/* 

  Mutants in Picat.

  Inspired by the PrologII+ program mutant.p2

  A mutant word is a combination of two words where the suffix of the first word
  is a prefix of the second word.
  The PrologII+ program combined these French words (animals):


      alligator
      tortue
      caribou
      ours
      cheval
      vache
      lapin
      pintade
      hibou
      bouquetin
      chevre

  into these mutant words (go20):

       alligatortue
       caribours
       caribouquetin
       chevalligator
       chevalapin
       vacheval
       vachevre
       lapintade
       hibours
       hibouquetin


  Added mutant_words/5 which "mutant" words from a wordlist, including MinLen
  which is the minimum length of the common pre-/suffix.

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

*/


main => go.


/* 

  Some examples with MinLen 4:

  [abeyance,ancestral,abeyancestral]
  [abeyance,ancestry,abeyancestry]
  [abigail,gaillardia,abigaillardia]
  [ablate,laterite,ablaterite]
  [aboard,boardinghouse,aboardinghouse]
  [aboriginal,inalienable,aboriginalienable]
  [aboriginal,inalterable,aboriginalterable]
  [about,boutique,aboutique]
  [above,aboveboard,aboveboard]
  [above,aboveground,aboveground]


  "Self mutant" words:
  [alfalfa,alfalfa,alfalfalfa]
  [antiperspirant,antiperspirant,antiperspirantiperspirant]
  [beriberi,beriberi,beriberiberi]
  [calendrical,calendrical,calendricalendrical]
  [couscous,couscous,couscouscous]
  [einstein,einstein,einsteinstein]
  [hotshot,hotshot,hotshotshot]
  [murmur,murmur,murmurmur]
  [oshkosh,oshkosh,oshkoshkosh]
  [tarantara,tarantara,tarantarantara]
  [tartar,tartar,tartartar]
  [testes,testes,testestes]

*/

go ?=> 
  File = "unixdict.txt",
  MinLen = 4,
  mutant_words(File,MinLen, X,Y,Z),
  println([X,Y,Z]),
  fail,

  nl.

go => true.


%
% PrologII+ version
% Mutant animals.
%
go2 ?=>
  mutant(X),
  println(X),
  fail,
  
  nl.

go2 => true.



%
% read a word list and find words that can be "mutanted"
%
%
mutant_words(File,MinLen, X,Y,Z) =>

  % Words = $[w(W) : W in read_file_lines(File), length(W) > MinLen],
  % println(words_read),
  % cl_facts(Words),
  cl_facts($[w(W) : W in read_file_lines(File), length(W) > MinLen]),
  println(cl_finished),

  % pick any two (different) words
  w(X),
  w(Y),
  X != Y,
  % X == Y, % self mutant word

  append(A,B,X), % B is the suffix of X
  A != [],
  B.len >= MinLen,
  append(B,C,Y),  % B is the prefix of Y 
  C.len >= MinLen,
  append(X,C,Z), % combine prefix of X and suffix of Y
  not(w(Z)). % don't accept existing words


%
% From PrologII+ program mutant.p2
%
mutant(Z) =>
   animal(X),
   animal(Y),
   append(_A,B,X),
   B != [],
   append(B,C,Y),
   C != [],
   append(X,C,Z).

index(-)
animal("alligator").
animal("tortue").
animal("caribou").
animal("ours").
animal("cheval").
animal("vache").
animal("lapin").
animal("pintade").
animal("hibou").
animal("bouquetin").
animal("chevre").