public override Type Infer(Environment env, Substitution subst)
{
try
{
var function = Function.Infer(env.Local(), subst);
var argument = Argument.Infer(env.Local(), subst);
var result = new TypeVariable();
function.Unify(new FunctionType(argument, result), subst);
return(result.Perform(subst));
}
catch (StackedException ex)
{
ex.Push("In an application expression: " + this);
throw;
}
}
public override Type Infer(Environment env, Substitution subst)
{
var constructor = env.Constructors[Constructor];
if (constructor.Arity != Arguments.Count)
{
throw new PatternArgumentCountException(constructor.Arity, Arguments.Count);
}
Type self = new TypeVariable();
var list = Arguments.Select(arg => arg.Infer(env, subst)).ToList();
var whole = list.Reverse <Type>().Aggregate(self, (res, arg) => new FunctionType(arg, res));
whole.Unify(constructor.Type.Instantiate(), subst);
return(self.Perform(subst));
}
public override Type Infer(Environment env, Substitution subst)
{
try
{
var value = Value.Infer(env.Local(), subst);
Type result = new TypeVariable();
foreach (var pattern in Patterns)
{
pattern.Unify(value, result, env, subst);
}
return(result.Perform(subst));
}
catch (StackedException ex)
{
ex.Push("In a match expression: " + this);
throw;
}
}