/*  $Id: p_data.pl,v 1.15 2002/02/01 15:04:52 jan Exp $

    Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    Copyright (C): 1985-2002, University of Amsterdam

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    As a special exception, if you link this library with other files,
    compiled with a Free Software compiler, to produce an executable, this
    library does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however
    invalidate any other reasons why the executable file might be covered by
    the GNU General Public License.
*/



:- module(man_data,
	[
	]).

:- use_module(library(pce)).
:- use_module(util).
:- consult(classmap).
:- require([ absolute_file_name/3
	   , append/3
	   , between/3
	   , concat/3
	   , term_to_atom/2
	   ]).

%	find_module(+Name, +Create, -Module)
%
%	Find/create a manual module with the given name.  Bypasses
%	@manual to avoid having to use the GUI.

find_module(Name, Create, Module) :-
	new(Space, man_space(reference)),
	(   send(Space, ensure_loaded, Name)
	->  get(Space, module, Name, Module)
	;   Create == @on
	->  new(Module, man_module(Space, Name))
	;   fail
	).


		/********************************
		*     SPECIFIC MANUAL CARDS	*
		********************************/

:- pce_begin_class(man_class_card(identifier), man_card,
		   "Manual card of a class").

variable(user_interface,	string*,	get,
	 "Description of user interface").
variable(bugs,			string*,	get,
	 "Known bugs/anomalities").


initialise(C, Class:class) :->
	"Initialise from class"::
	send(C, send_super, initialise,
	     Class?man_module, Class?name, Class?man_id).


object(C, Class:class) :<-
	"Get associated class"::
	get(C, identifier, Name),
	name(Name, [0'C, 0'. | S0]),
	name(ClassName, S0),
	get(@classes, member, ClassName, Class).

:- pce_end_class.


:- pce_begin_class(man_variable_card(identifier), man_card,
		   "Manual card of an instance variable").

variable(defaults,	string*,	get, "Default value").

initialise(C, Var:variable) :->
	"Initialise from variable"::
	send(C, send_super, initialise,
	     Var?man_module, Var?name, Var?man_id).

object(C, Var:variable) :<-
	"Get associated instance variable"::
	get(C, identifier, Name),
	name(Name, [0'V, 0'. |S0]),
	append(S1, [0'.|S2], S0),
	name(ClassName, S1),
	name(VarName, S2),
	get(@classes, member, ClassName, Class),
	get(Class, instance_variable, VarName, Var).

:- pce_end_class.


:- pce_begin_class(man_method_card(identifier), man_card,
		   "Manual card of a method").

variable(diagnostics,	string*,	both,
	 "Possible error conditions/messages").
variable(defaults,	string*,	get,
	 "Default value").
variable(bugs,		string*,	get,
	 "Known problems").

initialise(C, M:method) :->
	"Initialise from method"::
	send(C, send_super, initialise, M?man_module, M?name, M?man_id).

object(C, Method:method) :<-
	"Get associated method"::
	get(C, identifier, Name),
	name(Name, [0'M, 0'. |S0]),
	append(S1, [0'.,T, 0'.|S2], S0),
	name(ClassName, S1),
	name(MethodName, S2),
	get(@classes, member, ClassName, Class),
	(   T == 0'S
	->  get(Class, send_method, MethodName, Method)
	;   get(Class, get_method, MethodName, Method)
	).

:- pce_end_class.


:- pce_begin_class(man_class_variable_card(identifier), man_card,
		   "Manual card of a class variable").

variable(defaults,	string*,	get,
	 "Default value").

initialise(C, R:class_variable) :->
	"Initialise from resource"::
	send(C, send_super, initialise, R?man_module, R?name, R?man_id).

object(C, R:class_variable) :<-
	"Get associated resource"::
	get(C, identifier, Name),
	name(Name, [0'R, 0'. |S0]),
	append(S1, [0'.|S2], S0),
	name(ClassName, S1),
	name(ResName, S2),
	get(@classes, member, ClassName, Class),
	get(Class, class_variable, ResName, R).

:- pce_end_class.


:- pce_begin_class(man_resource_card, man_class_variable_card,
		   "Backward compatibility handling").
:- pce_end_class.


:- pce_begin_class(man_error_card(identifier), man_card,
		   "Manual card of an error").


initialise(C, E:error) :->
	"Initialise from method"::
	send(C, send_super, initialise, E?man_module, E?id, E?man_id).


object(C, Error:error) :<-
	"Get associated error"::
	get(C, identifier, ManId),
	atom_concat('!.', ErrId, ManId),
	get(@pce, convert, ErrId, error, Error).

:- pce_end_class.


:- pce_begin_class(man_group_card(name), man_card,
		   "Describe functional group of methods").

variable(index, int, get, "Index to preserve the order").

initialise(G, Module:man_module, Name:name, Idx:int, Summary:[string]) :->
	"Initialise from group name"::
	send(G, send_super, initialise, Module, Name, Name),
	(   Summary \== @default
	->  send(G, store, summary, Summary)
	;   true
	),
	send(G, store, index, Idx).


object(G, Name:name) :<-
	"Get associated group name"::
	get(G, name, Name).

:- pce_end_class.


		/********************************
		*      OTHER MANUAL CARDS	*
		********************************/

:- pce_begin_class(man_topic_card(name), man_card,
		   "Hierarchical organisation on topics").

variable(super,		chain*,		get, "Super topic(s)").
variable(subs,		chain*,		get, "Sub topics").

man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = 'T'.

:- pce_end_class.


:- pce_begin_class(man_object_card(name), man_card,
		   "Description of global PCE object").

initialise(C, G:man_global) :->
	"Initialise from global object holder"::
	send(C, send_super, initialise, G?man_module, G?name, G?man_id).


man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = 'O'.


object(C, O:man_global) :<-
	"Get associated global object"::
	get(C, identifier, Name),
	atom_concat('O.', Reference, Name),
	new(O, man_global(Reference)).

delete_unreferenced(C) :->
	get(C, identifier, Name),
	(   atom_concat('O.', Reference, Name),
	    object(@Reference)
	->  true
	;   format(user_error, 'Deleting card ~w~n', [Name]),
	    free(C)
	).

:- pce_end_class.

:- pce_begin_class(man_predicate_card(name), man_card,
		   "Description of a Prolog predicate").

variable(diagnostics,	string*,	both,
	 "Possible error conditions/messages").

initialise(Card, M:man_module, Name:name) :->
	"Define id to be the predicate name"::
	send(Card, slot, name, Name),
	get(Card, predicate_name, Id),
	send(Card, send_super, initialise, M, Name, Id).


store(Card, Slot:name, Value:any) :->
	"Change id if name changes"::
	send(Card, send_super, store, Slot, Value),
	(   Slot == name
	->  get(Card, predicate_name, Id),
	    send(Card, identifier, Id)
	;   true
	).


man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = 'P'.

predicate_name(Card, PredName:name) :<-
	get(Card, name, Name),
	new(R, regex('\\(\\w+\\)')),
	send(R, search, Name),
	get(R, register_value, Name, 1, name, PredName).

:- pce_end_class.

:- pce_begin_class(man_example_card(name), man_card,
		   "Example code").

initialise(Card, M:man_module, Name:name) :->
	"Define id to be the predicate name"::
	send(Card, slot, name, Name),
	get(Card, id, Id),
	send(Card, send_super, initialise, M, Name, Id),
	send(Card, store, description, 'Enter description here'),
	send(Card, store, code, 'Enter code here').


store(Card, Slot:name, Value:any) :->
	"Change id if name changes"::
	send(Card, send_super, store, Slot, Value),
	(   Slot == name
	->  get(Card, id, Id),
	    send(Card, identifier, Id)
	;   true
	).


man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = 'E'.

variable(code,		string*,	both,
	 "Source code of example").

id(Card, Id) :<-
	get(Card, name, Name),
	new(S, string('%s', Name)),
	send(S, downcase),
	send(S, translate, ' ', '_'),
	get(S, value, Id).

:- pce_end_class.

:- pce_begin_class(man_browser_card(name), man_card,
		   "Documentation of a Manual Browser").

variable(tool_name,		name*,		both,
	 "Name of the tool documented").
variable(user_interface,	string*,	get,
	 "Description of UI behaviour").
variable(bugs,			string*,	get,
	 "Known problems").

man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = 'B'.

:- pce_end_class.

:- pce_begin_class(man_change_card(name), man_card,
		   "Documentation of a change to PCE").

man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = '~'.

:- pce_end_class.


:- pce_begin_class(man_bug_card(name), man_card,
		   "Documentation of a bug fix to PCE").

man_id(_Card, Id) :<-
	"Identifier of card type"::
	Id = '+'.

:- pce_end_class.


		/********************************
		*           MAN_GLOBAL		*
		********************************/

:- pce_global(@man_globals, new(hash_table)).

:- pce_begin_class(man_global(reference), object).

variable(reference,	name,	 get,	"Reference name of object").
variable(man_summary,	string,  get,	"Summary string (if available)").

initialise(G, Name:name, Summary:[string]*) :->
	"Create from name"::
	send(G, slot, reference, Name),
	(   (Summary == @default ; Summary == @nil)
	->  object_summary(Name, S)
	;   S = Summary
	),
	class_name(@Name, ClassName),
	send(G, slot, man_summary,
	     string('O\t@%s/%s\t%s', Name, ClassName, S)),
	send(@man_globals, append, Name, G).

lookup(_, Name:name, G) :<-
	"Lookup existing one"::
	get(@man_globals, member, Name, G).
			   

group(G, Group:name) :<-
	"Group (class name)"::
	get(G, reference, Reference),
	get(@Reference, '_class_name', Group).


summary(_G, _:string) :<-
	fail.

class_name(Ref, ClassName) :-
	object(Ref), !,
	get(Ref, '_class_name', ClassName).

object_summary(Name, Summary) :-
	object(@Name), !,
	(   get(@Name, '_class', Class),
	    get(Class, get_method, summary, _),
	    get(@Name, summary, Summary)
	->  true
	;   object(@Name, Term),
	    term_to_atom(Term, Summary)
	).


man_module(_G, Create:[bool], Module:man_module) :<-
	"objects module"::
	find_module(objects, Create, Module).

man_id(G, Id:name) :<-
	get('O.', append, G?reference, Id).


name(G, Name:name) :<-
	"@Reference"::
	get(G, reference, Reference),
	get(@, append, Reference, Name).


man_name(G, Name:string) :<-
	"Name for relation browser"::
	new(Name, string('O\t@%s', G?reference)).


man_card_class(_G, Class:class) :<-
	"Name for documentation card"::
	get(@pce, convert, man_object_card, class, Class).

context(G, Class:class) :<-
	"Return context class for jumping"::
	get(G, reference, Id),
	object(@Id),
	get(@Id, '_class', Class).

has_source(_G) :->
	"Just fail"::
	fail.

:- pce_end_class.


		/********************************
		*           EXTENSIONS		*
		********************************/

:- pce_extend_class(object).
:- pce_group(manual).

man_module_name(_Obj, Module) :<-
	"Module name for global objects"::
	Module = objects.


man_module(Obj, Create:[bool], Module) :<-
	"Module for global objects"::
	new(Space, man_space(reference)),
	get(Obj, man_module_name, ModuleName),
	(   get(Space, module, ModuleName, @on, Module)
	->  true
	;   Create == @on
	->  new(Module, man_module(Space, ModuleName))
	).


man_card(Obj, Create:[bool], Card) :<-
	"Manual card for object"::
	get(Obj, man_module, @on, Module),
	(   get(Module, card, Obj?man_id, Card)
	->  true
	;   Create == @on
	->  get(Obj, man_create_card, Card)
	).


man_documented(Obj) :->
	"Test if object is documented"::
	(   get(Obj, man_card, Card),
	    (   get(Card, description, Description), Description \== @nil
	    ;   get(Card, related, see_also, _)
	    )
	;   get(Obj, man_inherited_attribute, description, _)
	).


man_create_card(Obj, Card) :<-
	"Create manual card for object"::
	send(Obj, has_get_method, man_card_class),
	get(Obj?man_card_class, instance, Obj, Card).


man_attribute(Obj, Slot:name, Value:string*) :->
	"Store a slot of the manual card"::
	send(?(Obj, man_card, @on), store, Slot, Value).


man_attribute(Obj, Slot:name, Value) :<-
	"Fetch a manual attribute"::
	(   get(Obj, man_card, Card),
	    get(Card, fetch, Slot, Value)
	->  true
	;   send(Obj, has_get_method, Slot),
	    get(Obj, Slot, Value)
	),
	Value \== @nil.


man_inherited_attribute(Obj, Att:name, Tuple:tuple) :<-
	"Default inherited value"::
	(   get(Obj, man_inherit_object, Att, From),
	    get(From, man_attribute, Att, Value)
	->  new(Tuple, tuple(From, Value))
	;   get(Obj, man_card, Card),
	    get(Card, inherited_fetch, Att, Tuple)
	).


man_inherit_object(_Obj, _Att:name, _Obj2:object) :<-
	"Object from which to inherit attribute"::
	fail.


man_relate(Obj1, Type:name, Obj2:object) :->
	"Create a manual relation"::
	send(?(Obj1, man_card, @on), relate,
	     Type, ?(Obj2, man_card, @on)).


man_unrelate(Obj1, Type:name, Obj2:object) :->
	"Destroy a manual relation"::
	send(?(Obj1, man_card, @on), unrelate,
	     Type, ?(Obj2, man_card, @on)).


man_related(Obj1, Type:name, Obj2:object) :->
	"Create a manual relation"::
	send(?(Obj1, man_card), related, Type, Obj2?man_card).


man_related(Obj, Type:name, Chain) :<-
	"New chain with related objects"::
	get(?(?(Obj, man_card), related, Type), map,
	    new(?(@arg1, object)), Chain).


man_name(Obj, Name) :<-
	"Name for relation browser"::
	new(Name, string),
	send(Name, format, 'O\t@%s', Obj?object_reference).

man_creator(_Obj, _) :<-
	"Global default"::
	fail.

:- pce_end_class.

:- pce_extend_class(class).
:- pce_group(manual).

man_module_name(Class, Module) :<-
	"Manual module name for class"::
	get(Class, name, Name),
	(   mapped_class_name(Name, Mapped)
	;   Mapped = Name
	), !,
	atom_concat('class/', Mapped, Module).


man_card_class(_Class, Class:class) :<-
	"Manual card type"::
	get(@pce, convert, man_class_card, class, Class).


man_name(Class, Name:string) :<-
	"Name for relation browser"::
	new(Name, string('C\t%s', Class?name)).
	

has_source(Class) :->
	"Test if object may have associated sources"::
	\+ get(Class, creator, built_in).


source(Class, Loc:source_location) :<-
	"Find souce location of class definition"::
	get(Class, slot, source, Loc), Loc \== @nil,
	get(Loc, line_no, LineNo), LineNo \== @nil,
	fix_source_path(Loc).

fix_source_path(Loc) :-
	get(Loc, file_name, Name),
	send(file(Name), exists, @on), !.
fix_source_path(Loc) :-
	(   pce_host:property(system_source_prefix(Prefix)),
	    atom_codes(Prefix, PrefixChars),
	    get(Loc, file_name, Name),
	    atom_codes(Name, Chars),
	    append(_, S1, Chars),
	    append(PrefixChars, PwLocalChars, S1)
	->  atom_codes(PwLocal, PwLocalChars),
	    absolute_file_name(pce(PwLocal),
			       [ access(read)
			       ],
			       Path),
	    send(Loc, slot, file_name, Path)
	).

man_header(Class, Str:string) :<-
	"Header for class browser"::
	get(Class, name, ClassName),
	new(Str, string('%s(', ClassName)),
	get(Class, send_method, initialise, IM),
	get(IM, types, Types),
	get(Class, term_names, Names),
	append_arguments(Types, Names, Str),
	send(Str, append, ')').

append_arguments(Types, Names, Str) :-
	between(1, 10000, Idx),
	(   get(Types, element, Idx, Type)
	->  (Idx \== 1 -> send(Str, append, ', ') ; true),
	    get(Type, name, TypeName),
	    (   get(Type, argument_name, ArgName),
		ArgName \== @nil,
		ArgName \== TypeName
	    ->	send(Str, append, string('%s=%s', ArgName, TypeName))
	    ;   Names \== @nil,
	        get(Names, element, Idx, ArgName)
	    ->  send(Str, append, string('%s=%s', ArgName, TypeName))
	    ;   send(Str, append, TypeName)
	    ),
	    fail
	;   !
	).

man_delegate_header(Class, Str:string) :<-
	"Description of delegation behaviour"::
	new(Str, string),
	(   get(Class, delegate, Chain),
	    Chain \== @nil,
	    \+ send(Chain, empty)
	->  send(Chain, for_all,
		 and(if(Chain?head \== @arg1,
			message(Str, append, ', ')),
		     message(Str, append,
			     create(string, '%s (%s)',
				    @arg1?name, @arg1?type?name))))
	;   true
	).


man_creator(Class, Creator:name) :<-
	"Creator used by manual filters"::
	get(Class, creator, Creator).

:- pce_end_class.

:- pce_extend_class(variable).
:- pce_group(manual).

man_module_name(Var, Module) :<-
	"Manual module name for variable"::
	get(Var?context, man_module_name, Module).

man_card_class(_Var, Class:class) :<-
	"Manual card type"::
	get(@pce, convert, man_variable_card, class, Class).

man_name(Var, ManName:string) :<-
	"Name for relation browser"::
	get(Var, context_name, ClassName),
	get(Var, access_arrow, Arrow),
	get(Var, name, Name),
	new(ManName, string('V\t%s %s%s', ClassName, Arrow, Name)).
	

man_header(Var, Header:string) :<-
	"Header for card viewer"::
	get(Var, context_name, ClassName),
	get(Var, access_arrow, Arrow),
	get(Var, name, Name),
	get(Var, type, Type),
	get(Type, name, TypeName),
	new(Header, string('V\t%s %s%s: %s',
			   ClassName, Arrow, Name, TypeName)).

has_source(Var) :->
	"Test if object may have associated sources"::
	send(Var?context, has_source).

source(Var, Src) :<-
	"Find source (same as related class"::
	get(Var, context, Class), Class \== @nil,
	get(Class, source, Src).

man_inherit_object(Var, Att:name, R:class_variable) :<-
	"Lookup default in class-variable"::
	Att == defaults,
	get(Var?context, class_variable, Var?name, R).

man_creator(Var, Creator:name) :<-
	"<-creator of the <-context"::
	get(Var?context, creator, Creator).

:- pce_end_class.

super_class(Class, Super) :-
	get(Class, super_class, Super), Super \== @nil.
super_class(Class, Super) :-
	get(Class, super_class, Above), Above \== @nil,
	super_class(Above, Super).

:- pce_extend_class(method).
:- pce_group(manual).

man_module_name(M, Module) :<-
	"Manual module name for method"::
	get(M?context, man_module_name, Module).


man_card_class(_M, Class:class) :<-
	"Manual card type"::
	get(@pce, convert, man_method_card, class, Class).


has_source(M) :->
	"Test if object may have associated sources"::
	get(M, slot, source, Loc), Loc \== @nil,
	get(Loc, line_no, LineNo), LineNo \== @nil.


source(M, Loc) :<-
	"Find source definition"::
	get(M, slot, source, Loc), Loc \== @nil,
	get(Loc, line_no, LineNo), LineNo \== @nil,
	fix_source_path(Loc).


man_documented(M) :->
	"Look for inherited too"::
	(   send(M, send_super, man_documented)
	->  true
	;   get(M, context, Class),
	    get(M, name, Selector),
	    get(Class, instance_variable, Selector, Var),
	    send(Var, man_documented)
	).


man_creator(M, Creator:name) :<-
	"<-creator of the <-context"::
	get(M?context, creator, Creator).

:- pce_end_class.

:- pce_extend_class(error).
:- pce_group(manual).

man_module_name(_E, Module:name) :<-
	"Manual module name for method"::
	Module = errors.

summary(E, Summary:string) :<-
	get(E, format, Summary).

name(E, Name:name) :<-
	get(E, id, Name).

man_summary(E, Summary:string) :<-
	"Summary string"::
	get(E, slot, format, Format),
	new(Summary, string('!\t%s\t%s\t%s',
			    E?id, E?kind, Format)),
	send(Summary, translate, '\n', ' '),
	(   send(E, man_documented)
	->  send(Summary, append, ' (+)')
	;   true
	).

man_card_class(_E, Class:class) :<-
	"Manual card type"::
	get(@pce, convert, man_error_card, class, Class).

man_id(E, Id:name) :<-
	"Identifier of object"::
	get(E, id, ErrId),
	get('!.', append, ErrId, Id).

man_name(E, Name:name) :<-
	"Name for relation browser"::
	get(E, id, ErrId),
	get('! ', append, ErrId, Name).

man_creator(_E, Creator:name) :<-
	"For now, always returns built_in"::
	Creator = built_in.

:- pce_end_class.

%	Type pretty printing

method_types(M, Str) :-
	get(M, types, Types),
	get(Types, size, Size),
	(   Size > 0
	->  send(Str, append, ': ')
	;   true
	),
	between(1, Size, Arg),
	    get(Types, element, Arg, Type),
	    get(Type, fullname, Name),
	    send(Str, append, Name),
	    (	Arg < Size
	    ->	send(Str, append, ', ')
	    ;	true
	    ),
	fail ; true.


:- pce_extend_class(send_method).
:- pce_group(manual).

man_name(M, Name) :<-
	"Name for relation browser"::
	new(Name, string('M\t%s->%s', M?context?name, M?name)).
	

man_header(M, Header:string) :<-
	"Header for card browser"::
	get(M, context, Ctx),
	get(Ctx, name, ClassName),
	get(M, name, Name),
	new(Header, string('M\t%s->%s', ClassName, Name)),
	method_types(M, Header).


man_inherit_object(M, Att:name, Impl:behaviour) :<-
	"Inherit from variable if not available"::
	get(M, context, Class),
	get(M, name, Selector),
	(   get(Class, instance_variable, Selector, Impl)
	->  true
	;   super_class(Class, Super),
	    get(Super, send_method, Selector, Impl),
	    (   (  get(Impl, man_attribute, Att, _)
		;  \+ super_class(Super, _)
		)
	    ->  !
	    )
	).

:- pce_end_class.

:- pce_extend_class(get_method).
:- pce_group(manual).

man_name(M, Name) :<-
	"Name for relation browser"::
	new(Name, string),
	send(Name, format, 'M\t%s<-%s', M?context?name, M?name).
	
man_header(M, Header:string) :<-
	"Header for card browser"::
	get(M, context, Ctx),
	get(Ctx, name, ClassName),
	get(M, name, Name),
	new(Header, string('M\t%s<-%s', ClassName, Name)),
	method_types(M, Header),
	send(Header, append, ' ==>'),
	get(M, return_type, Type),
	get(Type, fullname, TypeName),
	send(Header, append, TypeName).

man_inherit_object(M, Att:name, Impl:'variable|method') :<-
	"Inherit from variable if not available"::
	get(M, context, Class),
	get(M, name, Selector),
	(   get(Class, instance_variable, Selector, Impl)
	->  true
	;   super_class(Class, Super),
	    get(Super, get_method, Selector, Impl),
	    (   (  get(Impl, man_attribute, Att, _)
		;  \+ super_class(Super, _)
		)
	    ->  !
	    )
	).


:- pce_end_class.

:- pce_extend_class(class_variable).
:- pce_group(manual).

man_module_name(R, Module) :<-
	"Manual module name for method"::
	get(R?context, man_module_name, Module).


man_card_class(_R, Class:class) :<-
	"Manual card type"::
	get(@pce, convert, man_class_variable_card, class, Class).


man_name(R, Name) :<-
	"Name for relation browser"::
	get(R, value, Value),
	portray_object(Value, Term),
	term_to_atom(Term, ValueDescription),
	new(Name, string('R\t%s.%s: %s',
			 R?context?name, R?name, ValueDescription)).
	

has_source(_R) :->
	"Test if object may have associated sources"::
	true.


man_attribute(R, Att:name, Value) :<-
	"Get default value of class variable"::
	(   Att == defaults
	->  get(R, default, Value)
	;   get(R, get_super, man_attribute, Att, Value)
	).


man_inherited_attribute(R, Att:name, Tuple:tuple) :<-
	"Inherit description from variable"::
	Att == description,
	get(R, context, Class),
	get(R, name, Selector),
	get(Class, instance_variable, Selector, Var),
	get(Var, man_attribute, Att, Value),
	new(Tuple, tuple(Var, Value)).


source(R, Src) :<-
	"Find source (same as related class"::
	get(R, context, Class),
	get(Class, source, Src).


man_creator(R, Creator:name) :<-
	"<-creator of the <-context"::
	get(R?context, creator, Creator).

:- pce_end_class.

