/* 

  Generate all spellings of Henning Mankell (and Kjellerstrand) in Picat v3.

  This is a recurring problem for me: Generating "all" possible
  spellings of Henning Mankell (and Kjellerstrand) given a grammar 
  (or regular expression).

  I have written about this before:
  - Regular expressions in Gecode
    http://www.hakank.org/constraint_programming_blog/2009/04/regular_expressions_in_gecode.html
    This blog post contains further links and references.

  - Icon program for the Henning Mankell problem:
    http://www.hakank.org/unicon/pattern_generation.icn

  - B-Prolog program 
    http://www.hakank.org/bprolog/mankell.pl

  * "Henning Mankell" should generate 1296 different strings
  * "Kjellerstrand" should generate these 48 different spellings
     kjellstad, kjellstand, kjellstrad, kjellstrand, kjellbad, kjellband, kjellbrad, 
     kjellbrand, kjellerstad, kjellerstand, kjellerstrad, 
         kjellerstrand, 
     kjellerbad, kjellerband, kjellerbrad, kjellerbrand, kjellarstad, kjellarstand, 
     kjellarstrad, kjellarstrand, kjellarbad, kjellarband, kjellarbrad, 
     kjellarbrand, källstad, källstand, källstrad, källstrand, källbad, källband, 
     källbrad, källbrand, källerstad, källerstand, källerstrad, källerstrand, 
     källerbad, källerband, källerbrad, källerbrand, källarstad, källarstand, 
     källarstrad, källarstrand, källarbad, källarband, källarbrad, källarbrand
    

  Picat v3 introduced Definite Clause Grammars and support for Horn clauses.
  This is a port of my SWI-Prolog program http://hakank.org/swi_prolog/

  For non DCG versions, see http://hakank.org/picat/mankell.pi

  This Picat model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

import util.


main => go.

go :-
        println("Henning Mankell1"),
        mankell,
        nl,
        println("Henning Mankell2"),
        mankell2,
        nl,
        println("Kjellerstrand1"),
        kjellerstrand1,
        nl,
        println("Kjellerstrand2"),
        kjellerstrand2,
        nl,
        println("Kjellerstrand3"),
        kjellerstrand3,
        nl,
        println("Kjellerstrand4"),
        kjellerstrand4,
        nl.

go.

%
% The Henning Mankell problem.
%
% Given this regular expression, generate all the
% possible spellings of 'henning mankel':
%  [hm][ea](nk|n|nn)(ing|ell|all) [hm][ea](nk|n|nn)(ing|ell|all) 
% 
smankell1 --> hm, ea, nknnm, ingellall.
hm --> [h].
hm --> [m].
ea --> [e].
ea --> [a].
nknnm --> [nk].
nknnm --> [n].
nknnm --> [nn].
ingellall --> [ing].
ingellall --> [ell].
ingellall --> [all].

smankell --> smankell1,[' '],smankell1.

mankell :-
        showall(smankell).

% [hm][ea](nk|n|nn)(ing|ell|all)
smankell2_1 --> ("h";"m"),("e";"a"),("nk";"n";"nn"),("ing";"ell";"all").

smankell2 --> smankell2_1," ", smankell2_1.

mankell2 :- showall(smankell2).


%
% This regular expression is for (most of) the misspellings
% of my last name, which actually is Kjellerstrand.
%
%    k(je|ä)ll(er|ar)?(st|b)r?an?d 
%

% This is more like the original regular expression. And that may be
% good or bad...
%
% Note: Picat v3.0 don't support alternatives using "|", we can use ";" instead.
%
skjellerstrand1 --> 
        [k], ([je];["ä"]), [ll], ([] ; [er] ; [ar]), 
        ([st] ; [b]),
        ([] ; [r]), [a], ([] ; [n]), [d].

kjellerstrand1 :-
        showall(skjellerstrand1).

%
% Alternative version.
%
skjellerstrand2 --> [k], je, [ll], erar, stb, r_star, [a], n_star, [d].
je      --> [je] ; ["ä"].
erar    --> [] ; [er] ; [ar].
stb     --> [st] ; [b].
r_star  --> [] ; [r].
n_star  --> [] ; [n].
d       --> [d]. 

kjellerstrand2 :-
        showall(skjellerstrand2).

%
% Alternative version.
%
skjellerstrand3 --> [k], je3, [ll], erar3, stb3, r_star3, [a], n_star3, [d].
je3      --> [je].
je3      --> ['ä'].
erar3    --> [].
erar3    --> [er].
erar3    --> [ar].
stb3     --> [st].
stb3     --> [b].
r_star3  --> [].
r_star3  --> [r].
n_star3  --> [].
n_star3  --> [n].
d3       --> [d]. 


kjellerstrand3 :-
        showall(skjellerstrand3).

%
% Using strings directly. Quite much like the regexp:
%     k(je|ä)ll(er|ar)?(st|b)r?an?d
% 
skjellerstrand4 -->
        "k", ("je" ; "ä"), "ll", ("" ; "er" ; "ar"), ("st" ; "b"), ("" ; "r"), "a", (""; "n"), "d".

kjellerstrand4 :- 
        showall(skjellerstrand4).


%
% Show all the generated names for the grammar Grammar.
% 
showall(Grammar) :-
        L = findall(S, (call(Grammar, S, []))),
        bp.length(L, Len),
        foreach(A in L)
          println(A.map(to_string).join(''))
        end,
        println(len=Len),        
        nl.