public TypeMatch TemplateMatchesInput(ComputationContext ctx, EntityInstance input,
VarianceMode variance, TypeMatching matching)
{
// todo: this is correct but it is just a hack really, because we should check constraints
// and if they are compatible we should return match
if (input.TargetsTemplateParameter && this.TargetsTemplateParameter &&
!input.TargetTemplate.Constraints.Any() && !this.TargetTemplate.Constraints.Any())
{
return(TypeMatch.Same);
}
matching.Position = matching.Position.Flipped(variance);
switch (matching.Position)
{
case VarianceMode.None:
return(this.IsExactlySame(input, jokerMatchesAll: true) ? TypeMatch.Same : TypeMatch.No);
case VarianceMode.In:
return(TypeMatcher.Matches(ctx, this, input, matching));
case VarianceMode.Out:
return(TypeMatcher.Matches(ctx, input, this, matching));
}
throw new NotImplementedException();
}
public ConstraintMatch ArgumentMatchesParameterConstraints(ComputationContext ctx, EntityInstance closedTemplate,
TemplateParameter param)
{
if (this.TargetsTemplateParameter && this.TemplateParameterTarget == param)
{
return(ConstraintMatch.Yes);
}
TypeMutability arg_mutability = this.SurfaceMutabilityOfType(ctx);
if (param.Constraint.Modifier.HasConst &&
arg_mutability != TypeMutability.ForceConst && arg_mutability != TypeMutability.ConstAsSource)
{
return(ConstraintMatch.MutabilityViolation);
}
else if (param.Constraint.Modifier.HasMutable && arg_mutability != TypeMutability.ForceMutable)
{
return(ConstraintMatch.MutabilityViolation);
}
else if (param.Constraint.Modifier.HasReassignable && !arg_mutability.HasFlag(TypeMutability.Reassignable))
{
return(ConstraintMatch.AssignabilityViolation);
}
// 'inherits' part of constraint
foreach (EntityInstance constraint_inherits in param.Constraint.TranslateInherits(closedTemplate))
{
TypeMatch match = TypeMatcher.Matches(ctx, this, constraint_inherits,
TypeMatching.Create(ctx.Env.Options.InterfaceDuckTyping, allowSlicing: true));
if (match.IsMismatch())
{
return(ConstraintMatch.InheritsViolation);
}
}
{
VirtualTable vtable = EntityInstanceExtension.BuildDuckVirtualTable(ctx, this, param.AssociatedType.InstanceOf,
allowPartial: false);
if (vtable == null)
{
return(ConstraintMatch.MissingFunction);
}
}
// 'base-of' part of constraint
IEnumerable <IEntityInstance> arg_bases = (this.TargetsTemplateParameter
? this.TargetType.TemplateParameter.Constraint.TranslateBaseOf(closedTemplate)
: Enumerable.Empty <EntityInstance>()
)
.Concat(this);
foreach (EntityInstance constraint_base in param.Constraint.TranslateBaseOf(closedTemplate))
{
if (!arg_bases.Any(it => !constraint_base.MatchesTarget(ctx, it, TypeMatching.Create(ctx.Env.Options.InterfaceDuckTyping, allowSlicing: true))
.IsMismatch()))
{
return(ConstraintMatch.BaseViolation);
}
}
return(ConstraintMatch.Yes);
}
public TypeMatch MatchesInput(ComputationContext ctx, EntityInstance input, TypeMatching matching)
{
return(TypeMatcher.Matches(ctx, input, this, matching));
}