public TypeSpecifier(TypeSpecifier returnType, TypeSpecifier[] parameterTypes)
{
if (returnType == null)
{
throw new OracularException ("return type invalid");
}
if (parameterTypes == null)
{
throw new OracularException ("parameter types invalid");
}
this.Type = SpecType.Function;
this.ReturnType = returnType;
this.ParameterTypes = parameterTypes;
}
public static TypeSpecifier GetFunction(TypeSpecifier returnType, TypeSpecifier[] parameterTypes)
{
return new TypeSpecifier (returnType, parameterTypes);
}
public TypeSpecifier Coalesce(TypeSpecifier other)
{
if (Type == SpecType.Any)
{
if (other.Type == SpecType.Any)
{
// both any, return any
return this;
}
// this is any, defer to other
return other;
}
if (Type != other.Type)
{
// distinct types, invalid
return null;
}
if (Type == SpecType.Table)
{
// both table types, check table names
return Table == other.Table ? this : null;
}
// same type
return this;
}