public virtual void SubstUnify(Type that, Substitution substitution)
{
if (this != that)
{
that.DoUnify(this, substitution);
}
}
public override void SubstUnify(Type that, Substitution substitution)
{
if (that != this)
{
that.DoUnify(this, substitution);
}
}
public override Type Instantiate()
{
var subst = new Substitution();
foreach (var arg in Arguments.Where(arg => arg.RigidName == null))
{
subst.Bind(arg, new TypeVariable());
}
return(Inner.Perform(subst));
}
public override Type Perform(Substitution substitution)
{
var local = substitution.Local();
foreach (var arg in Arguments)
{
local.Map = local.Map.Remove(arg);
}
return(new TypeScheme(Arguments, Inner.Perform(local)));
}
public override void DoUnify(TupleType var, Substitution substitution)
{
if (Arguments.Count != var.Arguments.Count)
{
throw TypeException.Create(this.Perform(substitution), var.Perform(substitution));
}
for (var i = 0; i < Arguments.Count; ++i)
{
Arguments[i].Perform(substitution).Unify(var.Arguments[i].Perform(substitution), substitution);
}
}
public override void UnifyWithRigid(TypeVariable var, Substitution substitution)
{
if (var == this)
{
return;
}
if (RigidName != null)
{
throw RigidTypeException.Create(RigidName, var);
}
substitution.Bind(this, var);
}
public override Type Perform(Substitution substitution)
{
if (!substitution.Map.ContainsKey(this))
{
return(this);
}
if (RigidName != null)
{
throw RigidTypeException.Create(RigidName, substitution.Map[this]);
}
return(substitution.Map[this].Perform(substitution));
}
public void Unify(Type that, Substitution substitution)
{
try
{
Perform(substitution).SubstUnify(that.Perform(substitution), substitution);
}
catch (StackedException ex)
{
var sb = new StringBuilder("While trying to unify ");
PrettyPrint(ex.PrettyPrinter, sb, 0);
sb.Append(" with ");
that.PrettyPrint(ex.PrettyPrinter, sb, 0);
ex.Push(sb.ToString());
throw;
}
}
public override void DoUnify(Type var, Substitution substitution)
{
if (this == var)
{
return;
}
if (RigidName != null)
{
var.UnifyWithRigid(this, substitution);
}
else
{
if (var.FreeVariables().Contains(this))
{
throw OccursCheckException.Create(var.Perform(substitution), this.Perform(substitution));
}
substitution.Bind(this, var);
}
}
public override void DoUnify(FunctionType var, Substitution substitution)
{
Argument.Perform(substitution).Unify(var.Argument.Perform(substitution), substitution);
Result.Perform(substitution).Unify(var.Result.Perform(substitution), substitution);
}
public override Type Perform(Substitution substitution)
{
return(new FunctionType(Argument.Perform(substitution), Result.Perform(substitution)));
}
public override void DoUnify(FloatingType var, Substitution substitution)
{
}
public override void DoUnify(CharacterType var, Substitution substitution)
{
}
public virtual void DoUnify(TupleType var, Substitution substitution)
{
DoUnify((Type)var, substitution);
}
public virtual void DoUnify(TypeVariable var, Substitution substitution)
{
var.DoUnify(this, substitution);
}
public override Type Perform(Substitution substitution)
{
return(new TupleType(Arguments.Select(x => x.Perform(substitution)).ToList()));
}
public virtual void DoUnify(FunctionType var, Substitution substitution)
{
DoUnify((Type)var, substitution);
}
public virtual void DoUnify(FloatingType var, Substitution substitution)
{
DoUnify((Type)var, substitution);
}
public virtual void DoUnify(CharacterType var, Substitution substitution)
{
DoUnify((Type)var, substitution);
}
public virtual void DoUnify(IntegralType var, Substitution substitution)
{
DoUnify((Type)var, substitution);
}
public override Type Perform(Substitution substitution)
{
return(this);
}
public override void DoUnify(IntegralType var, Substitution substitution)
{
}
public virtual void DoUnify(Type that, Substitution substitution)
{
throw TypeException.Create(Perform(substitution), that.Perform(substitution));
}
public abstract Type Perform(Substitution substitution);
public virtual void UnifyWithRigid(TypeVariable var, Substitution subst)
{
throw RigidTypeException.Create(var.RigidName, this);
}