1/*  Part of SWI-Prolog
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2007-2017, University of Amsterdam
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(doc_util,
   36          [ insert_alias/2,             % +Path, -Aliased
   37            expand_alias/2,             % +Aliased, -Path
   38            ensure_slash_end/2,         % +Dir, -DirSlash
   39            atom_pi/2                   % +Atom, -PI
   40          ]).

   47                 /*******************************
   48                 *     PATH ALIAS PROCESSING    *
   49                 *******************************/

 insert_alias(+Path0, -Path) is det

Translate a native path to an aliased path. Path aliases are defined by path_alias/2. Aliased paths are re-translated into native form using expand_alias/2.

   57insert_alias(Path0, Path) :-
   58    path_alias(Alias, Prefix),
   59    atom_concat(Prefix, PostFix, Path0),
   60    !,
   61    atom_concat(Alias, PostFix, Path).
   62insert_alias(Path, Path).

 expand_alias(+Path0, -Path) is det

Translate an aliased path to a native path.

   69expand_alias(Path0, Path) :-
   70    path_alias(Alias, Prefix),
   71    atom_concat(Alias, Postfix, Path0),
   72    !,
   73    atom_concat(Prefix, Postfix, Path).
   74expand_alias(Path, Path).

 path_alias(?Alias, ?Path) is nondet

True if Alias: is an alias for Path. This is used to rewrite paths below the SWI-Prolog home to give them shorter and fixed names.

   83path_alias('/_SWI_/', Dir) :-
   84    current_prolog_flag(home, Dir0),
   85    ensure_slash_end(Dir0, Dir).
   86path_alias('/_CWD_/', Dir) :-
   87    working_directory(Dir0, Dir0),
   88    ensure_slash_end(Dir0, Dir).
   89
   90
   91                 /*******************************
   92                 *      MISC PATH OPERATIONS    *
   93                 *******************************/

 ensure_slash_end(+Dir, -DirSlash) is det

Ensure Dir ends with a /.

   99ensure_slash_end(Dir, Dir) :-
  100    sub_atom(Dir, _, _, 0, /),
  101    !.
  102ensure_slash_end(Dir0, Dir) :-
  103    atom_concat(Dir0, /, Dir).
  104
  105                 /*******************************
  106                 *          PREDICATES          *
  107                 *******************************/

 atom_pi(+Atom, -PI) is det

Translate an external predicate indicator representated as an atom into a predicate indicator term. If Atom contains <module>:, PI is qialified. If no arity is provided it is a term Name/_, i.e., with unbound arity.

  117atom_pi(Atom, Module:PI) :-
  118    atomic_list_concat([Module, PIAtom], :, Atom),
  119    Module \== '',
  120    forall(sub_atom(Module, _,1,_,C), char_type(C,alnum)),
  121    !,
  122    atom_pi2(PIAtom, PI).
  123atom_pi(Atom, PI) :-
  124    atom_pi2(Atom, PI).
  125
  126atom_pi2(Atom, Name//Arity) :-
  127    sub_atom(Atom, B, _, A, //),
  128    sub_atom(Atom, _, A, 0, ArityA),
  129    atom_number(ArityA, Arity),
  130    !,
  131    sub_atom(Atom, 0, B, _, Name).
  132atom_pi2(Atom, Name/Arity) :-
  133    sub_atom(Atom, B, _, A, /),
  134    sub_atom(Atom, _, A, 0, ArityA),
  135    atom_number(ArityA, Arity),
  136    !,
  137    sub_atom(Atom, 0, B, _, Name).
  138atom_pi2(Name, Name/_)