erlang学习：用ETS和DETS存储数据2

今日学习创建一个ETS表

下面是代码实现

-module(lib_trigrams).

-export([make_ets_set/0, make_ets_ordered_set/0]).
for_each_trigram_in_the_english_language(F, A0) ->
  {ok, Bin0} = file:read_file("test.txt"),
  Bin = zlib:gunzip(Bin0),
  scan_word_list(binary_to_list(Bin), F, A0).


scan_word_list([], _, A) ->
  A;
scan_word_list(L, F, A) ->
  {word, L1} = get_next_word(L, []),
  A1 = scan_trigrams([$\s | word], F, A),
  scan_word_list(L1, F, A1).

get_next_word([$\r, $\n | T], L) ->
  {lists:reverse([$\s | L]), T};
get_next_word([H | T], L) ->
  get_next_word(T, [H | L]);
get_next_word([], L) ->
  {lists:reverse([$\s | L]), []}.


scan_trigrams([X, Y, Z], F, A) ->
  F([X, Y, Z], A);
scan_trigrams([X, Y, Z | T], F, A) ->
  A1 = F([X, Y, Z], A),
  scan_trigrams([Y, Z | T], F, A1);
scan_trigrams(_, _, A) ->
  A.


make_ets_ordered_set() -> make_a_set(ordered_set, "trigramsOS.tab").
make_ets_set() -> make_a_set(set, "trigramsS.tab").


make_a_set(Type, FileName) ->
  Tab = ets:new(table, [Type]),
  F = fun(Str, _) -> ets:insert(Tab, {list_to_binary(Str)}) end,
  for_each_trigram_in_the_english_language(F, 0),
  ets:tab2file(Tab, FileName),
  Size = ets:info(Tab, size),
  ets:delete(Tab),
  Size.

书上代码中的reverse没有lists，因此会报错，需要改为lists：reverse

搞了个txt文本之后报错为数据异常，有点没搞明白txt文档里面要存什么数据