public override BoundNode VisitFromEndIndexExpression(BoundFromEndIndexExpression node)
{
if (_inExpressionLambda)
{
Error(ErrorCode.ERR_ExpressionTreeContainsFromEndIndexExpression, node);
}
return(base.VisitFromEndIndexExpression(node));
}
public override BoundNode VisitFromEndIndexExpression(BoundFromEndIndexExpression node)
{
Debug.Assert(node.MethodOpt != null);
NamedTypeSymbol booleanType = _compilation.GetSpecialType(SpecialType.System_Boolean);
BoundExpression fromEnd = MakeLiteral(node.Syntax, ConstantValue.Create(true), booleanType);
BoundExpression operand = VisitExpression(node.Operand);
if (NullableNeverHasValue(operand))
{
operand = new BoundDefaultExpression(operand.Syntax, operand.Type !.GetNullableUnderlyingType());
}
operand = NullableAlwaysHasValue(operand) ?? operand;
if (!node.Type.IsNullableType())
{
return(new BoundObjectCreationExpression(node.Syntax, node.MethodOpt, operand, fromEnd));
}
ArrayBuilder <BoundExpression> sideeffects = ArrayBuilder <BoundExpression> .GetInstance();
ArrayBuilder <LocalSymbol> locals = ArrayBuilder <LocalSymbol> .GetInstance();
// operand.HasValue
operand = CaptureExpressionInTempIfNeeded(operand, sideeffects, locals);
BoundExpression condition = MakeOptimizedHasValue(operand.Syntax, operand);
// new Index(operand, fromEnd: true)
BoundExpression boundOperandGetValueOrDefault = MakeOptimizedGetValueOrDefault(operand.Syntax, operand);
BoundExpression indexCreation = new BoundObjectCreationExpression(node.Syntax, node.MethodOpt, boundOperandGetValueOrDefault, fromEnd);
// new Nullable(new Index(operand, fromEnd: true))
BoundExpression consequence = ConvertToNullable(node.Syntax, node.Type, indexCreation);
// default
BoundExpression alternative = new BoundDefaultExpression(node.Syntax, node.Type);
// operand.HasValue ? new Nullable(new Index(operand, fromEnd: true)) : default
BoundExpression conditionalExpression = RewriteConditionalOperator(
syntax: node.Syntax,
rewrittenCondition: condition,
rewrittenConsequence: consequence,
rewrittenAlternative: alternative,
constantValueOpt: null,
rewrittenType: node.Type,
isRef: false);
return(new BoundSequence(
syntax: node.Syntax,
locals: locals.ToImmutableAndFree(),
sideEffects: sideeffects.ToImmutableAndFree(),
value: conditionalExpression,
type: node.Type));
}
public override BoundNode VisitFromEndIndexExpression(BoundFromEndIndexExpression node)
{
Debug.Assert(node.MethodOpt != null);
//NamedTypeSymbol booleanType = _compilation.GetSpecialType(SpecialType.System_Boolean);
//BoundExpression fromEnd = MakeLiteral(node.Syntax, ConstantValue.Create(true), booleanType);
BoundExpression operand = VisitExpression(node.Operand);
if (NullableNeverHasValue(operand))
{
operand = new BoundDefaultExpression(operand.Syntax, operand.Type.GetNullableUnderlyingType());
}
operand = NullableAlwaysHasValue(operand) ?? operand;
if (!node.Type.IsNullableType())
{
var notOperand = new BoundUnaryOperator(node.Syntax, UnaryOperatorKind.IntBitwiseComplement, operand, null, null, LookupResultKind.Viable, ImmutableArray <MethodSymbol> .Empty, operand.Type);
return(new BoundObjectCreationExpression(node.Syntax, node.MethodOpt, binderOpt: null, notOperand));
}
throw new NotImplementedException("TODO: rewriter of BoundFromEndIndexExpression for ?int is not implemented");
ArrayBuilder <BoundExpression> sideeffects = ArrayBuilder <BoundExpression> .GetInstance();
ArrayBuilder <LocalSymbol> locals = ArrayBuilder <LocalSymbol> .GetInstance();
// operand.HasValue
operand = CaptureExpressionInTempIfNeeded(operand, sideeffects, locals);
BoundExpression condition = MakeOptimizedHasValue(operand.Syntax, operand);
// new Index(operand, fromEnd: true)
BoundExpression boundOperandGetValueOrDefault = MakeOptimizedGetValueOrDefault(operand.Syntax, operand);
BoundExpression indexCreation = new BoundObjectCreationExpression(node.Syntax, node.MethodOpt, binderOpt: null, boundOperandGetValueOrDefault);
if (!TryGetNullableMethod(node.Syntax, node.Type, SpecialMember.System_Nullable_T__ctor, out MethodSymbol nullableCtor))
{
return(BadExpression(node.Syntax, node.Type, operand));
}
// new Nullable(new Index(operand, fromEnd: true))
BoundExpression consequence = new BoundObjectCreationExpression(node.Syntax, nullableCtor, binderOpt: null, indexCreation);
// default
BoundExpression alternative = new BoundDefaultExpression(node.Syntax, constantValueOpt: null, node.Type);
// operand.HasValue ? new Nullable(new Index(operand, fromEnd: true)) : default
BoundExpression conditionalExpression = RewriteConditionalOperator(
syntax: node.Syntax,
rewrittenCondition: condition,
rewrittenConsequence: consequence,
rewrittenAlternative: alternative,
constantValueOpt: null,
rewrittenType: node.Type,
isRef: false);
return(new BoundSequence(
syntax: node.Syntax,
locals: locals.ToImmutableAndFree(),
sideEffects: sideeffects.ToImmutableAndFree(),
value: conditionalExpression,
type: node.Type));
}