--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Tools/list_code.ML Wed May 06 19:09:31 2009 +0200
@@ -0,0 +1,52 @@
+(* Author: Florian Haftmann, TU Muenchen
+
+Code generation for list literals.
+*)
+
+signature LIST_CODE =
+sig
+ val implode_list: string -> string -> Code_Thingol.iterm -> Code_Thingol.iterm list option
+ val default_list: int * string
+ -> (Code_Printer.fixity -> Code_Thingol.iterm -> Pretty.T)
+ -> Code_Printer.fixity -> Code_Thingol.iterm -> Code_Thingol.iterm -> Pretty.T
+ val add_literal_list: string -> theory -> theory
+end;
+
+structure List_Code : LIST_CODE =
+struct
+
+open Basic_Code_Thingol;
+
+fun implode_list nil' cons' t =
+ let
+ fun dest_cons (IConst (c, _) `$ t1 `$ t2) =
+ if c = cons'
+ then SOME (t1, t2)
+ else NONE
+ | dest_cons _ = NONE;
+ val (ts, t') = Code_Thingol.unfoldr dest_cons t;
+ in case t'
+ of IConst (c, _) => if c = nil' then SOME ts else NONE
+ | _ => NONE
+ end;
+
+fun default_list (target_fxy, target_cons) pr fxy t1 t2 =
+ Code_Printer.brackify_infix (target_fxy, Code_Printer.R) fxy [
+ pr (Code_Printer.INFX (target_fxy, Code_Printer.X)) t1,
+ Code_Printer.str target_cons,
+ pr (Code_Printer.INFX (target_fxy, Code_Printer.R)) t2
+ ];
+
+fun add_literal_list target =
+ let
+ fun pretty literals [nil', cons'] pr thm vars fxy [(t1, _), (t2, _)] =
+ case Option.map (cons t1) (implode_list nil' cons' t2)
+ of SOME ts =>
+ Code_Printer.literal_list literals (map (pr vars Code_Printer.NOBR) ts)
+ | NONE =>
+ default_list (Code_Printer.infix_cons literals) (pr vars) fxy t1 t2;
+ in Code_Target.add_syntax_const target
+ @{const_name Cons} (SOME (2, ([@{const_name Nil}, @{const_name Cons}], pretty)))
+ end
+
+end;