# HG changeset patch
# User wenzelm
# Date 1185980142 -7200
# Node ID 1b0bc10019a567078e777fd9ffeef46d99d5fd54
# Parent  ec9e75a46e164d06f630d18b565b145a24df3f5f
renamed config_option.ML to config.ML;
moved attrib setup to attrib.ML;

diff -r ec9e75a46e16 -r 1b0bc10019a5 src/Pure/config.ML
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/config.ML	Wed Aug 01 16:55:42 2007 +0200
@@ -0,0 +1,121 @@
+(*  Title:      Pure/config.ML
+    ID:         $Id$
+    Author:     Makarius
+
+Configuration options as values within the local context.
+*)
+
+signature CONFIG =
+sig
+  datatype value = Bool of bool | Int of int | String of string
+  val print_value: value -> string
+  val print_type: value -> string
+  type 'a T
+  val bool: value T -> bool T
+  val int: value T -> int T
+  val string: value T -> string T
+  val get: Proof.context -> 'a T -> 'a
+  val map: 'a T -> ('a -> 'a) -> Proof.context -> Proof.context
+  val put: 'a T -> 'a -> Proof.context -> Proof.context
+  val get_thy: theory -> 'a T -> 'a
+  val map_thy: 'a T -> ('a -> 'a) -> theory -> theory
+  val put_thy: 'a T -> 'a -> theory -> theory
+  val get_generic: Context.generic -> 'a T -> 'a
+  val map_generic: 'a T -> ('a -> 'a) -> Context.generic -> Context.generic
+  val put_generic: 'a T -> 'a -> Context.generic -> Context.generic
+  val declare: bool -> string -> value -> value T
+end;
+
+structure Config: CONFIG =
+struct
+
+(* simple 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 name f value =
+  let
+    val value' = f value;
+    val _ = same_type value value' orelse
+      error ("Ill-typed configuration option " ^ quote name ^ ": " ^
+        print_type value ^ " expected,\nbut " ^ print_type value' ^ " was found");
+  in value' end;
+
+
+(* abstract configuration options *)
+
+datatype 'a T = Config of
+ {get_value: Context.generic -> 'a,
+  map_value: ('a -> 'a) -> Context.generic -> Context.generic};
+
+fun coerce make dest (Config {get_value, map_value}) =
+  Config {get_value = dest o get_value, map_value = fn f => map_value (make o f o dest)};
+
+val bool = coerce Bool (fn Bool b => b);
+val int = coerce Int (fn Int i => i);
+val string = coerce String (fn String s => s);
+
+fun get_generic context (Config {get_value, ...}) = get_value context;
+fun map_generic (Config {map_value, ...}) f context = map_value f context;
+fun put_generic config value = map_generic config (K value);
+
+fun get_ctxt ctxt = get_generic (Context.Proof ctxt);
+fun map_ctxt config f = Context.proof_map (map_generic config f);
+fun put_ctxt config value = map_ctxt config (K value);
+
+fun get_thy thy = get_generic (Context.Theory thy);
+fun map_thy config f = Context.theory_map (map_generic config f);
+fun put_thy config value = map_thy config (K value);
+
+
+(* context information *)
+
+structure Value = GenericDataFun
+(
+  type T = value Inttab.table;
+  val empty = Inttab.empty;
+  val extend = I;
+  fun merge _ = Inttab.merge (K true);
+);
+
+fun declare global name default =
+  let
+    val id = serial ();
+
+    fun get_value context = the_default default (Inttab.lookup (Value.get context) id);
+    fun modify_value f = Value.map (Inttab.map_default (id, default) (type_check name f));
+
+    fun map_value f (context as Context.Proof _) =
+          let val context' = modify_value f context in
+            if global andalso
+              get_value (Context.Theory (Context.theory_of context')) <> get_value context'
+            then (warning ("Ignoring local change of global option " ^ quote name); context)
+            else context'
+          end
+      | map_value f context = modify_value f context;
+  in Config {get_value = get_value, map_value = map_value} end;
+
+
+(*final declarations of this structure!*)
+val get = get_ctxt;
+val map = map_ctxt;
+val put = put_ctxt;
+
+end;