public void Visit(JsConstantWrapper node)
{
if (node != null)
{
// allow string, number, true, false, and null.
switch (node.PrimitiveType)
{
case JsPrimitiveType.Boolean:
m_writer.Write((bool)node.Value ? "true" : "false");
break;
case JsPrimitiveType.Null:
m_writer.Write("null");
break;
case JsPrimitiveType.Number:
OutputNumber((double)node.Value, node.Context);
break;
case JsPrimitiveType.String:
case JsPrimitiveType.Other:
// string -- or treat it like a string
OutputString(node.Value.ToString());
break;
}
}
}
public override void Visit(JsConstantWrapper node)
{
if (node != null)
{
// measure
if (node.PrimitiveType == JsPrimitiveType.Boolean)
{
if (m_measure)
{
// if we are converting true/false literals to !0/!1, then
// a logical-not doesn't add or subtract anything. But if we aren't,
// we need to add/subtract the difference in the length between the
// "true" and "false" strings
if (!m_parser.Settings.MinifyCode ||
!m_parser.Settings.IsModificationAllowed(JsTreeModifications.BooleanLiteralsToNotOperators))
{
// converting true to false adds a character, false to true subtracts
m_delta += node.ToBoolean() ? 1 : -1;
}
}
else
{
// convert - just flip the boolean value
node.Value = !node.ToBoolean();
}
}
else
{
// just the same typical operation as most other nodes for other types
TypicalHandler(node);
}
}
}
public void Visit(JsConstantWrapper node)
{
if (node != null)
{
node.Index = NextOrderIndex;
}
}
private static bool IsMinificationHint(JsConstantWrapper node)
{
var isHint = false;
if (node.PrimitiveType == JsPrimitiveType.String)
{
// try splitting on commas and removing empty items
var sections = node.ToString().Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
foreach (var section in sections)
{
// valid hints are:
// name:nomunge don't automatically rename the field defined in this scope named "name"
// if name is missing (colon is the first character) or "*", then don't rename ANY
// fields defined in the current scope.
var ndxColon = section.IndexOf(':');
if (ndxColon >= 0)
{
// make sure this is a "nomunge" hint. If it is, then the entire node is treated as a hint and
// will be removed from the AST.
if (string.Compare(section.Substring(ndxColon + 1).Trim(), "nomunge", StringComparison.OrdinalIgnoreCase) == 0)
{
// it is.
isHint = true;
// get the name that we don't want to munge. Null means all. Convert "*"
// to null.
var identifier = section.Substring(0, ndxColon).Trim();
if (string.IsNullOrEmpty(identifier) || string.CompareOrdinal(identifier, "*") == 0)
{
identifier = null;
}
// get the current scope and iterate over all the fields within it
// looking for just the ones that are defined here (outer is null)
var currentScope = node.EnclosingScope;
foreach (var field in currentScope.NameTable.Values)
{
if (field.OuterField == null)
{
// if the identifier is null or matches exactly, mark it as not crunchable
if (identifier == null || string.CompareOrdinal(identifier, field.Name) == 0)
{
field.CanCrunch = false;
}
}
}
}
}
}
}
return(isHint);
}
public bool IsSingleConstantArgument(string argumentValue)
{
if (m_list.Count == 1)
{
JsConstantWrapper constantWrapper = m_list[0] as JsConstantWrapper;
if (constantWrapper != null &&
string.CompareOrdinal(constantWrapper.Value.ToString(), argumentValue) == 0)
{
return(true);
}
}
return(false);
}
public override void Visit(JsConstantWrapper node)
{
if (node != null)
{
// no children, so don't bother calling the base.
if (node.PrimitiveType == JsPrimitiveType.Boolean
&& m_parser.Settings.IsModificationAllowed(JsTreeModifications.BooleanLiteralsToNotOperators))
{
node.Parent.ReplaceChild(node, new JsUnaryOperator(node.Context, m_parser)
{
Operand = new JsConstantWrapper(node.ToBoolean() ? 0 : 1, JsPrimitiveType.Number, node.Context, m_parser),
OperatorToken = JsToken.LogicalNot
});
}
}
}
public override void Visit(JsConstantWrapper node)
{
if (node != null)
{
// no children, so don't bother calling the base.
if (node.PrimitiveType == JsPrimitiveType.Boolean &&
m_parser.Settings.IsModificationAllowed(JsTreeModifications.BooleanLiteralsToNotOperators))
{
node.Parent.ReplaceChild(node, new JsUnaryOperator(node.Context, m_parser)
{
Operand = new JsConstantWrapper(node.ToBoolean() ? 0 : 1, JsPrimitiveType.Number, node.Context, m_parser),
OperatorToken = JsToken.LogicalNot
});
}
}
}
public override void Visit(JsConstantWrapper node)
{
// by default this node has nothing to do and no children to recurse.
// but if this node's parent is a block, then this is an expression statement
// consisting of a single string literal. Normally we would ignore these -- if
// they occured at the top of the block they would be DirectivePrologues. So because
// this exists, it must not be at the top. But we still want to check it for the nomunge
// hints and respect them if that's what it is.
if (node != null && node.Parent is JsBlock)
{
// if this is a hint, process it as such.
if (IsMinificationHint(node))
{
// and then remove it. We can do that here, because blocks are processed
// in reverse order.
node.Parent.ReplaceChild(node, null);
}
}
}
private JsConstantWrapper LessThanOrEqual(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
if (left.IsStringLiteral && right.IsStringLiteral)
{
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
// do a straight ordinal comparison of the strings
newLiteral = new JsConstantWrapper(string.CompareOrdinal(left.ToString(), right.ToString()) <= 0, JsPrimitiveType.Boolean, null, m_parser);
}
}
else
{
try
{
// either one or both are NOT a string -- numeric comparison
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new JsConstantWrapper(left.ToNumber() <= right.ToNumber(), JsPrimitiveType.Boolean, null, m_parser);
}
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
}
}
return newLiteral;
}
private void EvalToTheLeft(JsBinaryOperator node, JsConstantWrapper thisConstant, JsConstantWrapper otherConstant, JsBinaryOperator leftOperator)
{
if (leftOperator.OperatorToken == JsToken.Plus && node.OperatorToken == JsToken.Plus)
{
// plus-plus
// the other operation goes first, so if the other constant is a string, then we know that
// operation will do a string concatenation, which will force our operation to be a string
// concatenation. If the other constant is not a string, then we won't know until runtime and
// we can't combine them.
if (otherConstant.IsStringLiteral)
{
// the other constant is a string -- so we can do the string concat and combine them
JsConstantWrapper newLiteral = StringConcat(otherConstant, thisConstant);
if (newLiteral != null)
{
RotateFromLeft(node, leftOperator, newLiteral);
}
}
}
else if (leftOperator.OperatorToken == JsToken.Minus)
{
if (node.OperatorToken == JsToken.Plus)
{
// minus-plus
// the minus operator goes first and will always convert to number.
// if our constant is not a string, then it will be a numeric addition and we can combine them.
// if our constant is a string, then we'll end up doing a string concat, so we can't combine
if (!thisConstant.IsStringLiteral)
{
// two numeric operators. a-n1+n2 is the same as a-(n1-n2)
JsConstantWrapper newLiteral = Minus(otherConstant, thisConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
// a-(-n) is numerically equivalent as a+n -- and takes fewer characters to represent.
// BUT we can't do that because that might change a numeric operation (the original minus)
// to a string concatenation if the unknown operand turns out to be a string!
RotateFromLeft(node, leftOperator, newLiteral);
}
else
{
// if the left-left is a constant, then we can try combining with it
JsConstantWrapper leftLeft = leftOperator.Operand1 as JsConstantWrapper;
if (leftLeft != null)
{
EvalFarToTheLeft(node, thisConstant, leftLeft, leftOperator);
}
}
}
}
else if (node.OperatorToken == JsToken.Minus)
{
// minus-minus. Both operations are numeric.
// (a-n1)-n2 => a-(n1+n2), so we can add the two constants and subtract from
// the left-hand non-constant.
JsConstantWrapper newLiteral = NumericAddition(otherConstant, thisConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
// make it the new right-hand literal for the left-hand operator
// and make the left-hand operator replace our operator
RotateFromLeft(node, leftOperator, newLiteral);
}
else
{
// if the left-left is a constant, then we can try combining with it
JsConstantWrapper leftLeft = leftOperator.Operand1 as JsConstantWrapper;
if (leftLeft != null)
{
EvalFarToTheLeft(node, thisConstant, leftLeft, leftOperator);
}
}
}
}
else if (leftOperator.OperatorToken == node.OperatorToken
&& (node.OperatorToken == JsToken.Multiply || node.OperatorToken == JsToken.Divide))
{
// either multiply-multiply or divide-divide
// either way, we use the other operand and the product of the two constants.
// if the product blows up to an infinte value, then don't combine them because that
// could change the way the program goes at runtime, depending on the unknown value.
JsConstantWrapper newLiteral = Multiply(otherConstant, thisConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, newLiteral))
{
RotateFromLeft(node, leftOperator, newLiteral);
}
}
else if ((leftOperator.OperatorToken == JsToken.Multiply && node.OperatorToken == JsToken.Divide)
|| (leftOperator.OperatorToken == JsToken.Divide && node.OperatorToken == JsToken.Multiply))
{
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
// get the two division operators
JsConstantWrapper otherOverThis = Divide(otherConstant, thisConstant);
JsConstantWrapper thisOverOther = Divide(thisConstant, otherConstant);
// get the lengths
int otherOverThisLength = otherOverThis != null ? otherOverThis.ToCode().Length : int.MaxValue;
int thisOverOtherLength = thisOverOther != null ? thisOverOther.ToCode().Length : int.MaxValue;
// we'll want to use whichever one is shorter, and whichever one does NOT involve an overflow
// or possible underflow
if (otherOverThis != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, otherOverThis)
&& (thisOverOther == null || otherOverThisLength < thisOverOtherLength))
{
// but only if it's smaller than the original expression
if (otherOverThisLength <= otherConstant.ToCode().Length + thisConstant.ToCode().Length + 1)
{
// same operator
RotateFromLeft(node, leftOperator, otherOverThis);
}
}
else if (thisOverOther != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, thisOverOther))
{
// but only if it's smaller than the original expression
if (thisOverOtherLength <= otherConstant.ToCode().Length + thisConstant.ToCode().Length + 1)
{
// opposite operator
leftOperator.OperatorToken = leftOperator.OperatorToken == JsToken.Multiply ? JsToken.Divide : JsToken.Multiply;
RotateFromLeft(node, leftOperator, thisOverOther);
}
}
}
}
else if (node.OperatorToken == leftOperator.OperatorToken
&& (node.OperatorToken == JsToken.BitwiseAnd || node.OperatorToken == JsToken.BitwiseOr || node.OperatorToken == JsToken.BitwiseXor))
{
// identical bitwise operators can be combined
JsConstantWrapper newLiteral = null;
switch (node.OperatorToken)
{
case JsToken.BitwiseAnd:
newLiteral = BitwiseAnd(otherConstant, thisConstant);
break;
case JsToken.BitwiseOr:
newLiteral = BitwiseOr(otherConstant, thisConstant);
break;
case JsToken.BitwiseXor:
newLiteral = BitwiseXor(otherConstant, thisConstant);
break;
}
if (newLiteral != null)
{
RotateFromLeft(node, leftOperator, newLiteral);
}
}
}
private void EvalToTheRight(JsBinaryOperator node, JsConstantWrapper thisConstant, JsConstantWrapper otherConstant, JsBinaryOperator rightOperator)
{
if (node.OperatorToken == JsToken.Plus)
{
if (rightOperator.OperatorToken == JsToken.Plus && otherConstant.IsStringLiteral)
{
// plus-plus, and the other constant is a string. So the right operator will be a string-concat
// that generates a string. And since this is a plus-operator, then this operator will be a string-
// concat as well. So we can just combine the strings now and replace our node with the right-hand
// operation
JsConstantWrapper newLiteral = StringConcat(thisConstant, otherConstant);
if (newLiteral != null)
{
RotateFromRight(node, rightOperator, newLiteral);
}
}
else if (rightOperator.OperatorToken == JsToken.Minus && !thisConstant.IsStringLiteral)
{
// plus-minus. Now, the minus operation happens first, and it will perform a numeric
// operation. The plus is NOT string, so that means it will also be a numeric operation
// and we can combine the operators numericly.
JsConstantWrapper newLiteral = NumericAddition(thisConstant, otherConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
RotateFromRight(node, rightOperator, newLiteral);
}
else
{
JsConstantWrapper rightRight = rightOperator.Operand2 as JsConstantWrapper;
if (rightRight != null)
{
EvalFarToTheRight(node, thisConstant, rightRight, rightOperator);
}
}
}
}
else if (node.OperatorToken == JsToken.Minus && rightOperator.OperatorToken == JsToken.Minus)
{
// minus-minus
// both operations are numeric, so we can combine the constant operands. However, we
// can't combine them into a plus, so make sure we do the minus in the opposite direction
JsConstantWrapper newLiteral = Minus(otherConstant, thisConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
rightOperator.SwapOperands();
RotateFromLeft(node, rightOperator, newLiteral);
}
else
{
JsConstantWrapper rightRight = rightOperator.Operand2 as JsConstantWrapper;
if (rightRight != null)
{
EvalFarToTheRight(node, thisConstant, rightRight, rightOperator);
}
}
}
else if (node.OperatorToken == JsToken.Multiply
&& (rightOperator.OperatorToken == JsToken.Multiply || rightOperator.OperatorToken == JsToken.Divide))
{
// multiply-divide or multiply-multiply
// multiply the operands and use the right-hand operator
JsConstantWrapper newLiteral = Multiply(thisConstant, otherConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, newLiteral))
{
RotateFromRight(node, rightOperator, newLiteral);
}
}
else if (node.OperatorToken == JsToken.Divide)
{
if (rightOperator.OperatorToken == JsToken.Multiply)
{
// divide-multiply
JsConstantWrapper newLiteral = Divide(thisConstant, otherConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, newLiteral)
&& newLiteral.ToCode().Length < thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// flip the operator: multiply becomes divide; devide becomes multiply
rightOperator.OperatorToken = JsToken.Divide;
RotateFromRight(node, rightOperator, newLiteral);
}
}
else if (rightOperator.OperatorToken == JsToken.Divide)
{
// divide-divide
// get constants for left/right and for right/left
JsConstantWrapper leftOverRight = Divide(thisConstant, otherConstant);
JsConstantWrapper rightOverLeft = Divide(otherConstant, thisConstant);
// get the lengths of the resulting code
int leftOverRightLength = leftOverRight != null ? leftOverRight.ToCode().Length : int.MaxValue;
int rightOverLeftLength = rightOverLeft != null ? rightOverLeft.ToCode().Length : int.MaxValue;
// try whichever is smaller
if (leftOverRight != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, leftOverRight)
&& (rightOverLeft == null || leftOverRightLength < rightOverLeftLength))
{
// use left-over-right.
// but only if the resulting value is smaller than the original expression
if (leftOverRightLength <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// We don't need to swap the operands, but we do need to switch the operator
rightOperator.OperatorToken = JsToken.Multiply;
RotateFromRight(node, rightOperator, leftOverRight);
}
}
else if (rightOverLeft != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, rightOverLeft))
{
// but only if the resulting value is smaller than the original expression
if (rightOverLeftLength <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// use right-over-left. Keep the operator, but swap the operands
rightOperator.SwapOperands();
RotateFromLeft(node, rightOperator, rightOverLeft);
}
}
}
}
}
public void Visit(JsConstantWrapper node)
{
// it's a constant, so we don't care
}
private JsAstNode ParseSwitchStatement()
{
JsContext switchCtx = m_currentToken.Clone();
JsAstNode expr = null;
JsAstNodeList cases = null;
var braceOnNewLine = false;
JsContext braceContext = null;
m_blockType.Add(BlockType.Switch);
try
{
// read switch(expr)
GetNextToken();
if (JsToken.LeftParenthesis != m_currentToken.Token)
ReportError(JsError.NoLeftParenthesis);
GetNextToken();
m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
m_noSkipTokenSet.Add(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
try
{
expr = ParseExpression();
if (JsToken.RightParenthesis != m_currentToken.Token)
{
ReportError(JsError.NoRightParenthesis);
}
GetNextToken();
if (JsToken.LeftCurly != m_currentToken.Token)
{
ReportError(JsError.NoLeftCurly);
}
braceOnNewLine = m_foundEndOfLine;
braceContext = m_currentToken.Clone();
GetNextToken();
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet, exc) == -1
&& IndexOfToken(NoSkipTokenSet.s_SwitchNoSkipTokenSet, exc) == -1)
{
// give up
exc._partiallyComputedNode = null;
throw;
}
else
{
if (exc._partiallyComputedNode == null)
expr = new JsConstantWrapper(true, JsPrimitiveType.Boolean, CurrentPositionContext(), this);
else
expr = exc._partiallyComputedNode;
if (IndexOfToken(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet, exc) != -1)
{
if (exc._token == JsToken.RightParenthesis)
GetNextToken();
if (JsToken.LeftCurly != m_currentToken.Token)
{
ReportError(JsError.NoLeftCurly);
}
braceOnNewLine = m_foundEndOfLine;
braceContext = m_currentToken.Clone();
GetNextToken();
}
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
}
// parse the switch body
cases = new JsAstNodeList(CurrentPositionContext(), this);
bool defaultStatement = false;
m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockNoSkipTokenSet);
try
{
while (JsToken.RightCurly != m_currentToken.Token)
{
JsSwitchCase caseClause = null;
JsAstNode caseValue = null;
var caseCtx = m_currentToken.Clone();
JsContext colonContext = null;
m_noSkipTokenSet.Add(NoSkipTokenSet.s_CaseNoSkipTokenSet);
try
{
if (JsToken.Case == m_currentToken.Token)
{
// get the case
GetNextToken();
caseValue = ParseExpression();
}
else if (JsToken.Default == m_currentToken.Token)
{
// get the default
if (defaultStatement)
{
// we report an error but we still accept the default
ReportError(JsError.DupDefault, true);
}
else
{
defaultStatement = true;
}
GetNextToken();
}
else
{
// This is an error, there is no case or default. Assume a default was missing and keep going
defaultStatement = true;
ReportError(JsError.BadSwitch);
}
if (JsToken.Colon != m_currentToken.Token)
{
ReportError(JsError.NoColon);
}
else
{
colonContext = m_currentToken.Clone();
}
// read the statements inside the case or default
GetNextToken();
}
catch (RecoveryTokenException exc)
{
// right now we can only get here for the 'case' statement
if (IndexOfToken(NoSkipTokenSet.s_CaseNoSkipTokenSet, exc) == -1)
{
// ignore the current case or default
exc._partiallyComputedNode = null;
throw;
}
else
{
caseValue = exc._partiallyComputedNode;
if (exc._token == JsToken.Colon)
{
GetNextToken();
}
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_CaseNoSkipTokenSet);
}
m_blockType.Add(BlockType.Block);
try
{
var statements = new JsBlock(m_currentToken.Clone(), this);
m_noSkipTokenSet.Add(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
m_noSkipTokenSet.Add(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
try
{
while (JsToken.RightCurly != m_currentToken.Token && JsToken.Case != m_currentToken.Token && JsToken.Default != m_currentToken.Token)
{
try
{
// parse a Statement, not a SourceElement
statements.Append(ParseStatement(false));
}
catch (RecoveryTokenException exc)
{
if (exc._partiallyComputedNode != null)
{
statements.Append(exc._partiallyComputedNode);
exc._partiallyComputedNode = null;
}
if (IndexOfToken(NoSkipTokenSet.s_StartStatementNoSkipTokenSet, exc) == -1)
{
throw;
}
}
}
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_SwitchNoSkipTokenSet, exc) == -1)
{
caseClause = new JsSwitchCase(caseCtx, this)
{
CaseValue = caseValue,
ColonContext = colonContext,
Statements = statements
};
cases.Append(caseClause);
throw;
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_StartStatementNoSkipTokenSet);
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_SwitchNoSkipTokenSet);
}
caseCtx.UpdateWith(statements.Context);
caseClause = new JsSwitchCase(caseCtx, this)
{
CaseValue = caseValue,
ColonContext = colonContext,
Statements = statements
};
cases.Append(caseClause);
}
finally
{
m_blockType.RemoveAt(m_blockType.Count - 1);
}
}
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_BlockNoSkipTokenSet, exc) == -1)
{
//save what you can a rethrow
switchCtx.UpdateWith(CurrentPositionContext());
exc._partiallyComputedNode = new JsSwitch(switchCtx, this)
{
Expression = expr,
BraceContext = braceContext,
Cases = cases,
BraceOnNewLine = braceOnNewLine
};
throw;
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockNoSkipTokenSet);
}
switchCtx.UpdateWith(m_currentToken);
GetNextToken();
}
finally
{
m_blockType.RemoveAt(m_blockType.Count - 1);
}
return new JsSwitch(switchCtx, this)
{
Expression = expr,
BraceContext = braceContext,
Cases = cases,
BraceOnNewLine = braceOnNewLine
};
}
/// <summary>
/// Return true if the result isn't an overflow condition
/// </summary>
/// <param name="result">result constant</param>
/// <returns>true is not an overflow; false if it is</returns>
private static bool NoOverflow(JsConstantWrapper result)
{
return !result.IsInfinity;
}
private JsConstantWrapper BitwiseXor(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
try
{
Int32 lValue = left.ToInt32();
Int32 rValue = right.ToInt32();
newLiteral = new JsConstantWrapper(Convert.ToDouble(lValue ^ rValue), JsPrimitiveType.Number, null, m_parser);
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
}
return newLiteral;
}
//---------------------------------------------------------------------------------------
// ParseWhileStatement
//
// WhileStatement :
// 'while' '(' Expression ')' Statement
//---------------------------------------------------------------------------------------
private JsWhileNode ParseWhileStatement()
{
JsContext whileCtx = m_currentToken.Clone();
JsAstNode condition = null;
JsAstNode body = null;
m_blockType.Add(BlockType.Loop);
try
{
GetNextToken();
if (JsToken.LeftParenthesis != m_currentToken.Token)
{
ReportError(JsError.NoLeftParenthesis);
}
GetNextToken();
m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
try
{
condition = ParseExpression();
if (JsToken.RightParenthesis != m_currentToken.Token)
{
ReportError(JsError.NoRightParenthesis);
whileCtx.UpdateWith(condition.Context);
}
else
whileCtx.UpdateWith(m_currentToken);
GetNextToken();
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet, exc) == -1)
{
// abort the while there is really no much to do here
exc._partiallyComputedNode = null;
throw;
}
else
{
// make up a condition
if (exc._partiallyComputedNode != null)
condition = exc._partiallyComputedNode;
else
condition = new JsConstantWrapper(false, JsPrimitiveType.Boolean, CurrentPositionContext(), this);
if (JsToken.RightParenthesis == m_currentToken.Token)
GetNextToken();
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
}
// if this is an assignment, throw a warning in case the developer
// meant to use == instead of =
// but no warning if the condition is wrapped in parens.
var binOp = condition as JsBinaryOperator;
if (binOp != null && binOp.OperatorToken == JsToken.Assign)
{
condition.Context.HandleError(JsError.SuspectAssignment);
}
// if the statements aren't withing curly-braces, throw a possible error
if (JsToken.LeftCurly != m_currentToken.Token)
{
ReportError(JsError.StatementBlockExpected, CurrentPositionContext(), true);
}
try
{
// parse a Statement, not a SourceElement
// and ignore any important comments that spring up right here.
body = ParseStatement(false, true);
}
catch (RecoveryTokenException exc)
{
if (exc._partiallyComputedNode != null)
body = exc._partiallyComputedNode;
else
body = new JsBlock(CurrentPositionContext(), this);
exc._partiallyComputedNode = new JsWhileNode(whileCtx, this)
{
Condition = condition,
Body = JsAstNode.ForceToBlock(body)
};
throw;
}
}
finally
{
m_blockType.RemoveAt(m_blockType.Count - 1);
}
return new JsWhileNode(whileCtx, this)
{
Condition = condition,
Body = JsAstNode.ForceToBlock(body)
};
}
private static string ComputeJoin(JsArrayLiteral arrayLiteral, JsConstantWrapper separatorNode)
{
// if the separator node is null, then the separator is a single comma character.
// otherwise it's just the string value of the separator.
var separator = separatorNode == null ? "," : separatorNode.ToString();
var sb = new StringBuilder();
for (var ndx = 0; ndx < arrayLiteral.Elements.Count; ++ndx)
{
// add the separator between items (if we have one)
if (ndx > 0 && !string.IsNullOrEmpty(separator))
{
sb.Append(separator);
}
// the element is a constant wrapper (we wouldn't get this far if it wasn't),
// but we've overloaded the virtual ToString method on ConstantWrappers to convert the
// constant value to a string value.
sb.Append(arrayLiteral.Elements[ndx].ToString());
}
return sb.ToString();
}
private JsConstantWrapper LogicalOr(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
try
{
// if the left-hand side evaluates to true, return the left-hand side.
// if the left-hand side is false, return the right-hand side.
newLiteral = left.ToBoolean() ? left : right;
}
catch (InvalidCastException)
{
// if we couldn't cast to bool, ignore
}
}
return newLiteral;
}
private JsConstantWrapper Plus(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (left.IsStringLiteral || right.IsStringLiteral)
{
// one or both are strings -- this is a strng concat operation
newLiteral = StringConcat(left, right);
}
else
{
// neither are strings -- this is a numeric addition operation
newLiteral = NumericAddition(left, right);
}
return newLiteral;
}
//---------------------------------------------------------------------------------------
// ParseWithStatement
//
// WithStatement :
// 'with' '(' Expression ')' Statement
//---------------------------------------------------------------------------------------
private JsWithNode ParseWithStatement()
{
JsContext withCtx = m_currentToken.Clone();
JsAstNode obj = null;
JsBlock block = null;
m_blockType.Add(BlockType.Block);
try
{
GetNextToken();
if (JsToken.LeftParenthesis != m_currentToken.Token)
ReportError(JsError.NoLeftParenthesis);
GetNextToken();
m_noSkipTokenSet.Add(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
try
{
obj = ParseExpression();
if (JsToken.RightParenthesis != m_currentToken.Token)
{
withCtx.UpdateWith(obj.Context);
ReportError(JsError.NoRightParenthesis);
}
else
withCtx.UpdateWith(m_currentToken);
GetNextToken();
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet, exc) == -1)
{
// give up
exc._partiallyComputedNode = null;
throw;
}
else
{
if (exc._partiallyComputedNode == null)
obj = new JsConstantWrapper(true, JsPrimitiveType.Boolean, CurrentPositionContext(), this);
else
obj = exc._partiallyComputedNode;
withCtx.UpdateWith(obj.Context);
if (exc._token == JsToken.RightParenthesis)
GetNextToken();
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BlockConditionNoSkipTokenSet);
}
// if the statements aren't withing curly-braces, throw a possible error
if (JsToken.LeftCurly != m_currentToken.Token)
{
ReportError(JsError.StatementBlockExpected, CurrentPositionContext(), true);
}
try
{
// parse a Statement, not a SourceElement
// and ignore any important comments that spring up right here.
JsAstNode statement = ParseStatement(false, true);
// but make sure we save it as a block
block = statement as JsBlock;
if (block == null)
{
block = new JsBlock(statement.Context, this);
block.Append(statement);
}
}
catch (RecoveryTokenException exc)
{
if (exc._partiallyComputedNode == null)
{
block = new JsBlock(CurrentPositionContext(), this);
}
else
{
block = exc._partiallyComputedNode as JsBlock;
if (block == null)
{
block = new JsBlock(exc._partiallyComputedNode.Context, this);
block.Append(exc._partiallyComputedNode);
}
}
exc._partiallyComputedNode = new JsWithNode(withCtx, this)
{
WithObject = obj,
Body = block
};
throw;
}
}
finally
{
m_blockType.RemoveAt(m_blockType.Count - 1);
}
return new JsWithNode(withCtx, this)
{
WithObject = obj,
Body = block
};
}
public void Visit(JsConstantWrapper node)
{
// not applicable; terminate
}
public void Visit(JsConstantWrapper node)
{
// not applicable; terminate
}
public void Visit(JsConstantWrapper node)
{
// we're good
}
//---------------------------------------------------------------------------------------
// MemberExpression
//
// Accessor :
// <empty> |
// Arguments Accessor
// '[' Expression ']' Accessor |
// '.' Identifier Accessor |
//
// Don't have this function throwing an exception without checking all the calling sites.
// There is state in instance variable that is saved on the calling stack in some function
// (i.e ParseFunction and ParseClass) and you don't want to blow up the stack
//---------------------------------------------------------------------------------------
private JsAstNode MemberExpression(JsAstNode expression, List<JsContext> newContexts)
{
for (; ; )
{
m_noSkipTokenSet.Add(NoSkipTokenSet.s_MemberExprNoSkipTokenSet);
try
{
switch (m_currentToken.Token)
{
case JsToken.LeftParenthesis:
JsAstNodeList args = null;
RecoveryTokenException callError = null;
m_noSkipTokenSet.Add(NoSkipTokenSet.s_ParenToken);
try
{
args = ParseExpressionList(JsToken.RightParenthesis);
}
catch (RecoveryTokenException exc)
{
args = (JsAstNodeList)exc._partiallyComputedNode;
if (IndexOfToken(NoSkipTokenSet.s_ParenToken, exc) == -1)
callError = exc; // thrown later on
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_ParenToken);
}
expression = new JsCallNode(expression.Context.CombineWith(args.Context), this)
{
Function = expression,
Arguments = args,
InBrackets = false
};
if (null != newContexts && newContexts.Count > 0)
{
(newContexts[newContexts.Count - 1]).UpdateWith(expression.Context);
if (!(expression is JsCallNode))
{
expression = new JsCallNode(newContexts[newContexts.Count - 1], this)
{
Function = expression,
Arguments = new JsAstNodeList(CurrentPositionContext(), this)
};
}
else
{
expression.Context = newContexts[newContexts.Count - 1];
}
((JsCallNode)expression).IsConstructor = true;
newContexts.RemoveAt(newContexts.Count - 1);
}
if (callError != null)
{
callError._partiallyComputedNode = expression;
throw callError;
}
GetNextToken();
break;
case JsToken.LeftBracket:
m_noSkipTokenSet.Add(NoSkipTokenSet.s_BracketToken);
try
{
//
// ROTOR parses a[b,c] as a call to a, passing in the arguments b and c.
// the correct parse is a member lookup on a of c -- the "b,c" should be
// a single expression with a comma operator that evaluates b but only
// returns c.
// So we'll change the default behavior from parsing an expression list to
// parsing a single expression, but returning a single-item list (or an empty
// list if there is no expression) so the rest of the code will work.
//
//args = ParseExpressionList(JSToken.RightBracket);
GetNextToken();
args = new JsAstNodeList(CurrentPositionContext(), this);
JsAstNode accessor = ParseExpression();
if (accessor != null)
{
args.Append(accessor);
}
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_BracketToken, exc) == -1)
{
if (exc._partiallyComputedNode != null)
{
exc._partiallyComputedNode =
new JsCallNode(expression.Context.CombineWith(m_currentToken.Clone()), this)
{
Function = expression,
Arguments = (JsAstNodeList)exc._partiallyComputedNode,
InBrackets = true
};
}
else
{
exc._partiallyComputedNode = expression;
}
throw;
}
else
args = (JsAstNodeList)exc._partiallyComputedNode;
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_BracketToken);
}
expression = new JsCallNode(expression.Context.CombineWith(m_currentToken.Clone()), this)
{
Function = expression,
Arguments = args,
InBrackets = true
};
// there originally was code here in the ROTOR sources that checked the new context list and
// changed this member call to a constructor call, effectively combining the two. I believe they
// need to remain separate.
// remove the close bracket token
GetNextToken();
break;
case JsToken.AccessField:
JsConstantWrapper id = null;
JsContext nameContext = m_currentToken.Clone();
GetNextToken();
if (JsToken.Identifier != m_currentToken.Token)
{
string identifier = JsKeyword.CanBeIdentifier(m_currentToken.Token);
if (null != identifier)
{
// don't report an error here -- it's actually okay to have a property name
// that is a keyword which is okay to be an identifier. For instance,
// jQuery has a commonly-used method named "get" to make an ajax request
//ForceReportInfo(JSError.KeywordUsedAsIdentifier);
id = new JsConstantWrapper(identifier, JsPrimitiveType.String, m_currentToken.Clone(), this);
}
else if (JsScanner.IsValidIdentifier(m_currentToken.Code))
{
// it must be a keyword, because it can't technically be an identifier,
// but it IS a valid identifier format. Throw a warning but still
// create the constant wrapper so we can output it as-is
ReportError(JsError.KeywordUsedAsIdentifier, m_currentToken.Clone(), true);
id = new JsConstantWrapper(m_currentToken.Code, JsPrimitiveType.String, m_currentToken.Clone(), this);
}
else
{
ReportError(JsError.NoIdentifier);
SkipTokensAndThrow(expression);
}
}
else
{
id = new JsConstantWrapper(m_scanner.Identifier, JsPrimitiveType.String, m_currentToken.Clone(), this);
}
GetNextToken();
expression = new JsMember(expression.Context.CombineWith(id.Context), this)
{
Root = expression,
Name = id.Context.Code,
NameContext = nameContext.CombineWith(id.Context)
};
break;
default:
if (null != newContexts)
{
while (newContexts.Count > 0)
{
(newContexts[newContexts.Count - 1]).UpdateWith(expression.Context);
expression = new JsCallNode(newContexts[newContexts.Count - 1], this)
{
Function = expression,
Arguments = new JsAstNodeList(CurrentPositionContext(), this)
};
((JsCallNode)expression).IsConstructor = true;
newContexts.RemoveAt(newContexts.Count - 1);
}
}
return expression;
}
}
catch (RecoveryTokenException exc)
{
if (IndexOfToken(NoSkipTokenSet.s_MemberExprNoSkipTokenSet, exc) != -1)
expression = exc._partiallyComputedNode;
else
{
Debug.Assert(exc._partiallyComputedNode == expression);
throw;
}
}
finally
{
m_noSkipTokenSet.Remove(NoSkipTokenSet.s_MemberExprNoSkipTokenSet);
}
}
}
public override void Visit(JsMember node)
{
if (node != null)
{
// depth-first
base.Visit(node);
if (string.CompareOrdinal(node.Name, "length") == 0
&& m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateLiteralLengths))
{
// if we create a constant, we'll replace the current node with it
JsConstantWrapper length = null;
JsArrayLiteral arrayLiteral;
var constantWrapper = node.Root as JsConstantWrapper;
if (constantWrapper != null)
{
if (constantWrapper.PrimitiveType == JsPrimitiveType.String && !constantWrapper.MayHaveIssues)
{
length = new JsConstantWrapper(constantWrapper.ToString().Length, JsPrimitiveType.Number, node.Context, node.Parser);
}
}
else if ((arrayLiteral = node.Root as JsArrayLiteral) != null && !arrayLiteral.MayHaveIssues)
{
// get the count of items in the array literal, create a constant wrapper from it, and
// replace this node with it
length = new JsConstantWrapper(arrayLiteral.Elements.Count, JsPrimitiveType.Number, node.Context, node.Parser);
}
if (length != null)
{
node.Parent.ReplaceChild(node, length);
}
}
}
}
/// <summary>
/// We have determined that our right-hand operand is another binary operator, and its
/// left-hand operand is a constant that can be combined with our left-hand operand.
/// Now we want to set the left-hand operand of that other operator to the newly-
/// combined constant value, and then rotate it up -- replace our binary operator
/// with this newly-modified binary operator, and then attempt to re-evaluate it.
/// </summary>
/// <param name="binaryOp">the binary operator that is our right-hand operand</param>
/// <param name="newLiteral">the newly-combined literal</param>
/// <param name="node"></param>
private void RotateFromRight(JsBinaryOperator node, JsBinaryOperator binaryOp, JsConstantWrapper newLiteral)
{
// replace our node with the binary operator
binaryOp.Operand1 = newLiteral;
node.Parent.ReplaceChild(node, binaryOp);
// and just for good measure.. revisit the node that's taking our place, since
// we just changed a constant value. Assuming the other operand is a constant, too.
JsConstantWrapper otherConstant = binaryOp.Operand2 as JsConstantWrapper;
if (otherConstant != null)
{
EvalThisOperator(binaryOp, newLiteral, otherConstant);
}
}
/// <summary>
/// If the new literal is a string literal, then we need to check to see if our
/// parent is a CallNode. If it is, and if the string literal can be an identifier,
/// we'll replace it with a Member-Dot operation.
/// </summary>
/// <param name="newLiteral">newLiteral we intend to replace this binaryop node with</param>
/// <returns>true if we replaced the parent callnode with a member-dot operation</returns>
/// <param name="node"></param>
private bool ReplaceMemberBracketWithDot(JsBinaryOperator node, JsConstantWrapper newLiteral)
{
if (newLiteral.IsStringLiteral)
{
// see if this newly-combined string is the sole argument to a
// call-brackets node. If it is and the combined string is a valid
// identifier (and not a keyword), then we can replace the call
// with a member operator.
// remember that the parent of the argument won't be the call node -- it
// will be the ast node list representing the arguments, whose parent will
// be the node list.
JsCallNode parentCall = (node.Parent is JsAstNodeList ? node.Parent.Parent as JsCallNode : null);
if (parentCall != null && parentCall.InBrackets)
{
// get the newly-combined string
string combinedString = newLiteral.ToString();
// see if this new string is the target of a replacement operation
string newName;
if (m_parser.Settings.HasRenamePairs && m_parser.Settings.ManualRenamesProperties
&& m_parser.Settings.IsModificationAllowed(JsTreeModifications.PropertyRenaming)
&& !string.IsNullOrEmpty(newName = m_parser.Settings.GetNewName(combinedString)))
{
// yes, it is. Now see if the new name is safe to be converted to a dot-operation.
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.BracketMemberToDotMember)
&& JsScanner.IsSafeIdentifier(newName)
&& !JsScanner.IsKeyword(newName, parentCall.EnclosingScope.UseStrict))
{
// we want to replace the call with operator with a new member dot operation, and
// since we won't be analyzing it (we're past the analyze phase, we're going to need
// to use the new string value
JsMember replacementMember = new JsMember(parentCall.Context, m_parser)
{
Root = parentCall.Function,
Name = newName,
NameContext = parentCall.Arguments[0].Context
};
parentCall.Parent.ReplaceChild(parentCall, replacementMember);
return true;
}
else
{
// nope, can't be changed to a dot-operator for whatever reason.
// just replace the value on this new literal. The old operation will
// get replaced with this new literal
newLiteral.Value = newName;
// and make sure it's type is string
newLiteral.PrimitiveType = JsPrimitiveType.String;
}
}
else if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.BracketMemberToDotMember))
{
// our parent is a call-bracket -- now we just need to see if the newly-combined
// string can be an identifier
if (JsScanner.IsSafeIdentifier(combinedString) && !JsScanner.IsKeyword(combinedString, parentCall.EnclosingScope.UseStrict))
{
// yes -- replace the parent call with a new member node using the newly-combined string
JsMember replacementMember = new JsMember(parentCall.Context, m_parser)
{
Root = parentCall.Function,
Name = combinedString,
NameContext = parentCall.Arguments[0].Context
};
parentCall.Parent.ReplaceChild(parentCall, replacementMember);
return true;
}
}
}
}
return false;
}
private JsConstantWrapper StringConcat(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
// if we don't want to combine adjacent string literals, then we know we don't want to do
// anything here.
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.CombineAdjacentStringLiterals))
{
// if either one of the operands is not a string literal, then check to see if we allow
// evaluation of numeric expression; if not, then no-go. IF they are both string literals,
// then it doesn't matter what the numeric flag says.
if ((left.IsStringLiteral && right.IsStringLiteral)
|| m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
// if either value is a floating-point number (a number, not NaN, not Infinite, not an Integer),
// then we won't do the string concatenation because different browsers may have subtle differences
// in their double-to-string conversion algorithms.
// so if neither is a numeric literal, or if one or both are, if they are both integer literals
// in the range that we can EXACTLY represent them in a double, then we can proceed.
// NaN, +Infinity and -Infinity are also acceptable
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new JsConstantWrapper(left.ToString() + right.ToString(), JsPrimitiveType.String, null, m_parser);
}
}
}
return newLiteral;
}
private JsConstantWrapper StrictNotEqual(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
JsPrimitiveType leftType = left.PrimitiveType;
if (leftType == right.PrimitiveType)
{
// the values are the same type
switch (leftType)
{
case JsPrimitiveType.Null:
// null !== null is false
newLiteral = new JsConstantWrapper(false, JsPrimitiveType.Boolean, null, m_parser);
break;
case JsPrimitiveType.Boolean:
// compare boolean values
newLiteral = new JsConstantWrapper(left.ToBoolean() != right.ToBoolean(), JsPrimitiveType.Boolean, null, m_parser);
break;
case JsPrimitiveType.String:
// compare string ordinally
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new JsConstantWrapper(string.CompareOrdinal(left.ToString(), right.ToString()) != 0, JsPrimitiveType.Boolean, null, m_parser);
}
break;
case JsPrimitiveType.Number:
try
{
// compare the values
// +0 and -0 are treated as "equal" in C#, so we don't need to test them separately.
// and NaN is always unequal to everything else, including itself.
if (left.IsOkayToCombine && right.IsOkayToCombine)
{
newLiteral = new JsConstantWrapper(left.ToNumber() != right.ToNumber(), JsPrimitiveType.Boolean, null, m_parser);
}
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
break;
}
}
else
{
// if they aren't the same type, they are not equal
newLiteral = new JsConstantWrapper(true, JsPrimitiveType.Boolean, null, m_parser);
}
}
return newLiteral;
}
public void Visit(JsConstantWrapper node)
{
if (node != null)
{
// allow string, number, true, false, and null.
switch (node.PrimitiveType)
{
case JsPrimitiveType.Boolean:
m_writer.Write((bool)node.Value ? "true" : "false");
break;
case JsPrimitiveType.Null:
m_writer.Write("null");
break;
case JsPrimitiveType.Number:
OutputNumber((double)node.Value, node.Context);
break;
case JsPrimitiveType.String:
case JsPrimitiveType.Other:
// string -- or treat it like a string
OutputString(node.Value.ToString());
break;
}
}
}
private JsConstantWrapper UnsignedRightShift(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
try
{
// left-hand value is a 32-bit signed integer
UInt32 lvalue = left.ToUInt32();
// mask only the bottom 5 bits of the right-hand value
int rvalue = (int)(right.ToUInt32() & 0x1F);
// convert the result to a double
double result = Convert.ToDouble(lvalue >> rvalue);
newLiteral = new JsConstantWrapper(result, JsPrimitiveType.Number, null, m_parser);
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
}
return newLiteral;
}
public override void Visit(JsConstantWrapper node)
{
if (node != null)
{
// measure
if (node.PrimitiveType == JsPrimitiveType.Boolean)
{
if (m_measure)
{
// if we are converting true/false literals to !0/!1, then
// a logical-not doesn't add or subtract anything. But if we aren't,
// we need to add/subtract the difference in the length between the
// "true" and "false" strings
if (!m_parser.Settings.MinifyCode
|| !m_parser.Settings.IsModificationAllowed(JsTreeModifications.BooleanLiteralsToNotOperators))
{
// converting true to false adds a character, false to true subtracts
m_delta += node.ToBoolean() ? 1 : -1;
}
}
else
{
// convert - just flip the boolean value
node.Value = !node.ToBoolean();
}
}
else
{
// just the same typical operation as most other nodes for other types
TypicalHandler(node);
}
}
}
/// <summary>
/// Return true is not an overflow or underflow, for multiplication operations
/// </summary>
/// <param name="left">left operand</param>
/// <param name="right">right operand</param>
/// <param name="result">result</param>
/// <returns>true if result not overflow or underflow; false if it is</returns>
private static bool NoMultiplicativeOverOrUnderFlow(JsConstantWrapper left, JsConstantWrapper right, JsConstantWrapper result)
{
// check for overflow
bool okayToProceed = !result.IsInfinity;
// if we still might be good, check for possible underflow
if (okayToProceed)
{
// if the result is zero, we might have an underflow. But if one of the operands
// was zero, then it's okay.
// Inverse: if neither operand is zero, then a zero result is not okay
okayToProceed = !result.IsZero || (left.IsZero || right.IsZero);
}
return okayToProceed;
}
private void EvalFarToTheLeft(JsBinaryOperator node, JsConstantWrapper thisConstant, JsConstantWrapper otherConstant, JsBinaryOperator leftOperator)
{
if (leftOperator.OperatorToken == JsToken.Minus)
{
if (node.OperatorToken == JsToken.Plus)
{
// minus-plus
// the minus will be a numeric operator, but if this constant is a string, it will be a
// string concatenation and we can't combine it.
if (thisConstant.PrimitiveType != JsPrimitiveType.String && thisConstant.PrimitiveType != JsPrimitiveType.Other)
{
JsConstantWrapper newLiteral = NumericAddition(otherConstant, thisConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
RotateFromRight(node, leftOperator, newLiteral);
}
}
}
else if (node.OperatorToken == JsToken.Minus)
{
// minus-minus
JsConstantWrapper newLiteral = Minus(otherConstant, thisConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
RotateFromRight(node, leftOperator, newLiteral);
}
}
}
else if (node.OperatorToken == JsToken.Multiply)
{
if (leftOperator.OperatorToken == JsToken.Multiply || leftOperator.OperatorToken == JsToken.Divide)
{
JsConstantWrapper newLiteral = Multiply(otherConstant, thisConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, newLiteral))
{
RotateFromRight(node, leftOperator, newLiteral);
}
}
}
else if (node.OperatorToken == JsToken.Divide)
{
if (leftOperator.OperatorToken == JsToken.Divide)
{
// divide-divide
JsConstantWrapper newLiteral = Divide(otherConstant, thisConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, newLiteral)
&& newLiteral.ToCode().Length <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
RotateFromRight(node, leftOperator, newLiteral);
}
}
else if (leftOperator.OperatorToken == JsToken.Multiply)
{
// mult-divide
JsConstantWrapper otherOverThis = Divide(otherConstant, thisConstant);
JsConstantWrapper thisOverOther = Divide(thisConstant, otherConstant);
int otherOverThisLength = otherOverThis != null ? otherOverThis.ToCode().Length : int.MaxValue;
int thisOverOtherLength = thisOverOther != null ? thisOverOther.ToCode().Length : int.MaxValue;
if (otherOverThis != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, otherOverThis)
&& (thisOverOther == null || otherOverThisLength < thisOverOtherLength))
{
if (otherOverThisLength <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
RotateFromRight(node, leftOperator, otherOverThis);
}
}
else if (thisOverOther != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, thisOverOther))
{
if (thisOverOtherLength <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// swap the operands
leftOperator.SwapOperands();
// operator is the opposite
leftOperator.OperatorToken = JsToken.Divide;
RotateFromLeft(node, leftOperator, thisOverOther);
}
}
}
}
}
/// <summary>
/// replace the node with a literal. If the node was wrapped in a grouping operator
/// before (parentheses around it), then we can get rid of the parentheses too, since
/// we are replacing the node with a single literal entity.
/// </summary>
/// <param name="node">node to replace</param>
/// <param name="newLiteral">literal to replace the node with</param>
private static void ReplaceNodeWithLiteral(JsAstNode node, JsConstantWrapper newLiteral)
{
var grouping = node.Parent as JsGroupingOperator;
if (grouping != null)
{
// because we are replacing the operator with a literal, the parentheses
// the grouped this operator are now superfluous. Replace them, too
grouping.Parent.ReplaceChild(grouping, newLiteral);
}
else
{
// just replace the node with the literal
node.Parent.ReplaceChild(node, newLiteral);
}
}
private void EvalFarToTheRight(JsBinaryOperator node, JsConstantWrapper thisConstant, JsConstantWrapper otherConstant, JsBinaryOperator rightOperator)
{
if (rightOperator.OperatorToken == JsToken.Minus)
{
if (node.OperatorToken == JsToken.Plus)
{
// plus-minus
// our constant cannot be a string, though
if (!thisConstant.IsStringLiteral)
{
JsConstantWrapper newLiteral = Minus(otherConstant, thisConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
RotateFromLeft(node, rightOperator, newLiteral);
}
}
}
else if (node.OperatorToken == JsToken.Minus)
{
// minus-minus
JsConstantWrapper newLiteral = NumericAddition(thisConstant, otherConstant);
if (newLiteral != null && NoOverflow(newLiteral))
{
// but we need to swap the left and right operands first
rightOperator.SwapOperands();
// then rotate the node up after replacing old with new
RotateFromRight(node, rightOperator, newLiteral);
}
}
}
else if (node.OperatorToken == JsToken.Multiply)
{
if (rightOperator.OperatorToken == JsToken.Multiply)
{
// mult-mult
JsConstantWrapper newLiteral = Multiply(thisConstant, otherConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, newLiteral))
{
RotateFromLeft(node, rightOperator, newLiteral);
}
}
else if (rightOperator.OperatorToken == JsToken.Divide)
{
// mult-divide
JsConstantWrapper otherOverThis = Divide(otherConstant, thisConstant);
JsConstantWrapper thisOverOther = Divide(thisConstant, otherConstant);
int otherOverThisLength = otherOverThis != null ? otherOverThis.ToCode().Length : int.MaxValue;
int thisOverOtherLength = thisOverOther != null ? thisOverOther.ToCode().Length : int.MaxValue;
if (otherOverThis != null && NoMultiplicativeOverOrUnderFlow(otherConstant, thisConstant, otherOverThis)
&& (thisOverOther == null || otherOverThisLength < thisOverOtherLength))
{
if (otherOverThisLength <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// swap the operands, but keep the operator
RotateFromLeft(node, rightOperator, otherOverThis);
}
}
else if (thisOverOther != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, thisOverOther))
{
if (thisOverOtherLength <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// swap the operands and opposite operator
rightOperator.SwapOperands();
rightOperator.OperatorToken = JsToken.Multiply;
RotateFromRight(node, rightOperator, thisOverOther);
}
}
}
}
else if (node.OperatorToken == JsToken.Divide)
{
if (rightOperator.OperatorToken == JsToken.Multiply)
{
// divide-mult
JsConstantWrapper newLiteral = Divide(thisConstant, otherConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, newLiteral)
&& newLiteral.ToCode().Length <= thisConstant.ToCode().Length + otherConstant.ToCode().Length + 1)
{
// swap the operands
rightOperator.SwapOperands();
// change the operator
rightOperator.OperatorToken = JsToken.Divide;
RotateFromRight(node, rightOperator, newLiteral);
}
}
else if (rightOperator.OperatorToken == JsToken.Divide)
{
// divide-divide
JsConstantWrapper newLiteral = Multiply(thisConstant, otherConstant);
if (newLiteral != null && NoMultiplicativeOverOrUnderFlow(thisConstant, otherConstant, newLiteral))
{
// but we need to swap the left and right operands first
rightOperator.SwapOperands();
// then rotate the node up after replacing old with new
RotateFromRight(node, rightOperator, newLiteral);
}
}
}
}
private JsConstantWrapper Divide(JsConstantWrapper left, JsConstantWrapper right)
{
JsConstantWrapper newLiteral = null;
if (left.IsOkayToCombine && right.IsOkayToCombine
&& m_parser.Settings.IsModificationAllowed(JsTreeModifications.EvaluateNumericExpressions))
{
try
{
double leftValue = left.ToNumber();
double rightValue = right.ToNumber();
double result = leftValue / rightValue;
if (JsConstantWrapper.NumberIsOkayToCombine(result))
{
newLiteral = new JsConstantWrapper(result, JsPrimitiveType.Number, null, m_parser);
}
else
{
if (!left.IsNumericLiteral && JsConstantWrapper.NumberIsOkayToCombine(leftValue))
{
left.Parent.ReplaceChild(left, new JsConstantWrapper(leftValue, JsPrimitiveType.Number, left.Context, m_parser));
}
if (!right.IsNumericLiteral && JsConstantWrapper.NumberIsOkayToCombine(rightValue))
{
right.Parent.ReplaceChild(right, new JsConstantWrapper(rightValue, JsPrimitiveType.Number, right.Context, m_parser));
}
}
}
catch (InvalidCastException)
{
// some kind of casting in ToNumber caused a situation where we don't want
// to perform the combination on these operands
}
}
return newLiteral;
}
private void EvalThisOperator(JsBinaryOperator node, JsConstantWrapper left, JsConstantWrapper right)
{
// we can evaluate these operators if we know both operands are literal
// number, boolean, string or null
JsConstantWrapper newLiteral = null;
switch (node.OperatorToken)
{
case JsToken.Multiply:
newLiteral = Multiply(left, right);
break;
case JsToken.Divide:
newLiteral = Divide(left, right);
if (newLiteral != null && newLiteral.ToCode().Length > node.ToCode().Length)
{
// the result is bigger than the expression.
// eg: 1/3 is smaller than .333333333333333
// never mind.
newLiteral = null;
}
break;
case JsToken.Modulo:
newLiteral = Modulo(left, right);
if (newLiteral != null && newLiteral.ToCode().Length > node.ToCode().Length)
{
// the result is bigger than the expression.
// eg: 46.5%6.3 is smaller than 2.4000000000000012
// never mind.
newLiteral = null;
}
break;
case JsToken.Plus:
newLiteral = Plus(left, right);
break;
case JsToken.Minus:
newLiteral = Minus(left, right);
break;
case JsToken.LeftShift:
newLiteral = LeftShift(left, right);
break;
case JsToken.RightShift:
newLiteral = RightShift(left, right);
break;
case JsToken.UnsignedRightShift:
newLiteral = UnsignedRightShift(left, right);
break;
case JsToken.LessThan:
newLiteral = LessThan(left, right);
break;
case JsToken.LessThanEqual:
newLiteral = LessThanOrEqual(left, right);
break;
case JsToken.GreaterThan:
newLiteral = GreaterThan(left, right);
break;
case JsToken.GreaterThanEqual:
newLiteral = GreaterThanOrEqual(left, right);
break;
case JsToken.Equal:
newLiteral = Equal(left, right);
break;
case JsToken.NotEqual:
newLiteral = NotEqual(left, right);
break;
case JsToken.StrictEqual:
newLiteral = StrictEqual(left, right);
break;
case JsToken.StrictNotEqual:
newLiteral = StrictNotEqual(left, right);
break;
case JsToken.BitwiseAnd:
newLiteral = BitwiseAnd(left, right);
break;
case JsToken.BitwiseOr:
newLiteral = BitwiseOr(left, right);
break;
case JsToken.BitwiseXor:
newLiteral = BitwiseXor(left, right);
break;
case JsToken.LogicalAnd:
newLiteral = LogicalAnd(left, right);
break;
case JsToken.LogicalOr:
newLiteral = LogicalOr(left, right);
break;
default:
// an operator we don't want to evaluate
break;
}
// if we can combine them...
if (newLiteral != null)
{
// first we want to check if the new combination is a string literal, and if so, whether
// it's now the sole parameter of a member-bracket call operator. If so, instead of replacing our
// binary operation with the new constant, we'll replace the entire call with a member-dot
// expression
if (!ReplaceMemberBracketWithDot(node, newLiteral))
{
ReplaceNodeWithLiteral(node, newLiteral);
}
}
}
public void Visit(JsConstantWrapper node)
{
// it's a constant, so we don't care
}
public void Visit(JsConstantWrapper node)
{
// we're good
}
