(* Title: Pure/config.ML
ID: $Id$
Author: Makarius
Configuration options as values within the local context. Global
environment of named options, with type declaration.
*)
signature CONFIG =
sig
datatype value = Bool of bool | Int of int | String of string
type 'a T
val get: Proof.context -> 'a T -> 'a
val get_thy: theory -> 'a T -> 'a
val get_generic: Context.generic -> 'a T -> 'a
val map: 'a T -> ('a -> 'a) -> Proof.context -> Proof.context
val map_thy: 'a T -> ('a -> 'a) -> theory -> theory
val map_generic: 'a T -> ('a -> 'a) -> Context.generic -> Context.generic
val put: 'a T -> 'a -> Proof.context -> Proof.context
val put_thy: 'a T -> 'a -> theory -> theory
val put_generic: 'a T -> 'a -> Context.generic -> Context.generic
val print_configs: Proof.context -> unit
val the_config: string -> value T * value
val bool: string -> bool -> bool T
val int: string -> int -> int T
val string: string -> string -> string T
end;
structure Config: CONFIG =
struct
(* mixed values *)
datatype value =
Bool of bool |
Int of int |
String of string;
fun print_value (Bool true) = "true"
| print_value (Bool false) = "false"
| print_value (Int i) = signed_string_of_int i
| print_value (String s) = quote s;
fun print_type (Bool _) = "boolean"
| print_type (Int _) = "integer"
| print_type (String _) = "string";
fun same_type (Bool _) (Bool _) = true
| same_type (Int _) (Int _) = true
| same_type (String _) (String _) = true
| same_type _ _ = false;
fun type_check f value =
let
val value' = f value;
val _ = same_type value value' orelse
error ("Ill-typed configuration option: " ^ print_type value ^
" expected,\nbut " ^ print_type value' ^ " was found");
in value' end;
structure ConfigData = GenericDataFun
(
type T = value Inttab.table;
val empty = Inttab.empty;
val extend = I;
fun merge _ = Inttab.merge (K true);
);
(* abstract configuration options *)
datatype 'a T = Config of
{get_value: Context.generic -> 'a,
map_value: ('a -> 'a) -> Context.generic -> Context.generic};
fun get_generic context (Config {get_value, ...}) = get_value context;
fun get_ctxt ctxt = get_generic (Context.Proof ctxt);
fun get_thy thy = get_generic (Context.Theory thy);
fun map_generic (Config {map_value, ...}) f context = map_value f context;
fun map_ctxt config f = Context.proof_map (map_generic config f);
fun map_thy config f = Context.theory_map (map_generic config f);
fun put_generic config value = map_generic config (K value);
fun put_ctxt config value = map_ctxt config (K value);
fun put_thy config value = map_thy config (K value);
(* global declarations *)
local val global_configs = ref (Symtab.empty: (value T * value) Symtab.table) in
fun print_configs ctxt =
let
fun prt (name, (config, default)) =
Pretty.block [Pretty.str (name ^ ": " ^ print_type default ^ " ="), Pretty.brk 1,
Pretty.str (print_value (get_ctxt ctxt config))];
val configs = sort_wrt #1 (Symtab.dest (! global_configs));
in Pretty.writeln (Pretty.big_list "configuration options" (map prt configs)) end;
fun the_config name =
(case Symtab.lookup (! global_configs) name of SOME cfg => cfg
| NONE => error ("Unknown configuration option " ^ quote name));
fun declare make dest name default =
let
val id = serial ();
val default_value = make default;
fun get_value context =
the_default default_value (Inttab.lookup (ConfigData.get context) id);
fun map_value f = ConfigData.map (Inttab.map_default (id, default_value) (type_check f));
val config_value = Config {get_value = get_value, map_value = map_value};
val _ = CRITICAL (fn () =>
(if Symtab.defined (! global_configs) name
then warning ("Hiding existing configuration option " ^ quote name) else ();
change global_configs (Symtab.update (name, (config_value, default_value)))));
in Config {get_value = dest o get_value, map_value = fn f => map_value (make o f o dest)} end;
end;
val bool = declare Bool (fn Bool b => b);
val int = declare Int (fn Int i => i);
val string = declare String (fn String s => s);
(*final declarations of this structure!*)
val get = get_ctxt;
val map = map_ctxt;
val put = put_ctxt;
end;