private JSForLoop ReplaceWhileLoopAndEnumerator(JSWhileLoop wl, JSExpression backingStore, JSExpression enumerator, TypeInfo enumeratorType, string arrayMember, string lengthMember)
{
var loopId = _NextLoopId++;
var arrayVariableName = String.Format("a${0:x}", loopId);
var indexVariableName = String.Format("i${0:x}", loopId);
var lengthVariableName = String.Format("l${0:x}", loopId);
var currentPropertyReference = enumeratorType.Definition.Properties.First((p) => p.Name == "Current");
var currentPropertyInfo = enumeratorType.Source.GetProperty(currentPropertyReference);
var itemType = currentPropertyInfo.ReturnType;
var arrayType = new ArrayType(itemType);
var arrayVariable = new JSVariable(
arrayVariableName, arrayType, Function.Method.Reference,
JSDotExpression.New(backingStore, new JSStringIdentifier(arrayMember, arrayType))
);
var indexVariable = new JSVariable(
indexVariableName, TypeSystem.Int32, Function.Method.Reference,
JSLiteral.New(0)
);
var lengthVariable = new JSVariable(
lengthVariableName, TypeSystem.Int32, Function.Method.Reference,
JSDotExpression.New(backingStore, new JSStringIdentifier(lengthMember, TypeSystem.Int32))
);
var initializer = new JSVariableDeclarationStatement(
new JSBinaryOperatorExpression(
JSOperator.Assignment, arrayVariable, arrayVariable.DefaultValue, arrayVariable.IdentifierType
),
new JSBinaryOperatorExpression(
JSOperator.Assignment, indexVariable, indexVariable.DefaultValue, indexVariable.IdentifierType
),
new JSBinaryOperatorExpression(
JSOperator.Assignment, lengthVariable, lengthVariable.DefaultValue, lengthVariable.IdentifierType
)
);
var condition = new JSBinaryOperatorExpression(
JSBinaryOperator.LessThan,
indexVariable, lengthVariable, TypeSystem.Boolean
);
var increment = new JSUnaryOperatorExpression(
JSUnaryOperator.PostIncrement,
indexVariable, TypeSystem.Int32
);
var result = new JSForLoop(
initializer, condition, new JSExpressionStatement(increment),
wl.Statements.ToArray()
);
result.Index = wl.Index;
new PropertyAccessReplacer(
enumerator, new JSProperty(currentPropertyReference, currentPropertyInfo),
new JSIndexerExpression(
arrayVariable, indexVariable,
itemType
)
).Visit(result);
return result;
}
public void VisitNode(JSForLoop fl)
{
CheckLabel(fl);
BlockStack.Push(new EnclosingBlockEntry {
Block = fl,
ParentNode = ParentNode,
Depth = BlockStack.Count
});
try {
VisitChildren(fl);
} finally {
BlockStack.Pop();
}
}
public void NodeSelfAndChildrenRecursive () {
var fl3 = new JSForLoop(
new JSNullStatement(), new JSNullExpression(), new JSNullStatement(),
new JSExpressionStatement(new JSStringIdentifier("loop3 iteration"))
);
fl3.Index = 2;
var fl2 = new JSForLoop(
new JSNullStatement(), new JSNullExpression(), new JSNullStatement(),
new JSExpressionStatement(new JSStringIdentifier("loop2 iteration"))
);
fl2.Index = 1;
var fl1 = new JSForLoop(
new JSNullStatement(), new JSNullExpression(), new JSNullStatement(),
fl2
);
fl1.Index = 0;
var tree = new JSBlockStatement(
fl1,
fl3
);
DumpNodeSequence(tree.SelfAndChildrenRecursive);
}
public void VisitNode(JSWhileLoop whileLoop)
{
JSVariable initVariable = null, lastVariable = null;
JSBinaryOperator initOperator = null;
JSExpression initValue = null;
var prevEStmt = PreviousSibling as JSExpressionStatement;
var prevVDS = PreviousSibling as JSVariableDeclarationStatement;
if (prevEStmt != null) {
var boe = prevEStmt.Expression as JSBinaryOperatorExpression;
if (
(boe != null) &&
(boe.Operator is JSAssignmentOperator) &&
(boe.Left is JSVariable)
) {
initVariable = (JSVariable)boe.Left;
initOperator = boe.Operator;
initValue = boe.Right;
}
} else if (prevVDS != null) {
var decl = prevVDS.Declarations.FirstOrDefault(
(d) => !d.IsNull
);
if (decl != null) {
initVariable = (JSVariable)decl.Left;
initOperator = decl.Operator;
initValue = decl.Right;
}
}
var lastStatement = whileLoop.Statements.LastOrDefault();
while ((lastStatement != null) && (lastStatement.GetType() == typeof(JSBlockStatement)))
lastStatement = ((JSBlockStatement)lastStatement).Statements.LastOrDefault();
var lastExpressionStatement = lastStatement as JSExpressionStatement;
if (lastExpressionStatement != null) {
var lastUoe = lastExpressionStatement.Expression as JSUnaryOperatorExpression;
var lastBoe = lastExpressionStatement.Expression as JSBinaryOperatorExpression;
if ((lastUoe != null) && (lastUoe.Operator is JSUnaryMutationOperator)) {
lastVariable = lastUoe.Expression as JSVariable;
} else if ((lastBoe != null) && (lastBoe.Operator is JSAssignmentOperator)) {
lastVariable = lastBoe.Left as JSVariable;
if (
(lastVariable != null) &&
!lastBoe.Right.AllChildrenRecursive.Any(
(n) => lastVariable.Equals(n)
)
) {
lastVariable = null;
}
}
}
var lastIfStatement = lastStatement as JSIfStatement;
if (
(lastIfStatement != null) &&
whileLoop.Condition is JSBooleanLiteral &&
((JSBooleanLiteral)whileLoop.Condition).Value
) {
var innerStatement = lastIfStatement.TrueClause;
while (innerStatement is JSBlockStatement) {
var bs = (JSBlockStatement)innerStatement;
if (bs.Statements.Count != 1) {
innerStatement = null;
break;
}
innerStatement = bs.Statements[0];
}
var eStmt = innerStatement as JSExpressionStatement;
if (eStmt != null) {
var breakExpr = eStmt.Expression as JSBreakExpression;
if ((breakExpr != null) && (breakExpr.TargetLabel == whileLoop.Label)) {
whileLoop.ReplaceChildRecursive(lastIfStatement, new JSNullStatement());
var doLoop = new JSDoLoop(
new JSUnaryOperatorExpression(JSOperator.LogicalNot, lastIfStatement.Condition),
whileLoop.Statements.ToArray()
);
doLoop.Label = whileLoop.Label;
ParentNode.ReplaceChild(whileLoop, doLoop);
VisitChildren(doLoop);
return;
}
}
}
bool cantBeFor = false;
if ((initVariable != null) && (lastVariable != null) &&
!initVariable.Equals(lastVariable)
) {
cantBeFor = true;
} else if ((initVariable ?? lastVariable) == null) {
cantBeFor = true;
} else if (!whileLoop.Condition.AllChildrenRecursive.Any(
(n) => (initVariable ?? lastVariable).Equals(n)
)) {
cantBeFor = true;
}
if (!cantBeFor) {
JSStatement initializer = null, increment = null;
if (initVariable != null) {
initializer = PreviousSibling as JSStatement;
ParentNode.ReplaceChild(PreviousSibling, new JSNullStatement());
}
if (lastVariable != null) {
increment = lastExpressionStatement;
whileLoop.ReplaceChildRecursive(lastExpressionStatement, new JSNullStatement());
}
var forLoop = new JSForLoop(
initializer, whileLoop.Condition, increment,
whileLoop.Statements.ToArray()
);
forLoop.Label = whileLoop.Label;
ParentNode.ReplaceChild(whileLoop, forLoop);
VisitChildren(forLoop);
} else {
VisitChildren(whileLoop);
}
}