public override TypeSpec ResolveAsType(IMemberContext mc, bool allowUnboundTypeArguments = false)
{
var length = elements.Count;
if (length > 7)
{
throw new NotImplementedException("tuples > 7");
}
eclass = ExprClass.Type;
var otype = mc.Module.PredefinedTypes.Tuples [length - 1].Resolve();
if (otype == null)
{
return(null);
}
GenericTypeExpr ctype = new GenericTypeExpr(otype, elements, loc);
type = ctype.ResolveAsType(mc);
if (names != null && CheckElementNames(mc) && type != null)
{
type = NamedTupleSpec.MakeType(mc.Module, (InflatedTypeSpec)type, names);
}
return(type);
}
protected override Expression DoResolve(ResolveContext rc)
{
var src = source.Resolve(rc);
if (src == null)
{
return(null);
}
if (InternalType.HasNoType(src.Type))
{
rc.Report.Error(8131, source.Location, "Deconstruct assignment requires an expression with a type on the right-hand-side");
return(null);
}
var src_type = src.Type;
if (src_type.IsTupleType)
{
if (src_type.Arity != targetExprs.Count)
{
rc.Report.Error(8132, loc, "Cannot deconstruct a tuple of `{0}' elements into `{1}' variables",
src_type.Arity.ToString(), targetExprs.Count.ToString());
return(null);
}
var tupleLiteral = src as TupleLiteral;
if (tupleLiteral == null && !ExpressionAnalyzer.IsInexpensiveLoad(src))
{
var expr_variable = LocalVariable.CreateCompilerGenerated(source.Type, rc.CurrentBlock, loc);
source = new CompilerAssign(expr_variable.CreateReferenceExpression(rc, loc), source, loc);
instance = expr_variable.CreateReferenceExpression(rc, loc);
}
for (int i = 0; i < targetExprs.Count; ++i)
{
var tle = src_type.TypeArguments [i];
var lv = variablesToInfer? [i];
if (lv != null)
{
if (InternalType.HasNoType(tle))
{
rc.Report.Error(8130, Location, "Cannot infer the type of implicitly-typed deconstruction variable `{0}'", lv.Name);
lv.Type = InternalType.ErrorType;
continue;
}
lv.Type = tle;
lv.PrepareAssignmentAnalysis((BlockContext)rc);
}
var element_src = tupleLiteral == null ? new MemberAccess(instance, NamedTupleSpec.GetElementPropertyName(i)) : tupleLiteral.Elements [i].Expr;
targetExprs [i] = new SimpleAssign(targetExprs [i], element_src).Resolve(rc);
}
eclass = ExprClass.Value;
// TODO: The type is same only if there is no target element conversion
// var res = (/*byte*/ b, /*short*/ s) = (2, 4);
type = src.Type;
return(this);
}
if (src_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
{
rc.Report.Error(8133, loc, "Cannot deconstruct dynamic objects");
return(null);
}
/*
* var args = new Arguments (targetExprs.Count);
* foreach (var t in targetExprs) {
* args.Add (new Argument (t, Argument.AType.Out));
* }
*
* var invocation = new Invocation (new MemberAccess (src, "Deconstruct"), args);
* var res = invocation.Resolve (rc);
*/
throw new NotImplementedException("Custom deconstruct");
}
protected override Expression DoResolve(ResolveContext rc)
{
var src = source.Resolve(rc);
if (src == null)
{
return(null);
}
if (InternalType.HasNoType(src.Type))
{
rc.Report.Error(8131, source.Location, "Deconstruct assignment requires an expression with a type on the right-hand-side");
return(null);
}
var src_type = src.Type;
if (src_type.IsTupleType)
{
int target_count;
if (targetExprs == null)
{
target_count = variables.Count;
targetExprs = new List <Expression> (target_count);
}
else
{
target_count = targetExprs.Count;
}
if (src_type.Arity != target_count)
{
rc.Report.Error(8132, loc, "Cannot deconstruct a tuple of `{0}' elements into `{1}' variables",
src_type.Arity.ToString(CultureInfo.InvariantCulture), target_count.ToString(CultureInfo.InvariantCulture));
return(null);
}
var tupleLiteral = src as TupleLiteral;
if (tupleLiteral == null && !ExpressionAnalyzer.IsInexpensiveLoad(src))
{
var expr_variable = LocalVariable.CreateCompilerGenerated(source.Type, rc.CurrentBlock, loc);
source = new CompilerAssign(expr_variable.CreateReferenceExpression(rc, loc), source, loc);
instance = expr_variable.CreateReferenceExpression(rc, loc);
}
var element_srcs = new List <Expression> ();
var src_names = new List <string> ();
for (int i = 0; i < target_count; ++i)
{
var element_src = tupleLiteral == null ? new MemberAccess(instance, NamedTupleSpec.GetElementPropertyName(i)) : tupleLiteral.Elements [i].Expr;
element_srcs.Add(element_src);
if (element_src is VariableReference)
{
src_names.Add((element_src as VariableReference)?.Name);
}
}
for (int i = 0; i < target_count; ++i)
{
var tle = src_type.TypeArguments [i];
if (variables != null)
{
var variable = variables [i].Variable;
if (variable.Type == InternalType.Discard)
{
variables [i] = null;
targetExprs.Add(EmptyExpressionStatement.Instance);
continue;
}
var variable_type = variables [i].TypeExpression;
targetExprs.Add(new LocalVariableReference(variable, variable.Location));
if (variable_type is VarExpr)
{
if (InternalType.HasNoType(tle))
{
rc.Report.Error(8130, Location, "Cannot infer the type of implicitly-typed deconstruction variable `{0}'", variable.Name);
tle = InternalType.ErrorType;
}
variable.Type = tle;
}
else
{
variable.Type = variable_type.ResolveAsType(rc);
}
variable.PrepareAssignmentAnalysis((BlockContext)rc);
}
var element_target = (targetExprs [i] as SimpleName)?.LookupNameExpression(rc, MemberLookupRestrictions.None);
if (element_target != null && src_names.Contains((element_target as VariableReference)?.Name))
{
var tempType = element_target.Resolve(rc).Type;
var temp = new LocalTemporary(tempType);
tempExprs.Add(new SimpleAssign(temp, element_srcs [i]).Resolve(rc));
targetExprs [i] = new SimpleAssign(targetExprs [i], temp).Resolve(rc);
}
else
{
targetExprs [i] = new SimpleAssign(targetExprs [i], element_srcs [i]).Resolve(rc);
}
}
eclass = ExprClass.Value;
// TODO: The type is same only if there is no target element conversion
// var res = (/*byte*/ b, /*short*/ s) = (2, 4);
type = src.Type;
return(this);
}
if (src_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
{
rc.Report.Error(8133, loc, "Cannot deconstruct dynamic objects");
return(null);
}
/*
* var args = new Arguments (targetExprs.Count);
* foreach (var t in targetExprs) {
* args.Add (new Argument (t, Argument.AType.Out));
* }
*
* var invocation = new Invocation (new MemberAccess (src, "Deconstruct"), args);
* var res = invocation.Resolve (rc);
*/
throw new NotImplementedException("Custom deconstruct");
}