Initial data commit

Task/Execute-a-Markov-algorithm/Prolog/execute-a-markov-algorithm-1.pro

@@ -0,0 +1,88 @@
+:- module('markov.pl', [markov/3, apply_markov/3]).
+
+:- use_module(library(lambda)).
+
+apply_markov(Rules, Sentence, Replacement) :-
+    maplist(\X^Y^(atom_chars(X, Ch), phrase(markov(Y), Ch, [])), Rules, TmpRules),
+    % comments produce empty rules
+    exclude(=([]), TmpRules, LstRules),
+
+    atom_chars(Sentence, L),
+    apply_rules(L, LstRules, R),
+    atom_chars(Replacement, R).
+
+apply_rules(In, Rules, Out ) :-
+    apply_one_rule(In, Rules, Out1, Keep_On),
+    (   Keep_On = false
+    ->  Out = Out1
+    ;   apply_rules(Out1, Rules, Out)).
+
+
+apply_one_rule(In, [Rule | Rules], Out, Keep_On) :-
+    extract(Rule, In, Out1, KeepOn),
+    (   KeepOn = false
+    ->  Out = Out1, Keep_On = KeepOn
+    ;   (KeepOn = stop
+        ->  Out = Out1,
+        Keep_On = true
+        ;   apply_one_rule(Out1, Rules, Out, Keep_On))).
+
+apply_one_rule(In, [], In, false) .
+
+
+extract([Pattern, Replace], In, Out, Keep_On) :-
+    (   Replace = [.|Rest]
+    ->  R = Rest
+    ;   R = Replace),
+    (   (append(Pattern, End, T), append(Deb, T, In))
+    ->  extract([Pattern, Replace], End, NewEnd, _Keep_On),
+        append_3(Deb, R, NewEnd, Out),
+        Keep_On = stop
+    ;   Out = In,
+        (   R = Replace
+        ->  Keep_On = true
+        ;   Keep_On = false)).
+
+
+append_3(A, B, C, D) :-
+           append(A, B, T),
+           append(T, C, D).
+
+% creation of the rules
+markov(A) --> line(A).
+
+line(A) --> text(A), newline.
+
+
+newline --> ['\n'], newline.
+newline --> [].
+
+text([]) --> comment([]).
+text(A) --> rule(A).
+
+comment([]) --> ['#'], anything.
+
+anything --> [X], {X \= '\n'}, anything.
+anything --> ['\n'].
+anything --> [].
+
+rule([A,B]) -->
+    pattern(A), whitespaces, ['-', '>'], whitespaces, end_rule(B).
+
+pattern([X | R]) --> [X], {X \= '\n'}, pattern(R).
+pattern([]) --> [].
+
+whitespaces --> ['\t'], whitespace.
+whitespaces --> [' '], whitespace.
+
+whitespace --> whitespaces.
+whitespace --> [].
+
+end_rule([.| A]) --> [.], rest_of_rule(A).
+end_rule(A) --> rest_of_rule(A).
+end_rule([]) --> [].
+
+rest_of_rule(A) --> replacement(A).
+
+replacement([X | R]) --> [X], {X \= '\n'}, replacement(R).
+replacement([]) --> [].