSideEffects(n.getFirstChild())) {
        return null;
      } else {
        return Double.NaN;
      }

    case NAME:
      // Check for known constants
      String name = n.getString();
      if (name.equals("undefined")) {
        return Double.NaN;
      }
      if (name.equals("NaN")) {
        return Double.NaN;
      }
      if (name.equals("Infinity")) {
        return Double.POSITIVE_INFINITY;
      }
      return null;

    case NEG:
      if (n.hasOneChild() && n.getFirstChild().isName()
          && n.getFirstChild().getString().equals("Infinity")) {
        return Double.NEGATIVE_INFINITY;
      }
      return null;

    case NOT:
      TernaryValue child = getPureBooleanValue(n.getFirstChild());
      if (child != TernaryValue.UNKNOWN) {
        return child.toBoolean(true) ? 0.0 : 1.0; // reversed.
      }
      break;

    case TEMPLATELIT:
      String string = getStringValue(n);
      if (string == null) {
        return null;
      }
      return getStringNumberValue(string);

    case STRING:
      return getStringNumberValue(n.getString());

    case ARRAYLIT:
    case OBJECTLIT:
      String value = getStringValue(n);
      return value != null ? getStringNumberValue(value) : null;
    default:
      break;
  }

  return null;
}
 

import com.google.javascript.rhino.jstype.TernaryValue; //导入方法依赖的package包/类
/**
 * Try folding HOOK (?:) if the condition results of the condition is known.
 * @return the replacement node, if changed, or the original if not
 */
private Node tryFoldHook(Node n) {
  checkState(n.isHook(), n);
  Node parent = n.getParent();
  checkNotNull(parent);
  Node cond = n.getFirstChild();
  Node thenBody = cond.getNext();
  Node elseBody = thenBody.getNext();

  TernaryValue condValue = NodeUtil.getImpureBooleanValue(cond);
  if (condValue == TernaryValue.UNKNOWN) {
    // If the result nodes are equivalent, then one of the nodes can be
    // removed and it doesn't matter which.
    if (!areNodesEqualForInlining(thenBody, elseBody)) {
      return n;  // We can't remove branches otherwise!
    }
  }

  // Transform "(a = 2) ? x =2 : y" into "a=2,x=2"
  Node branchToKeep;
  Node branchToRemove;
  if (condValue.toBoolean(true)) {
    branchToKeep = thenBody;
    branchToRemove = elseBody;
  } else {
    branchToKeep = elseBody;
    branchToRemove = thenBody;
  }

  Node replacement;
  boolean condHasSideEffects = mayHaveSideEffects(cond);
  // Must detach after checking for side effects, to ensure that the parents
  // of nodes are set correctly.
  n.detachChildren();
  if (condHasSideEffects) {
    replacement = IR.comma(cond, branchToKeep).srcref(n);
  } else {
    replacement = branchToKeep;
    NodeUtil.markFunctionsDeleted(cond, compiler);
  }

  parent.replaceChild(n, replacement);
  compiler.reportChangeToEnclosingScope(replacement);
  NodeUtil.markFunctionsDeleted(branchToRemove, compiler);
  return replacement;
}