/* Part of SWISH
Author: Jan Wielemaker
E-mail: J.Wielemaker@cs.vu.nl
WWW: http://www.swi-prolog.org
Copyright (C): 2018, VU University Amsterdam
CWI Amsterdam
All rights reserved.
Redistribution and use in source and binary forms, with or without
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
distribution.
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
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
:- module(md_eval,
[ swish_provides/1 % ?Term
]).
:- use_module(library(modules)).
:- use_module(library(apply)).
:- use_module(library(lists)).
:- use_module(library(debug)).
:- use_module(library(option)).
:- use_module(library(occurs)).
:- use_module(library(settings)).
:- use_module(library(error)).
:- use_module(library(pldoc/doc_wiki)).
:- use_module(library(dcg/basics)).
:- use_module(library(time)).
:- use_module(config).
:- multifile
provides/1. % ?Term
:- setting(time_limit, number, 10,
"Timit limit for evaluating a ```{eval} cell").
/** <module> Provide evaluable markdown
This module adds evaluable sections to markdown cells in SWISH
notebooks. Such cells are written as
==
```{eval}
<Prolog code>
```
==
*/
%! eval_dom(+DOM0, -DOM, +Options) is semidet.
%
% This predicate post-processes the wiki DOM result if the DOM
% contains at least one `eval` code fragment. The evaluation is
% executed in a sandboxed environment, much like the Pengines
% infrastructure.
%
% A code fragment is represented by a term of this shape:
%
% pre([class(code), ext(Ext)], Text)
eval_dom(DOM0, DOM, Options) :-
contains_eval(DOM0),
!,
in_temporary_module(
Module,
prepare(Module),
md_eval(Module, Options, DOM0, DOM, 0, _)).
prepare(Module) :-
setting(swish:program_space, SpaceLimit),
set_module(Module:program_space(SpaceLimit)),
delete_import_module(Module, user),
add_import_module(Module, swish, start).
%! md_eval(+Module, +Options, +DOM0, -DOM, +FragI0, -FragI1)
md_eval(Module, Options, Pre, Evaluated, I0, I) :-
pre(Pre, eval, Code),
!,
eval(Module, I0, Code, Evaluated, Options),
I is I0 + 1.
md_eval(Module, Options, Compound, Evaluated, I0, I) :-
compound(Compound),
!,
compound_name_arguments(Compound, Name, Args0),
foldl(md_eval(Module, Options), Args0, Args, I0, I),
compound_name_arguments(Evaluated, Name, Args).
md_eval(_, _, DOM, DOM, I, I) :-
!.
:- meta_predicate
call_collect_messages(0, -).
eval(Module, I, Code, div(class(eval), Evaluated), Options) :-
option(time_limit(Limit), Options, 10),
catch(( call_collect_messages(
call_with_time_limit(
Limit,
do_eval(Module, I, Code, Evaluated0, Options)),
Messages),
append(Evaluated0, Messages, Evaluated)
),
Error,
failed(Error, Evaluated)).
do_eval(Module, I, Code, [div(class(output), DOM)], _Options) :-
debug(md(eval), 'Evaluating ~p', [Code]),
format(atom(Id), 'eval://~w-~w', [Module, I]),
with_output_to(
codes(Codes),
setup_call_cleanup(
open_string(Code, In),
load_files(Module:Id,
[ stream(In),
sandboxed(true)
]),
close(In))),
eval_to_dom(Codes, DOM).
eval_to_dom(Codes, DOM) :-
phrase(is_html, Codes),
E = error(_,_),
catch(setup_call_cleanup(
open_string(Codes, In),
load_html(In, DOM, []),
close(In)),
E, fail),
!.
eval_to_dom(Codes, DOM) :-
wiki_codes_to_dom(Codes, [], DOM).
is_html -->
blanks, "<", tag(Tag),
string(_),
"</", tag(Tag), ">", blanks.
tag([H|T]) -->
alpha(H),
alphas(T).
alpha(H) -->
[H],
{ between(0'a, 0'z, H) }.
alphas([H|T]) -->
alpha(H),
!,
alphas(T).
alphas([]) -->
[].
contains_eval(DOM) :-
sub_term(Pre, DOM),
nonvar(Pre),
pre(Pre, eval, _),
!.
pre(pre(Attrs, Text), Ext, Text) :-
atomic(Text),
is_list(Attrs),
ground(Attrs),
memberchk(ext(Ext), Attrs).
:- thread_local
saved_message/1.
failed(Error, [div(class(error), Message)]) :-
message_to_string(Error, Message).
call_collect_messages(Goal, Messages) :-
setup_call_cleanup(
asserta((user:thread_message_hook(Term, Kind, Lines) :-
save_message(Term, Kind, Lines)), Ref),
Goal,
collect_messages(Ref, Messages)).
save_message(_Term, Kind, Lines) :-
kind_prefix(Kind, Prefix),
with_output_to(
string(Msg),
print_message_lines(current_output, Prefix, Lines)),
assertz(saved_message(pre(class([eval,Kind]), Msg))).
kind_prefix(error, '% ERROR: ').
kind_prefix(warning, '% Warning: ').
collect_messages(Ref, Messages) :-
erase(Ref),
findall(Msg, retract(saved_message(Msg)), Messages).
/*******************************
* CONDITIONS *
*******************************/
%! swish_provides(?Term) is nondet.
%
% True when Term describes a provided feature of the current SWISH
% instances. Provided Term values are:
%
% - plugin(Name)
% True when Name is the name of a loaded plugin
%
% In addition, plugins may provide additional terms by adding facts to
% swish_config:config(provides, Term).
swish_provides(plugin(Plugin)) :-
swish_has_plugin(Plugin).
swish_provides(Term) :-
provides(Term).
%! swish_has_plugin(+Name) is nondet.
%
% True when Name is the name of a loaded plugin. This predicate is
% intended for dynamic markdown pages.
swish_has_plugin(Name) :-
var(Name), !,
distinct(Dir,
absolute_file_name(
config_enabled(.),
Dir,
[ solutions(all),
file_type(directory)
])),
directory_files(Dir, Files),
member(File, Files),
directory_file_path(Dir, File, Source),
source_file(Source),
file_name_extension(Name, _, File).
swish_has_plugin(Name) :-
must_be(atom, Name),
absolute_file_name(
config_enabled(Name),
File,
[ solutions(all),
file_type(prolog)
]),
source_file(File),
!.
sandbox:safe_primitive(md_eval:swish_provides(_)).
/*******************************
* ACTIVATE *
*******************************/
:- multifile
swish_markdown:dom_expansion/2.
swish_markdown:dom_expansion(DOM0, DOM) :-
setting(time_limit, Limit),
Limit > 0,
eval_dom(DOM0, DOM, [time_limit(Limit)]).