renamed Isar/isar_output.ML to Thy/thy_output.ML;
tuned messages;
Antiquote.scan_arguments (moved from here);
moved ML context stuff to from Context to ML_Context;
structure ROOT =
struct
structure Nat =
struct
datatype nat = Zero_nat | Suc of nat;
end; (*struct Nat*)
structure Codegen =
struct
type 'a null = {null_ : 'a};
fun null (A_:'a null) = #null_ A_;
fun head (A_:'a null) (y :: xs) = y
| head (A_:'a null) [] = null A_;
val null_option : 'b option = NONE;
fun null_optiona () = {null_ = null_option} : ('b option) null ;;
val dummy : Nat.nat option =
head (null_optiona ()) [SOME (Nat.Suc Nat.Zero_nat), NONE];
end; (*struct Codegen*)
end; (*struct ROOT*)