/* Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@vu.nl
WWW: http://www.swi-prolog.org
Copyright (c) 2010-2023, VU University Amsterdam
CWI, Amsterdam
SWI-Prolog Solutions b.v.
All rights reserved.
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modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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*/
:- module(ansi_term,
[ ansi_format/3, % +Attr, +Format, +Args
ansi_get_color/2, % +Which, -rgb(R,G,B)
ansi_hyperlink/2, % +Stream,+Location
ansi_hyperlink/3 % +Stream,+URL,+Label
]).
:- autoload(library(error), [domain_error/2, must_be/2, instantiation_error/1]).
:- autoload(library(lists), [append/3]).
:- autoload(library(uri), [uri_file_name/2]).
:- if(exists_source(library(time))).
:- autoload(library(time), [call_with_time_limit/2]).
:- endif.
/** <module> Print decorated text to ANSI consoles
This library allows for exploiting the color and attribute facilities of
most modern terminals using ANSI escape sequences. This library provides
the following:
- ansi_format/3 allows writing messages to the terminal with ansi
attributes.
- It defines the hook prolog:message_line_element/2, which provides
ansi attributes and hyperlinks for print_message/2.
The behavior of this library is controlled by two Prolog flags:
- `color_term`
When `true`, activate the color output for this library. Otherwise
simply call format/3.
- `hyperlink_term`
Emit terminal hyperlinks for url(Location) and url(URL, Label)
elements of Prolog messages.
@see http://en.wikipedia.org/wiki/ANSI_escape_code
*/
:- multifile
prolog:console_color/2, % +Term, -AnsiAttrs
supports_get_color/0,
hyperlink/2. % +Stream, +Spec
color_term_flag_default(true) :-
stream_property(user_input, tty(true)),
stream_property(user_error, tty(true)),
stream_property(user_output, tty(true)),
\+ getenv('TERM', dumb),
!.
color_term_flag_default(false).
init_color_term_flag :-
color_term_flag_default(Default),
create_prolog_flag(color_term, Default,
[ type(boolean),
keep(true)
]),
create_prolog_flag(hyperlink_term, false,
[ type(boolean),
keep(true)
]).
:- init_color_term_flag.
:- meta_predicate
keep_line_pos(+, 0).
:- multifile
user:message_property/2.
%! ansi_format(+ClassOrAttributes, +Format, +Args) is det.
%
% Format text with ANSI attributes. This predicate behaves as
% format/2 using Format and Args, but if the =current_output= is a
% terminal, it adds ANSI escape sequences according to Attributes.
% For example, to print a text in bold cyan, do
%
% ==
% ?- ansi_format([bold,fg(cyan)], 'Hello ~w', [world]).
% ==
%
% Attributes is either a single attribute, a list thereof or a term
% that is mapped to concrete attributes based on the current theme
% (see prolog:console_color/2). The attribute names are derived from
% the ANSI specification. See the source for sgr_code/2 for details.
% Some commonly used attributes are:
%
% - bold
% - underline
% - fg(Color), bg(Color), hfg(Color), hbg(Color)
% For fg(Color) and bg(Color), the colour name can be '#RGB' or
% '#RRGGBB'
% - fg8(Spec), bg8(Spec)
% 8-bit color specification. Spec is a colour name, h(Color)
% or an integer 0..255.
% - fg(R,G,B), bg(R,G,B)
% 24-bit (direct color) specification. The components are
% integers in the range 0..255.
%
% Defined color constants are below. =default= can be used to
% access the default color of the terminal.
%
% - black, red, green, yellow, blue, magenta, cyan, white
%
% ANSI sequences are sent if and only if
%
% - The =current_output= has the property tty(true) (see
% stream_property/2).
% - The Prolog flag =color_term= is =true=.
ansi_format(Attr, Format, Args) :-
ansi_format(current_output, Attr, Format, Args).
ansi_format(Stream, Class, Format, Args) :-
stream_property(Stream, tty(true)),
current_prolog_flag(color_term, true),
!,
class_attrs(Class, Attr),
phrase(sgr_codes_ex(Attr), Codes),
atomic_list_concat(Codes, ;, Code),
with_output_to(
Stream,
( keep_line_pos(current_output, format('\e[~wm', [Code])),
format(Format, Args),
keep_line_pos(current_output, format('\e[0m'))
)
),
flush_output.
ansi_format(Stream, _Attr, Format, Args) :-
format(Stream, Format, Args).
sgr_codes_ex(X) -->
{ var(X),
!,
instantiation_error(X)
}.
sgr_codes_ex([]) -->
!.
sgr_codes_ex([H|T]) -->
!,
sgr_codes_ex(H),
sgr_codes_ex(T).
sgr_codes_ex(Attr) -->
( { sgr_code(Attr, Code) }
-> ( { is_list(Code) }
-> list(Code)
; [Code]
)
; { domain_error(sgr_code, Attr) }
).
list([]) --> [].
list([H|T]) --> [H], list(T).
%! sgr_code(+Name, -Code)
%
% True when code is the Select Graphic Rendition code for Name.
% The defined names are given below. Note that most terminals only
% implement this partially.
%
% | reset | all attributes off |
% | bold | |
% | faint | |
% | italic | |
% | underline | |
% | blink(slow) | |
% | blink(rapid) | |
% | negative | |
% | conceal | |
% | crossed_out | |
% | font(primary) | |
% | font(N) | Alternate font (1..8) |
% | fraktur | |
% | underline(double) | |
% | intensity(normal) | |
% | fg(Name) | Color name |
% | bg(Name) | Color name |
% | framed | |
% | encircled | |
% | overlined | |
% | ideogram(underline) | |
% | right_side_line | |
% | ideogram(underline(double)) | |
% | right_side_line(double) | |
% | ideogram(overlined) | |
% | left_side_line | |
% | ideogram(stress_marking) | |
% | -Off | Switch attributes off |
% | hfg(Name) | Color name |
% | hbg(Name) | Color name |
%
% @see http://en.wikipedia.org/wiki/ANSI_escape_code
sgr_code(reset, 0).
sgr_code(bold, 1).
sgr_code(faint, 2).
sgr_code(italic, 3).
sgr_code(underline, 4).
sgr_code(blink(slow), 5).
sgr_code(blink(rapid), 6).
sgr_code(negative, 7).
sgr_code(conceal, 8).
sgr_code(crossed_out, 9).
sgr_code(font(primary), 10) :- !.
sgr_code(font(N), C) :-
C is 10+N.
sgr_code(fraktur, 20).
sgr_code(underline(double), 21).
sgr_code(intensity(normal), 22).
sgr_code(fg(Name), C) :-
( ansi_color(Name, N)
-> C is N+30
; rgb(Name, R, G, B)
-> sgr_code(fg(R,G,B), C)
).
sgr_code(bg(Name), C) :-
!,
( ansi_color(Name, N)
-> C is N+40
; rgb(Name, R, G, B)
-> sgr_code(bg(R,G,B), C)
).
sgr_code(framed, 51).
sgr_code(encircled, 52).
sgr_code(overlined, 53).
sgr_code(ideogram(underline), 60).
sgr_code(right_side_line, 60).
sgr_code(ideogram(underline(double)), 61).
sgr_code(right_side_line(double), 61).
sgr_code(ideogram(overlined), 62).
sgr_code(left_side_line, 62).
sgr_code(ideogram(stress_marking), 64).
sgr_code(-X, Code) :-
off_code(X, Code).
sgr_code(hfg(Name), C) :-
ansi_color(Name, N),
C is N+90.
sgr_code(hbg(Name), C) :-
!,
ansi_color(Name, N),
C is N+100.
sgr_code(fg8(Name), [38,5,N]) :-
ansi_color8(Name, N).
sgr_code(bg8(Name), [48,5,N]) :-
ansi_color8(Name, N).
sgr_code(fg(R,G,B), [38,2,R,G,B]) :-
between(0, 255, R),
between(0, 255, G),
between(0, 255, B).
sgr_code(bg(R,G,B), [48,2,R,G,B]) :-
between(0, 255, R),
between(0, 255, G),
between(0, 255, B).
off_code(italic_and_franktur, 23).
off_code(underline, 24).
off_code(blink, 25).
off_code(negative, 27).
off_code(conceal, 28).
off_code(crossed_out, 29).
off_code(framed, 54).
off_code(overlined, 55).
ansi_color8(h(Name), N) :-
!,
ansi_color(Name, N0),
N is N0+8.
ansi_color8(Name, N) :-
atom(Name),
!,
ansi_color(Name, N).
ansi_color8(N, N) :-
between(0, 255, N).
ansi_color(black, 0).
ansi_color(red, 1).
ansi_color(green, 2).
ansi_color(yellow, 3).
ansi_color(blue, 4).
ansi_color(magenta, 5).
ansi_color(cyan, 6).
ansi_color(white, 7).
ansi_color(default, 9).
rgb(Name, R, G, B) :-
atom_codes(Name, [0'#,R1,R2,G1,G2,B1,B2]),
hex_color(R1,R2,R),
hex_color(G1,G2,G),
hex_color(B1,B2,B).
rgb(Name, R, G, B) :-
atom_codes(Name, [0'#,R1,G1,B1]),
hex_color(R1,R),
hex_color(G1,G),
hex_color(B1,B).
hex_color(D1,D2,V) :-
code_type(D1, xdigit(V1)),
code_type(D2, xdigit(V2)),
V is 16*V1+V2.
hex_color(D1,V) :-
code_type(D1, xdigit(V1)),
V is 16*V1+V1.
%! prolog:console_color(+Term, -AnsiAttributes) is semidet.
%
% Hook that allows for mapping abstract terms to concrete ANSI
% attributes. This hook is used by _theme_ files to adjust the
% rendering based on user preferences and context. Defaults are
% defined in the file `boot/messages.pl`.
%
% @see library(theme/dark) for an example implementation and the Term
% values used by the system messages.
/*******************************
* HOOK *
*******************************/
%! prolog:message_line_element(+Stream, +Term) is semidet.
%
% Hook implementation that deals with ansi(+Attr, +Fmt, +Args) in
% message specifications.
prolog:message_line_element(S, ansi(Class, Fmt, Args)) :-
class_attrs(Class, Attr),
ansi_format(S, Attr, Fmt, Args).
prolog:message_line_element(S, ansi(Class, Fmt, Args, Ctx)) :-
class_attrs(Class, Attr),
ansi_format(S, Attr, Fmt, Args),
( nonvar(Ctx),
Ctx = ansi(_, RI-RA)
-> keep_line_pos(S, format(S, RI, RA))
; true
).
prolog:message_line_element(S, url(Location)) :-
ansi_hyperlink(S, Location).
prolog:message_line_element(S, url(URL, Label)) :-
ansi_hyperlink(S, URL, Label).
prolog:message_line_element(S, begin(Level, Ctx)) :-
level_attrs(Level, Attr),
stream_property(S, tty(true)),
current_prolog_flag(color_term, true),
!,
( is_list(Attr)
-> sgr_codes(Attr, Codes),
atomic_list_concat(Codes, ;, Code)
; sgr_code(Attr, Code)
),
keep_line_pos(S, format(S, '\e[~wm', [Code])),
Ctx = ansi('\e[0m', '\e[0m\e[~wm'-[Code]).
prolog:message_line_element(S, end(Ctx)) :-
nonvar(Ctx),
Ctx = ansi(Reset, _),
keep_line_pos(S, write(S, Reset)).
sgr_codes([], []).
sgr_codes([H0|T0], [H|T]) :-
sgr_code(H0, H),
sgr_codes(T0, T).
level_attrs(Level, Attrs) :-
user:message_property(Level, color(Attrs)),
!.
level_attrs(Level, Attrs) :-
class_attrs(message(Level), Attrs).
class_attrs(Class, Attrs) :-
user:message_property(Class, color(Attrs)),
!.
class_attrs(Class, Attrs) :-
prolog:console_color(Class, Attrs),
!.
class_attrs(Class, Attrs) :-
'$messages':default_theme(Class, Attrs),
!.
class_attrs(Attrs, Attrs).
%! ansi_hyperlink(+Stream, +Location) is det.
%! ansi_hyperlink(+Stream, +URL, +Label) is det.
%
% Create a hyperlink for a terminal emulator. The file is fairly easy,
% but getting the line and column across is not as there seems to be
% no established standard. The current implementation emits, i.e.,
% inserting a capital ``L`` before the line.
%
% ``file://AbsFileName[#LLine[:Column]]``
%
% @see https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
ansi_hyperlink(Stream, Location) :-
hyperlink(Stream, url(Location)),
!.
ansi_hyperlink(Stream, Location) :-
location_label(Location, Label),
ansi_hyperlink(Stream, Location, Label).
location_label(File:Line:Column, Label) =>
format(string(Label), '~w:~w:~w', [File,Line,Column]).
location_label(File:Line, Label) =>
format(string(Label), '~w:~w', [File,Line]).
location_label(File, Label) =>
format(string(Label), '~w', [File]).
ansi_hyperlink(Stream, Location, Label) :-
hyperlink(Stream, url(Location, Label)),
!.
ansi_hyperlink(Stream, File:Line:Column, Label) :-
!,
( url_file_name(URI, File)
-> format(Stream, '\e]8;;~w#~d:~d\e\\~w\e]8;;\e\\',
[ URI, Line, Column, Label ])
; format(Stream, '~w', [Label])
).
ansi_hyperlink(Stream, File:Line, Label) :-
!,
( url_file_name(URI, File)
-> format(Stream, '\e]8;;~w#~w\e\\~w\e]8;;\e\\',
[ URI, Line, Label ])
; format(Stream, '~w:~w', [File, Line])
).
ansi_hyperlink(Stream, File, Label) :-
( url_file_name(URI, File)
-> format(Stream, '\e]8;;~w\e\\~w\e]8;;\e\\',
[ URI, Label ])
; format(Stream, '~w', [File])
).
%! hyperlink(+Stream, +Spec) is semidet.
%
% Multifile hook that may be used to redefine ansi_hyperlink/2,3. If
% this predicate succeeds the system assumes the link has been written
% to Stream.
%
% @arg Spec is either url(Location) or url(URL, Label). See
% ansi_hyperlink/2,3 for details.
:- dynamic has_lib_uri/1 as volatile.
url_file_name(URL, File) :-
current_prolog_flag(hyperlink_term, true),
( has_lib_uri(true)
-> uri_file_name(URL, File)
; exists_source(library(uri))
-> use_module(library(uri), [uri_file_name/2]),
uri_file_name(URL, File),
asserta(has_lib_uri(true))
; asserta(has_lib_uri(false)),
fail
).
%! keep_line_pos(+Stream, :Goal)
%
% Run goal without changing the position information on Stream. This
% is used to avoid that the exchange of ANSI sequences modifies the
% notion of, notably, the `line_pos` notion.
keep_line_pos(S, G) :-
stream_property(S, position(Pos)),
!,
setup_call_cleanup(
stream_position_data(line_position, Pos, LPos),
G,
set_stream(S, line_position(LPos))).
keep_line_pos(_, G) :-
call(G).
%! ansi_get_color(+Which, -RGB) is semidet.
%
% Obtain the RGB color for an ANSI color parameter. Which is either a
% color alias or an integer ANSI color id. Defined aliases are
% `foreground` and `background`. This predicate sends a request to the
% console (`user_output`) and reads the reply. This assumes an `xterm`
% compatible terminal.
%
% @arg RGB is a term rgb(Red,Green,Blue). The color components are
% integers in the range 0..65535.
:- if(current_predicate(call_with_time_limit/2)).
ansi_get_color(Which0, RGB) :-
stream_property(user_input, tty(true)),
stream_property(user_output, tty(true)),
stream_property(user_error, tty(true)),
supports_get_color,
( color_alias(Which0, Which)
-> true
; must_be(between(0,15),Which0)
-> Which = Which0
),
catch(keep_line_pos(user_output,
ansi_get_color_(Which, RGB)),
time_limit_exceeded,
no_xterm).
supports_get_color :-
getenv('TERM', Term),
sub_atom(Term, 0, _, _, xterm),
\+ getenv('TERM_PROGRAM', 'Apple_Terminal').
color_alias(foreground, 10).
color_alias(background, 11).
ansi_get_color_(Which, rgb(R,G,B)) :-
format(codes(Id), '~w', [Which]),
hex4(RH),
hex4(GH),
hex4(BH),
phrase(("\e]", Id, ";rgb:", RH, "/", GH, "/", BH, "\a"), Pattern),
call_with_time_limit(0.05,
with_tty_raw(exchange_pattern(Which, Pattern))),
!,
hex_val(RH, R),
hex_val(GH, G),
hex_val(BH, B).
no_xterm :-
print_message(warning, ansi(no_xterm_get_colour)),
fail.
hex4([_,_,_,_]).
hex_val([D1,D2,D3,D4], V) :-
code_type(D1, xdigit(V1)),
code_type(D2, xdigit(V2)),
code_type(D3, xdigit(V3)),
code_type(D4, xdigit(V4)),
V is (V1<<12)+(V2<<8)+(V3<<4)+V4.
exchange_pattern(Which, Pattern) :-
format(user_output, '\e]~w;?\a', [Which]),
flush_output(user_output),
read_pattern(user_input, Pattern, []).
read_pattern(From, Pattern, NotMatched0) :-
copy_term(Pattern, TryPattern),
append(Skip, Rest, NotMatched0),
append(Rest, RestPattern, TryPattern),
!,
echo(Skip),
try_read_pattern(From, RestPattern, NotMatched, Done),
( Done == true
-> Pattern = TryPattern
; read_pattern(From, Pattern, NotMatched)
).
%! try_read_pattern(+From, +Pattern, -NotMatched)
try_read_pattern(_, [], [], true) :-
!.
try_read_pattern(From, [H|T], [C|RT], Done) :-
get_code(C),
( C = H
-> try_read_pattern(From, T, RT, Done)
; RT = [],
Done = false
).
echo([]).
echo([H|T]) :-
put_code(user_output, H),
echo(T).
:- else.
ansi_get_color(_Which0, _RGB) :-
fail.
:- endif.
:- multifile prolog:message//1.
prolog:message(ansi(no_xterm_get_colour)) -->
[ 'Terminal claims to be xterm compatible,'-[], nl,
'but does not report colour info'-[]
].