1:- module( debug_call, 
    2        [ 
    3            debug_call/2,
    4            debug_call/3,
    5            debug_call/4,
    6            debuc/1, debuc/2, debuc/3, debuc/4,
    7            debug_chain/2, debug_chain/3,
    8            debug_consec/3, debug_consec/4,
    9            debug_message/3,
   10            debug_on/1,
   11            debug_portray/2,
   12            debug_set/2,
   13            debugging_status/2,
   14            debug_topic/2,
   15            debug_topic/3,
   16            debug_call_version/2,
   17            debugging_topic/1
   18       ] ).   19
   20:- multifile(user:message_property/2).   21:- dynamic(debug_call_message_property/2).   22
   23user:message_property( Dbg, Property ) :-
   24    debug_call_message_property( Dbg, Property ).

?- debug( ex ).
?- debug_call( ex, length, '', list1/[x,y,z] ).
% Length for list, list1: 3

?- debug_call( ex, length, 'some prefix', [list1,list2]/[[x,y,z],[a,b,c]] ).
% some prefix lengths for lists, list1: 3, list2: 3

?- debug_call( ex, dims, [m1,m2]/[[a(x),a(y),a(z)],[xy(a,b),xy(c,d),xy(e,f)]] ).
%  Dimensions for matrices,  (m1) nR: 3, nC: 1. (m2) nR: 3, nC: 2.

?- debug_call( ex, enum, testo/[a,b,c] ).
% Starting enumeration of list: testo
% 1.a
% 2.b
% 3.c
% Ended enumeration of list: testo
true.

?- debug_call( ex, info, 'My message is ~w.'/long ).
% My message is long.
true.    % message above is printed in informational colour

?- debug_call( ex, wrote, loc(file,csv) ).
% Could not locate wrote on file specified by: file, and extensions: csv
?- csv_write_file( 'file.csv', [] ).

?- debug_call( ex, wrote, loc(file,csv) ).
% Wrote on file: '/home/nicos/pl/lib/src/trace/file.csv'

?- debug_call( ex, task(stop), 'write on file' ).
At 15:44:1 on 2nd of Jul 2014 finished task: write on file.

?- assert( (simple_mess(KVs,Mess,Args):- KVs =[a=A,b=B], atom_concat(A,B,Mess), Args=[]) ).
?- debug_call( ex, simple_mess([a=1,b=2],

 debug_call_version(-Version, -Date)

Current version and release date for the library.

?- debug_call_version( -V, -D ).
V = 1:5:0,
D = date(2022,12,29).

*/

  107debug_call_version( 1:5:0, date(2022,12,29) ).
  108
  109:- use_module(library(apply)).   % maplist/4,...
  110:- use_module(library(lists)).   % member/4,...
  111:- use_module(library(debug)).   % debug/1,...
  112:- use_module(library(lib)).  113
  114:- lib(source(debug_call), [homonyms(true),index(false)]).  115:- lib(stoics_lib:locate/3 ).  116:- lib(stoics_lib:en_list/2).  117:- lib(stoics_lib:message_report/3).  118:- lib(stoics_lib:datime_readable/1).  119:- lib(end(debug_call) ).

 debuc(+Topic, +Goal)

 debuc(+Topic, +Goal, +Args)

 debuc(+Topic, +Goal, +Pfx, +Args)

Shorthands for debug_call/2,3,4 and debug/1.

author

- nicos angelopoulos

version

- 0:1 2020/9/9

  130debuc( Topic ) :-
  131    debug( Topic ).
  132debuc( Topic, Goal ) :-
  133    debug_call( Topic, Goal ).
  134debuc( Topic, Goal, Args ) :-
  135    debug_call( Topic, Goal, Args ).
  136debuc( Topic, Goal, Pfx, Args ) :-
  137    debug_call( Topic, Goal, Pfx, Args ).

 debug_call(+Topic, +Goal)

Only call debug if we are debugging Topic.

If Goal with arity +2 is available call that instead of Goal with extra arguments Mess and Args that will be passed to debug/3. If the goal (original or +2) fail, nothing is printed by debug_call and the debug_call(T,G) itself succeeds.

 ?- goal( Goal, Mess, Args ).

Examples

 ?- assert( (simple_mess(KVs,Mess,Args):- KVs =[a=A,b=B], atom_concat(A,B,Mess), Args=[]) ).
 ?- debug_call( ex, simple_mess([a=1,b=2],

author

- nicos angelopoulos

version

- 0.2 2018/3/20

  160debug_call( Topic, Goal ) :-
  161    debugging_topic( Topic ),
  162    !,
  163    debug_call_goal( Topic, Goal ).
  164debug_call( _Topic, _Goal ).
  165
  166debug_call_goal( Topic, Moal ) :-
  167    ( Moal = Mod:Goal -> true; Goal = Moal, Mod=user ),
  168    functor( Goal, Functor, Arity ),
  169    Extra is Arity + 2,
  170    current_predicate( Mod:Functor/Extra ),
  171    !,
  172    ( call(Mod:Goal,Mess,Args) ->
  173        debug( Topic, Mess, Args )
  174        ;
  175        true
  176    ).
  177debug_call_goal( _Topic, Goal ) :-
  178    ( call(Goal) -> true; true ).

 debug_chain(+TopicCond, +TopicDep)

 debug_chain(+TopicCond, +TopicDep, -TDprior)

If already debugging TopicCond, then also start debugging TopicDep ). TDprior is true if TopicDep was already debugging, else is false. Current implementation sets TDprior to true whenever Topic is not debugged, as it assumes that this value best suit independent fluctuation of TopicDep. Only in the case of debug_chain/2, TopicDep can be a list.

author

- nicos angelopoulos

version

- 0.1 2014/4/4

- 0.2 2016/11/1

See also

- debug_set/2

  194debug_chain( Topic, Then ) :-
  195    to_list( Then, Thens ),
  196    maplist( debug_chain(Topic), Thens, _Priors ).
  197
  198debug_chain( Topic, Then, Prior ) :-
  199    debugging_topic( Topic ),
  200    !,
  201    debugging_status( Then, Prior ),
  202    debug( Then ).
  203debug_chain( _Topic, _Then, true ). 
  204    % setting 3rd to true is a bit presumptious of its uses later on

 debug_message(+Topic, +Mess, +Args)

A wrap around debug/3 that calls it by constructing the term on-the-fly. So that lib(debug) does not create a record by inspecting the term (via expansion). Particularly useful in sending uninstantiated Topics.

author

- nicos angelopoulos

version

- 0.1 2016/11/1

*/

  220debug_message( Topic, Mess, Args ) :-
  221    Call =.. [debug,Topic,Mess,Args],
  222    call( Call ).

 debugging_topic(?Topic)

A wrap around debugging/1 that calls it by constructing the term on-the-fly. So that lib(debug) does not create a record by inspecting the term (via expansion). Particularly useful in sending uninstantiated Topics.

author

- nicos angelopoulos

version

- 0.1 2016/11/1

*/

  238debugging_topic( Topic ) :-
  239    Call =.. [debugging,Topic],
  240    call( Call ).

 debugging_status(+Topic, -Status)

Status == true iff debugging(Topic) succeeds. Else, it is false. Similar to debugging/2, but does not fail for undefined Topic.

 ?- debug( something ).
 true.
 ?- debugging_status( something, Some ).
 Some = true.
 ?- debugging_status( some_else, Else ).
 Else = false.

author

- nicos angelopoulos

version

- 0.1 2014/7/23

  257debugging_status( Topic, Status ) :-
  258    debugging_topic( Topic ),
  259    !,
  260    Status = true.
  261debugging_status( _Topic, false ).

 debug_set(+Prior, +Topic)

Reset Topic according to Prior: true sets Topic to on and false turns Topic off.

 ?- nodebug( chained ).
 true.
 ?- debug( testo ).
 Warning: testo: no matching debug topic (yet)
 true.
 ?- debug( chained, 'debugs chains 1', [] ).
 true.
 ?- debug_chain( testo, chained, Prior ).
 Prior = false.
 ?- debug( chained, 'debugs chains 2', [] ).
 % debugs chains 2
 true.
 ?- Prior = false, debug_set( Prior, chained ).
 Prior = false.
 ?- debug( chained, 'debugs chains 3', [] ).
 true

author

- nicos angelopoulos

version

- 0.1 2014/7/23

- 0.2 2016/8/22, Prior == true used to do nothing, now it turns topic on. also renmaed from debug_set/2.

See also

- debug_chain/3

  290debug_set( false, Topic ) :-
  291    nodebug( Topic ).
  292debug_set( true, Topic ) :-
  293    debug( Topic ).

 debug_topic(+Topic, +Opts, -Restore)

Start debugging Topic if options(debug(true),Opts), with Restore being instantiated to a term that can be used to restore the original debug state of Topic (see options_restore/2). If options(debug(false),Opts) then Topic is stopped from being debugged (Restore still holds the correct term for restoring debugging state for topic to precall status).

?- assert( ( on_t(I,Topic) :- (debugging(Topic) -> write(I-y(Topic)) ; write(I-n(Topic))), nl ) ).
?- T = options, debug(T), on_t(1,T), debug_topic(T,[debug(false)],R), on_t(2,T), debug_set(R,T), on_t(3,T).
1-y(options)
2-n(options)
3-y(options)
T = options,
R = true.

?- T = options, nodebug(T), on_t(1,T), debug_topic(T,[debug(true)],R), on_t(2,T), debug_set(R,T), on_t(3,T).
1-n(options)
2-y(options)
3-n(options)
T = options,
R = false.

author

- nicos angelopoulos

version

- 0.1 2016/8/22

*/

  324debug_topic( Topic, Opts, Restore ) :-
  325    memberchk( debug(Dbg), Opts ),
  326    Dbg == true,
  327    !,
  328    debug_topic_restore( Topic, Restore ),
  329    debug( Topic ).
  330debug_topic( Topic, _Opts, Restore )  :-        % becomes default under this implementation
  331    debug_topic_restore( Topic, Restore ),
  332    nodebug( Topic ).
  333
  334debug_topic_restore( Topic, Restore ) :- 
  335    debugging_topic( Topic ),
  336    !,
  337    Restore = true.
  338debug_topic_restore( _Topic, false ).

 debug_topic(+Flag, +Topic)

Start debugging Topic if Flag == true, and stop debugging if Flag == false.

 ?- debug_topic( true, example ).

author

- nicos angelopoulos

version

- 0.1 2014/12/10

- 0.2 2016/08/22, added nodebug/1 when Flag == false

See also

- options_append/4

  352debug_topic( true, Topic ) :-
  353    debug( Topic ).
  354debug_topic( false, Topic ) :-
  355    nodebug(Topic).

 debug_on(+Topic)

As debug/1, but do not print warning if topic is not known.

  361debug_on( Topic ) :-
  362    asserta( prolog_debug:debugging(Topic,true,[user_error])).

 debug_portray(+Topic, +Term)

Call portray_clause(Term) if we are debugging Topic.

author

- nicos angelopoulos

version

- 0.1

  371debug_portray( Topic, Term ) :-
  372    debugging_topic( Topic ),
  373    !,
  374    portray_clause( Term ).
  375debug_portray( _Topic, _Term ).

 debug_call(+Topic, +Goal, +Arg)

 debug_call(+Topic, +Goal, +Pfx, +Arg)

Automates often used debug calls. When Pfx is missing it is assumed to be ''. Predicate can also be used to call arbitrary Goal and then print a message after it has successfull completed. As of 1.2 it can also work as a replacement to debug/3. With 1.3 the debuc/3 shorthand was introduced.

When Goal is a known abbreviation, then Arg usually qualifies the output generated. When Goal is of the form call(Goal), Arg will be passed to debug(Topic,Mess,Arg).

Goal in:

call(Goal)

call Goal before printing debugging message debug( Topic, Mess, Args). (Goal is called in non-deterministic context).

dims

prints the dimensions of matrix, see mtx_dims/3

end

translates to finishing ~Arg or starting ~Topic if Arg == true

enum

print lists and deconstructed terms, where each item is prefixed with an index number

goal

anything that does n't match any of the above is retrived as call(Goal)

info

print using informational machinery (usually different/green colour, to debug's blue) term should Mess/Args in the debug/3 version

length

prints the lenghts of a bunch of lists. Args should be ListNames/Lists. uses non list ListNames if debuging the length of a single list, in which case message in the singular is used.

list

writes contents of list with header and footer. Arg should be of the form Hdr/Ftr/List, else it is translated as Hdr/''/List or ''/''/List. If Hdr or Ftr are '' then that part of the message is skipped

ns_sel

first argument is the item selected from second arg list (only reported if 2nd arg is not a singleton (ns)) accepts 2 optional args, 3rd is the token of what is selected (false for printing nothing on the subject, default) and 4th is whether to report if the 2nd argument is indeed a singleton (default: false)

ns_sel(true)

first argument is the item selected from second arg list. reports differently if 2nd arg is a singleton, but always does report

odir

output directory (Arg should exist and be a directory)

options

options used on call to predicate

pwd

message about current dir Location (=Arg), (if Arg == false, location is not shown)- see examples

read

reports reading from a file. Arg should be file specification suitable for locate/3. Either loc(File,Exts) or simply File in which case Exts = ''.

start

translates to starting ~Arg or starting ~Topic if Arg == true

task(Wch)

time of start/stop (Wch) of a task. Other values for Wch are allowed but printed as they come. Arg can be a term (as of Version 1.5).

term

simply spew the input term

var

reports variable name (arg(1)) and its current instantiation (arg(2))

wrote

reports the writting of output on a file. Arg should be file specification suitable for locate/3. Either loc(File,Exts) or simply File in which case Exts = ''.

 ?- debug( ex ).
 ?- debug_call( ex, length, '', list1/[x,y,z] ).
 % Length for list, list1: 3
  
 ?- debug_call( ex, length, 'some prefix', [list1,list2]/[[x,y,z],[a,b,c]] ).
 % some prefix lengths for lists, list1: 3, list2: 3
 
?- debug_call( ex, wrote, loc(file,csv) ).
% Could not locate wrote on file specified by: file, and extensions: csv
?- csv_write_file( 'file.csv', [] ).

?- debug_call( ex, wrote, loc(file,csv) ).
% Wrote on file: '/home/nicos/pl/lib/src/trace/file.csv'

?- debug_call( ex, task(stop), 'write on file' ).
% At 15:44:1 on 2nd of Jul 2014 finished task: write on file.
    
?- debug_call( ex, (length([a,b,c],L),write(len(L)),nl) ).
len(3)
L = 3.

?-  Etcs = [suv-17.09.26.txg,suv-17.09.21.txg], Etc = suv-17.09.26.txg,
    debug_call( suv, ns_sel, c(Etc,Etcs,'suv file',true) )
 Continuing with: suv file, as: suv-17.09.26.txg, from non singleton list: [suv-17.09.26.txg,suv-17.09.21.txg]

 ?- debuc( ex, pwd, here ).
 % Pwd at, here, is: '/Users/nicosangelopoulos/.local/share/swi-prolog/pack/Downloads/bio_db_repo-publish/bio_db_repo-20.09.14/data/hs/maps/hgnc/'
 true.
 
 ?- debuc( ex, pwd, false ).
 % Pwd: '/Users/nicosangelopoulos/.local/share/swi-prolog/pack/Downloads/bio_db_repo-publish/bio_db_repo-20.09.14/data/hs/maps/hgnc/'
 true.
 

At some point around SWI-Prolog 8, behaviour of debug/3 changed in being more strict about messages with no arguments. As of version 1.2 debug_call/3 can act as a replacement of debug/3 but with the old behaviour.

 ?- debug( ex, 'Messagging...', true ).
 Messagging...
 [[ EXCEPTION while printing message 'Messagging...'
       with arguments user:true:
       raised: format('too many arguments')
    ]]
 
 true.
 
 ?- debug_call( ex, 'Messagging...', true ).
 % Messagging...
 true.

author

- nicos angelopoulos

version

- 0.1 2014/03/27

- 0.2 2014/04/24 added wrote

- 0.3 2014/07/2 added task

- 0.4 2014/09/22 renamed from debug_call/3

- 0.5 2014/??/?? added ns_sel

- 1.1 2018/03/20 prefer +2 arity in debug_call/2

- 1.2 2020/03/07 now can be used as a replacement for debug/3 (but with old 3rd arg behaviour, allowing eg 'true').

- 1.3 2020/09/14 added canned calls info and enum, debuc/2,3,4

See also

- debuc/3 (shorthand for debug_call/3).

  501debug_call( Topic, Goal, Args ) :-
  502    debug_call( Topic, Goal, '', Args ).
  503
  504debug_call( Topic, Goal, Pfx, Args ) :-
  505    debugging_topic( Topic ),
  506    !,
  507    debugging_call( Topic, Goal, Pfx, Args ).
  508debug_call( _Topic, _Goal, _Mess, _Args ).
  509
  510debugging_call( Topic, Goal, Mess, Args ) :-
  511    debug_call_topic( Goal, Mess, Args, Topic ),
  512    !.
  513debugging_call( Topic, call(Goal), Mess, Args ) :-
  514    !,
  515    call( Goal ),
  516    debug_message( Topic, Mess, Args ).
  517debugging_call( Topic, Goal, Mess, Args ) :-
  518    compound( Goal ),
  519    call( Goal ),
  520    !,
  521    debug_message( Topic, Mess, Args ).
  522% 20.03.07: this makes debug_call/3 a replacement for debug/3...
  523debugging_call( Topic, Mess, '', DbgCallArgs ) :-
  524    % as of SWI-Prolog 8.?.? there is an error thrown when true is used instead of [] as 3rd arg of debug/3
  525    atomic( Mess ),
  526    !,
  527    ( DbgCallArgs == true -> Args = []; DbgCallArgs = Args ),
  528    debug( Topic, Mess, Args ).
  529debugging_call( Topic, Goal, Mess, Args ) :-
  530    Called = debug_call(Topic,Goal,Mess,Args),
  531    message_report( 'failure ignored on: ~w', Called, warning ).

 debug_consec(+Topic, +Mess, +Args)

 debug_consec(+Topic, +Clrs, +Mess, +Args)

Alternate the colours of printing messages on Topic, from those in Clrs. When missing these are [blue,magenta]. As of v0.2 Clrs can be a single colour.

 ?- debug( dbg ).
 ?- debug_consec( dbg, 'what:~w', when ).
 % what: when            <- in blue

 ?- debug_consec( dbg, 'what:~w', when ).
 % what: when            <- in magenta

 ?- debug_consec( dbg, [blue,green], 'what:~w', when ).
 % what: when            <- in blue

 ?- debug_consec( dbg, [blue,green], 'what:~w', when ).
 % what: when            <- in green
 

Version 0.2

 ?- debug_consec( dbg, magenta, 'what:~w', when ).
 % what: when            <- in magenta

author

- nicos angelopoulos

version

- 0.2 2019/12/29

- 0.1 2014/7/24

  566debug_consec( Topic, Mess, Args ) :-
  567    Clrs = [blue,magenta],
  568    debug_consec( Topic, Clrs, Mess, Args ).
  569
  570debug_consec( Topic, ClrS, Mess, Args ) :-
  571    debugging_topic( Topic ),
  572    !,
  573    ( is_list(ClrS) -> Clrs = ClrS; Clrs = [ClrS] ),
  574    debug_consec_topic( Topic, Clrs, Mess, Args ).
  575debug_consec( _Topic, _Clrs, _Mess, _Args ).
  576
  577debug_consec_topic( Topic, Clrs, Mess, Args ) :-
  578    with_output_to( atom(Topicat), write_term(Topic,[]) ),
  579    ( nb_current(Topicat,Value) -> true; Value = 1 ),
  580    ( nth1(Value, Clrs, Clr) -> true; Clrs = [Clr|_] ),
  581    debug_consec_color( Topic, Clr, Mess, Args ),
  582    length( Clrs, Len ),
  583    ( Value < Len -> Next is Value + 1; Next is 1 ),
  584    nb_setval( Topicat, Next ).
  585
  586debug_consec_color( Topic, Clr, Mess, Args ) :-
  587    user:message_property( debug(_), color(Attrs) ),
  588    !,
  589    retractall( debug_call_message_property(debug(_),color(_)) ),
  590    assert( debug_call_message_property(debug(_),color(fg(Clr))) ),
  591    debug_message( Topic, Mess, Args ),
  592    retractall( debug_call_message_property(debug(_),color(_)) ),
  593    assert( debug_call_message_property(debug(_),color(Attrs)) ).
  594debug_consec_color( Topic, Clr, Mess, Args ) :-
  595    assert( debug_call_message_property(debug(_),color(fg(Clr))) ),
  596    debug_message( Topic, Mess, Args ),
  597    retractall( debug_call_message_property(debug(_),color(_)) ).
  598
  599debug_call_topic( info, Pfx, Arg, _Topic ) :-
  600    ( (\+ var(Arg),Arg = Mess/Args) ->
  601        true
  602        ;
  603        % fixme: not sure what to do here ?
  604        Mess = Arg,
  605        Args = []
  606    ),
  607    % lib_message_report( Format, Args, Kind ) :-
  608    debug_message_prefixed( Pfx, Mess, Prefixed ),
  609	phrase('$messages':translate_message(debug(Prefixed,Args)), Lines),
  610	print_message_lines(current_output, kind(informational), Lines).
  611
  612debug_call_topic( dims, Pfx, NamesPrv/MtxsPrv, Topic ) :-
  613    ( is_list(NamesPrv) -> Names=NamesPrv, MtxsPrv=Mtxs, With = 'Dimensions for matrices, '
  614                           ; [NamesPrv] = Names, [MtxsPrv]=Mtxs, With = 'Dimensions for matrix, ' 
  615    ),
  616    debug_message_prefixed( Pfx, With, Prefixed ),
  617    maplist( debug_mtx_dims, Mtxs, NRows, NCols ),
  618    findall( PartM, (member(_,Names),PartM=' (~w) nR: ~d, nC: ~d.'), MParts ),
  619    atomic_list_concat( MParts, '', Right ),
  620    findall( [Name,NRow,NCol], (nth1(N,Names,Name),nth1(N,NRows,NRow),nth1(N,NCols,NCol)), NNest ),
  621    flatten( NNest, Vars ),
  622    atom_concat( Prefixed, Right, Message ),
  623    debug_message( Topic, Message, Vars ). % do the messaging !
  624debug_call_topic( enum, Pfx, InArg, Topic ) :-
  625    ground( InArg ),
  626    ( InArg = Left/Term -> true; Left = unnamed, Term = InArg ),
  627    ( is_list(Term) ->
  628        length( Term, Len ),
  629        number_codes( Len, LenCs ),
  630        length( LenCs, SpcLen ),
  631        debug_call_topic_list_delim( Left, Topic, Pfx, 'Starting enumeration of list: ~w' ),
  632        debug_call_topic_enum( Term, 1, SpcLen, Topic ),
  633        debug_call_topic_list_delim( Left, Topic, Pfx, 'Ended enumeration of list: ~w' )
  634        ;
  635        Term =.. Args,
  636        length( Args, Len ),
  637        number_codes( Len, LenCs ),
  638        length( LenCs, SpcLen ),
  639        debug_call_topic_list_delim( Left, Topic, Pfx, 'Starting enumeration of list: ~w' ),
  640        debug_call_topic_enum( Args, 1, SpcLen, Topic ),
  641        debug_call_topic_list_delim( Left, Topic, Pfx, 'Ended enumeration of list: ~w' )
  642    ).
  643debug_call_topic( length, Pfx, NamesPrv/ListsPrv, Topic ) :-
  644                            % add version without names
  645    ( is_list(NamesPrv) -> Names=NamesPrv, ListsPrv=Lists, With = 'Lengths for lists, '
  646                           ; [NamesPrv] = Names, [ListsPrv]=Lists, With = 'Length for list, ' 
  647    ),
  648    debug_message_prefixed( Pfx, With, Prefixed ),
  649    maplist( length, Lists, Lengths ),
  650    findall( ['~w: ~w',', '], member(_,Lengths), WsNest ),
  651    flatten( WsNest, WsL ),
  652    once( append(WsLComma,[_],WsL) ),
  653    append( WsLComma, ['.'], WsLDot ),
  654    atomic_list_concat( WsLDot, '', Right ),
  655    atom_concat( Prefixed, Right, Message ),
  656    findall( [Name,Length], (nth1(N,Names,Name),nth1(N,Lengths,Length)), NLNest ),
  657    flatten( NLNest, NLs ),
  658    debug_message( Topic, Message, NLs ). % do the messaging
  659debug_call_topic( list, _Pfx, InArg, Topic ) :-
  660    ground( InArg ),
  661    ( InArg = Left/List -> 
  662        ( Left = Hdr/Ftr -> true ; Hdr = Left, Ftr = '' )
  663        ;
  664        List = InArg, Hdr = '', Ftr = ''
  665    ),
  666    debug_call_topic_list_delim( Hdr, Topic, Pfx, 'Starting listing of list: ~w' ),
  667    maplist( debug_message(Topic,'~w'), List ),
  668    debug_call_topic_list_delim( Ftr, Topic, Pfx, 'Ended listing of list: ~w' ).
  669debug_call_topic( odir, Pfx, Odir, Topic ) :-
  670    ( exists_directory(Odir) ->
  671        Mess = 'Ouput in directory: ~w'
  672        ;
  673        Mess = 'Output (claimed) in (non-existing) directory: ~w'
  674    ),
  675    debug_message_prefixed( Pfx, Mess, Prefixed ),
  676    debug_message( Topic, Prefixed, [Odir] ).
  677debug_call_topic( options, _Pfx, InArg, Topic ) :-
  678    ( InArg = Left/Opts -> true; Left = unnamed, Opts = InArg ),
  679    debug( Topic, 'Options in predicate: ~w, are: ~w', [Left,Opts] ).
  680debug_call_topic( term, Pfx, DbgTerm, Topic ) :-
  681    Mess = '~w',
  682    debug_message_prefixed( Pfx, Mess, Prefixed ),
  683    debug_message( Topic, Prefixed, [DbgTerm] ).
  684debug_call_topic( var, Pfx, DbgTerm, Topic ) :-
  685    arg( 1, DbgTerm, Var ),
  686    arg( 2, DbgTerm, Val ),
  687    Mess = 'Variable: ~a, value: ~w',
  688    debug_message_prefixed( Pfx, Mess, Prefixed ),
  689    debug_message( Topic, Prefixed, [Var,Val] ).
  690debug_call_topic( wrote, Pfx, ForLoc, Topic ) :-
  691    ( ForLoc = loc(Spec,Ext) -> true; Spec=ForLoc, Ext = '' ),
  692    catch( locate(Spec,Ext,Loc), Excp, true ),
  693    MessW = 'Wrote on file: ~p',
  694    debug_call_location_exception_message( Excp, Loc, MessW, Mess, Args ),
  695    debug_message_prefixed( Pfx, Mess, Prefixed ),
  696    debug_message( Topic, Prefixed, Args ).
  697debug_call_topic( read, Pfx, ForLoc, Topic ) :-
  698    ( ForLoc = loc(Spec,Ext) -> true; Spec=ForLoc, Ext = '' ),
  699    catch( locate(Spec,Ext,Loc), Excp, true ),
  700    MessW = 'Read from file: ~p',
  701    debug_call_location_exception_message( Excp, Loc, MessW, Mess, Args ),
  702    debug_message_prefixed( Pfx, Mess, Prefixed ),
  703    debug_message( Topic, Prefixed, Args ).
  704debug_call_topic( task(Whc), Pfx, Task, Topic ) :-
  705    datime_readable( Readable ),
  706    debug_call_topic_time_which_readable( Whc, Whcable ),
  707    atomic_list_concat( [Readable,' ',Whcable,' task: ~w.'], Mess ),
  708    debug_message_prefixed( Pfx, Mess, Prefixed ),
  709    debug_message( Topic, Prefixed, [Task] ).
  710debug_call_topic( start, Pfx, Arg, Topic ) :-
  711    Mess = 'Starting: ~w',
  712    debug_message_prefixed( Pfx, Mess, Prefixed ),
  713    ( Arg == true -> Rep = Topic; Rep = Arg ),
  714    debug_message( Topic, Prefixed, [Rep] ).
  715debug_call_topic( end, Pfx, Arg, Topic ) :-
  716    Mess = 'Finished: ~w',
  717    debug_message_prefixed( Pfx, Mess, Prefixed ),
  718    ( Arg == true -> Rep = Topic; Rep = Arg ),
  719    debug_message( Topic, Prefixed, [Rep] ).
  720debug_call_topic( pwd, Pfx, Stage, Topic ) :-
  721    working_directory( Pwd, Pwd ),
  722    ( Stage == false -> 
  723        Mess = 'Pwd: ~p', Args = [Pwd]
  724        ;
  725        Mess = 'Pwd at, ~w, is: ~p', Args = [Stage,Pwd]
  726    ),
  727    debug_message_prefixed( Pfx, Mess, Prefixed ),
  728    debug_message( Topic, Prefixed, Args ).
  729debug_call_topic( ns_sel, Pfx, Term, Topic ) :-
  730    % ( Term = [Fst,Sec] -> true; arg(1,Term,Fst),arg(2,Term,Sec) ),
  731    arg( 1, Term, Fst ), 
  732    arg( 2, Term, Sec ),
  733    functor( Term, _Tname, Arity ),
  734    ( Sec == [] -> 
  735        true % fixme: it will make more sense to throw an error if Sec = []
  736        ;
  737        ( Sec = [_Single] ->
  738            ( (Arity>3,arg(4,Term,true)) ->
  739                ( (Arity>2,\+ arg(3,Term,false)) ->
  740                    arg(3,Term,Trd),
  741                    Mess= 'Continuing with: ~w as: ~w, (only match).', MArgs = [Trd,Fst]
  742                    ;
  743                    Mess= 'Continuing with only match: ~w.', MArgs = [Fst,Sec]
  744                )
  745                ;
  746                Mess = 'Continuing: ~w, from non singleton list: ~w', MArgs = [Fst,Sec]
  747            )
  748            ;
  749            ( (Arity>2,\+ arg(3,Term,false)) ->
  750                arg(3,Term,Trd),
  751                Mess = 'Continuing with: ~w, as: ~w, from non singleton list: ~w', MArgs = [Trd,Fst,Sec]
  752                ;
  753                Mess = 'Continuing: ~w, from non singleton list: ~w', MArgs = [Fst,Sec]
  754            )
  755        ),
  756        debug_message_prefixed( Pfx, Mess, Prefixed ),
  757        debug_message( Topic, Prefixed, MArgs )
  758    ).
  759
  760debug_call_topic_enum( [], _I, _Len, _Topic ).
  761debug_call_topic_enum( [H|T], I, Len, Topic ) :-
  762    number_codes( I, ICs ),
  763    length( ICs, ICsLen ),
  764    PadLen is Len - ICsLen,
  765    findall( ' ', between(1,PadLen,_), Spcs ),
  766    atomic_list_concat( Spcs, '', Pad ),
  767    atomic_list_concat( [Pad,'~d.~w'], '', Mess ),
  768    debug_message( Topic, Mess, [I,H] ),
  769    J is I + 1,
  770    debug_call_topic_enum( T, J, Len, Topic ).
  771
  772debug_call_topic_list_delim( '', _Topic, _Pfx, _Mess ).
  773debug_call_topic_list_delim( ListName, Topic, Pfx, Mess ) :-
  774    debug_message_prefixed( Pfx, Mess, Prefixed ),
  775    debug_message( Topic, Prefixed, [ListName] ).
  776
  777debug_call_topic_time_which_readable( Wch, Wchable ) :-
  778    debug_call_topic_time_which_readable_known( Wch, Wchable ),
  779    !.
  780debug_call_topic_time_which_readable( Wch, Wch ).
  781
  782debug_call_topic_time_which_readable_known( start, starting ).
  783debug_call_topic_time_which_readable_known( finish, finished ).
  784
  785debug_call_location_exception_message( Var, Loc, MessI, MessO, Args ) :-
  786    var(Var),
  787    !,
  788    MessI = MessO,
  789    Args = Loc.
  790debug_call_location_exception_message( locate(cannot_locate(Spec,Ext)), _Loc, _MessI, Mess, Args ) :-
  791    Mess = 'Could not locate file specified by: ~w, and extensions: ~w',
  792    Args = [Spec,Ext].
  793debug_call_location_exception_message( Error, _Loc, _MessI, _Mess, _Args ) :-
  794    % fixme:
  795    throw( debug_call_caught(Error) ).
  796
  797debug_mtx_dims( [], 0, 0 ) :-
  798    !.
  799debug_mtx_dims( Rows, NRows, NCols ) :-
  800    length( Rows, NRows ),
  801    Rows = [Hdr|_],
  802    ( is_list(Hdr) -> length(Hdr,NCols); functor(Hdr,_,NCols) ).
  803
  804debug_message_prefixed( '', Standard, Standard ) :- !.
  805debug_message_prefixed( Pfx, Standard, Prefixed ) :-
  806    sub_atom( Standard, 0, 1, Aft, Fst ),
  807    downcase_atom( Fst, Low ),
  808    sub_atom( Standard, 1, Aft, 0, Right ),
  809    atomic_list_concat( [Pfx,' ',Low,Right], Prefixed )