%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2005-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(edlin_expand).
%% a default expand function for edlin, expanding modules and functions
-export([expand/1, format_matches/1]).
-import(lists, [reverse/1, nthtail/2, prefix/2]).
%% expand(CurrentBefore) ->
%% {yes, Expansion, Matches} | {no, Matches}
%% Try to expand the word before as either a module name or a function
%% name. We can handle white space around the seperating ':' but the
%% function name must be on the same line. CurrentBefore is reversed
%% and over_word/3 reverses the characters it finds. In certain cases
%% possible expansions are printed.
expand(Bef0) ->
{Bef1,Word,_} = edlin:over_word(Bef0, [], 0),
case over_white(Bef1, [], 0) of
{[$:|Bef2],_White,_Nwh} ->
{Bef3,_White1,_Nwh1} = over_white(Bef2, [], 0),
{_,Mod,_Nm} = edlin:over_word(Bef3, [], 0),
expand_function_name(Mod, Word);
{_,_,_} ->
expand_module_name(Word)
end.
expand_module_name(Prefix) ->
match(Prefix, code:all_loaded(), ":").
expand_function_name(ModStr, FuncPrefix) ->
case to_atom(ModStr) of
{ok, Mod} ->
case erlang:module_loaded(Mod) of
true ->
L = Mod:module_info(),
case lists:keyfind(exports, 1, L) of
{_, Exports} ->
match(FuncPrefix, Exports, "(");
_ ->
{no, [], []}
end;
false ->
{no, [], []}
end;
error ->
{no, [], []}
end.
%% if it's a quoted atom, atom_to_list/1 will do the wrong thing.
to_atom(Str) ->
case erl_scan:string(Str) of
{ok, [{atom,_,A}], _} ->
{ok, A};
_ ->
error
end.
match(Prefix, Alts, Extra0) ->
Len = length(Prefix),
Matches = lists:sort(
[{S, A} || {H, A} <- Alts,
prefix(Prefix, S=hd(io_lib:fwrite("~w",[H])))]),
case longest_common_head([N || {N, _} <- Matches]) of
{partial, []} ->
{no, [], Matches}; % format_matches(Matches)};
{partial, Str} ->
case nthtail(Len, Str) of
[] ->
{yes, [], Matches}; % format_matches(Matches)};
Remain ->
{yes, Remain, []}
end;
{complete, Str} ->
Extra = case {Extra0,Matches} of
{"(",[{Str,0}]} -> "()";
{_,_} -> Extra0
end,
{yes, nthtail(Len, Str) ++ Extra, []};
no ->
{no, [], []}
end.
%% Return the list of names L in multiple columns.
format_matches(L) ->
S = format_col(lists:sort(L), []),
["\n" | S].
format_col([], _) -> [];
format_col(L, Acc) -> format_col(L, field_width(L), 0, Acc).
format_col(X, Width, Len, Acc) when Width + Len > 79 ->
format_col(X, Width, 0, ["\n" | Acc]);
format_col([A|T], Width, Len, Acc0) ->
H = case A of
%% If it's a tuple {string(), integer()}, we assume it's an
%% arity, and meant to be printed.
{H0, I} when is_integer(I) ->
H0 ++ "/" ++ integer_to_list(I);
{H1, _} -> H1;
H2 -> H2
end,
Acc = [io_lib:format("~-*s", [Width,H]) | Acc0],
format_col(T, Width, Len+Width, Acc);
format_col([], _, _, Acc) ->
lists:reverse(Acc, "\n").
field_width(L) -> field_width(L, 0).
field_width([{H,_}|T], W) ->
case length(H) of
L when L > W -> field_width(T, L);
_ -> field_width(T, W)
end;
field_width([H|T], W) ->
case length(H) of
L when L > W -> field_width(T, L);
_ -> field_width(T, W)
end;
field_width([], W) when W < 40 ->
W + 4;
field_width([], _) ->
40.
longest_common_head([]) ->
no;
longest_common_head(LL) ->
longest_common_head(LL, []).
longest_common_head([[]|_], L) ->
{partial, reverse(L)};
longest_common_head(LL, L) ->
case same_head(LL) of
true ->
[[H|_]|_] = LL,
LL1 = all_tails(LL),
case all_nil(LL1) of
false ->
longest_common_head(LL1, [H|L]);
true ->
{complete, reverse([H|L])}
end;
false ->
{partial, reverse(L)}
end.
same_head([[H|_]|T1]) -> same_head(H, T1).
same_head(H, [[H|_]|T]) -> same_head(H, T);
same_head(_, []) -> true;
same_head(_, _) -> false.
all_tails(LL) -> all_tails(LL, []).
all_tails([[_|T]|T1], L) -> all_tails(T1, [T|L]);
all_tails([], L) -> L.
all_nil([]) -> true;
all_nil([[] | Rest]) -> all_nil(Rest);
all_nil(_) -> false.
%% over_white(Chars, InitialStack, InitialCount) ->
%% {RemainingChars,CharStack,Count}.
over_white([$\s|Cs], Stack, N) ->
over_white(Cs, [$\s|Stack], N+1);
over_white([$\t|Cs], Stack, N) ->
over_white(Cs, [$\t|Stack], N+1);
over_white(Cs, Stack, N) when is_list(Cs) ->
{Cs,Stack,N}.
