getty 13 лет назад
Родитель
Сommit
7e5ba67478
1 измененных файлов с 64 добавлено и 0 удалено
  1. 64 0
      src/word_split.erl

+ 64 - 0
src/word_split.erl

@@ -0,0 +1,64 @@
+-module(word_split).
+-export([words/1, to_list/1, words_from_file/1]).
+
+% data WordState = {chunk, S} | {segment, L, C, R}
+
+nil() ->
+    nil.
+
+singleton(S) ->
+    {single, S}.
+
+conc(A, B) ->
+    {conc, A, B}.
+
+to_list(nil) ->
+    [];
+to_list({single, S}) ->
+    [S];
+to_list({conc, A, B}) ->
+    to_list(A) ++ to_list(B).
+
+maybe_word("") ->
+    nil();
+maybe_word(S) ->
+    singleton(S).
+
+process_char(C) ->
+    case lists:member(C, " \t\n\f\l") of
+	true ->
+	    {segment, "", nil(), ""};
+	false ->
+	    {chunk, [C]}
+    end.
+
+combine({chunk, S1}, {chunk, S2}) ->
+    {chunk, S1 ++ S2};
+combine({chunk, S}, {segment, L, C, R}) ->
+    {segment, S ++ L, C, R};
+combine({segment, L, C, R}, {chunk, S}) ->
+    {segment, L, C, R ++ S};
+combine({segment, L1, C1, R1}, {segment, L2, C2, R2}) ->
+    {segment, L1, conc(C1, conc(maybe_word(R1 ++ L2), C2)), R2}.
+
+words(Str) ->
+    T = ebb_flow:map_reduce(fun process_char/1,
+			    fun(X, Y) -> combine(X, Y) end,
+			    Str),
+    case ebb_run:run_distributed(T) of
+	{ok, [{chunk, S}]} ->
+	    to_list(maybe_word(S));
+	{ok, [{segment, L, C, R}]} ->
+	    to_list(conc(maybe_word(L), conc(C, maybe_word(R))));
+	_ ->
+	    error
+    end.
+
+words_from_file(Str) ->
+    case file:read_file(Str) of
+	{ok, Data} ->
+	    io:format("Number of words: ~w\n", [length(words(binary_to_list(Data)))]);
+	_ ->
+	    io:format("File not found!")
+    end.
+