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authorErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
committerErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
commit84adefa331c4159d432d22840663c38f155cd4c1 (patch)
treebff9a9c66adda4df2106dfd0e5c053ab182a12bd /lib/stdlib/src/edlin.erl
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The R13B03 release.OTP_R13B03
Diffstat (limited to 'lib/stdlib/src/edlin.erl')
-rw-r--r--lib/stdlib/src/edlin.erl575
1 files changed, 575 insertions, 0 deletions
diff --git a/lib/stdlib/src/edlin.erl b/lib/stdlib/src/edlin.erl
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+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1996-2009. 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).
+
+%% A simple Emacs-like line editor.
+%% About Latin-1 characters: see the beginning of erl_scan.erl.
+
+-export([init/0,start/1,edit_line/2,prefix_arg/1]).
+-export([erase_line/1,erase_inp/1,redraw_line/1]).
+-export([length_before/1,length_after/1,prompt/1]).
+%%-export([expand/1]).
+
+-export([edit_line1/2]).
+
+-import(lists, [reverse/1, reverse/2]).
+
+%-import([nthtail/2, keysearch/3, prefix/2]).
+
+-export([over_word/3]).
+
+
+%% A Continuation has the structure:
+%% {line,Prompt,CurrentLine,EditPrefix}
+
+%% init()
+%% Initialise the line editor. This must be done once per process using
+%% the editor.
+
+init() ->
+ put(kill_buffer, []).
+
+%% start(Prompt)
+%% edit(Characters, Continuation)
+%% Return
+%% {done,Line,Rest,Requests}
+%% {more_chars,Cont,Requests}
+%% {blink,Cont,Requests}
+%% {undefined,Char,Rest,Cont,Requests}
+
+start(Pbs) ->
+ {more_chars,{line,Pbs,{[],[]},none},[{put_chars,unicode,Pbs}]}.
+
+edit_line(Cs, {line,P,L,{blink,N}}) ->
+ edit(Cs, P, L, none, [{move_rel,N}]);
+edit_line(Cs, {line,P,L,M}) ->
+ edit(Cs, P, L, M, []).
+
+edit_line1(Cs, {line,P,L,{blink,N}}) ->
+ edit(Cs, P, L, none, [{move_rel,N}]);
+edit_line1(Cs, {line,P,{[],[]},none}) ->
+ {more_chars, {line,P,{lists:reverse(Cs),[]},none},[{put_chars, unicode, Cs}]};
+edit_line1(Cs, {line,P,L,M}) ->
+ edit(Cs, P, L, M, []).
+
+edit([C|Cs], P, Line, {blink,_}, [_|Rs]) -> %Remove blink here
+ edit([C|Cs], P, Line, none, Rs);
+edit([C|Cs], P, {Bef,Aft}, Prefix, Rs0) ->
+ case key_map(C, Prefix) of
+ meta ->
+ edit(Cs, P, {Bef,Aft}, meta, Rs0);
+ meta_left_sq_bracket ->
+ edit(Cs, P, {Bef,Aft}, meta_left_sq_bracket, Rs0);
+ ctlx ->
+ edit(Cs, P, {Bef,Aft}, ctlx, Rs0);
+ new_line ->
+ {done, reverse(Bef, Aft ++ "\n"), Cs,
+ reverse(Rs0, [{move_rel,length(Aft)},{put_chars,unicode,"\n"}])};
+ redraw_line ->
+ Rs1 = erase(P, Bef, Aft, Rs0),
+ Rs = redraw(P, Bef, Aft, Rs1),
+ edit(Cs, P, {Bef,Aft}, none, Rs);
+ tab_expand ->
+ {expand, Bef, Cs,
+ {line, P, {Bef, Aft}, none},
+ reverse(Rs0)};
+
+%% tab ->
+%% %% Always redraw the line since expand/1 might have printed
+%% %% possible expansions.
+%% case expand(Bef) of
+%% {yes,Str} ->
+%% edit([redraw_line|
+%% (Str ++ Cs)], P, {Bef,Aft}, none, Rs0);
+%% no ->
+%% %% don't beep if there's only whitespace before
+%% %% us - user may have pasted in a lot of indented stuff.
+%% case whitespace_only(Bef) of
+%% false ->
+%% edit([redraw_line|Cs], P, {Bef,Aft}, none,
+%% [beep|Rs0]);
+%% true ->
+%% edit([redraw_line|Cs], P, {Bef,Aft}, none, [Rs0])
+%% end
+%% end;
+ {undefined,C} ->
+ {undefined,{none,Prefix,C},Cs,{line,P,{Bef,Aft},none},
+ reverse(Rs0)};
+ Op ->
+ case do_op(Op, Bef, Aft, Rs0) of
+ {blink,N,Line,Rs} ->
+ edit(Cs, P, Line, {blink,N}, Rs);
+ {Line,Rs} ->
+ edit(Cs, P, Line, none, Rs)
+ end
+ end;
+edit([], P, L, {blink,N}, Rs) ->
+ {blink,{line,P,L,{blink,N}},reverse(Rs)};
+edit([], P, L, Prefix, Rs) ->
+ {more_chars,{line,P,L,Prefix},reverse(Rs)};
+edit(eof, _, {Bef,Aft}, _, Rs) ->
+ {done,reverse(Bef, Aft),[],reverse(Rs, [{move_rel,length(Aft)}])}.
+
+%% %% Assumes that arg is a string
+%% %% Horizontal whitespace only.
+%% whitespace_only([]) ->
+%% true;
+%% whitespace_only([C|Rest]) ->
+%% case C of
+%% $\s ->
+%% whitespace_only(Rest);
+%% $\t ->
+%% whitespace_only(Rest);
+%% _ ->
+%% false
+%% end.
+
+%% prefix_arg(Argument)
+%% Take a prefix argument and return its numeric value.
+
+prefix_arg(none) -> 1;
+prefix_arg({ctlu,N}) -> N;
+prefix_arg(N) -> N.
+
+%% key_map(Char, Prefix)
+%% Map a character and a prefix to an action.
+
+key_map(A, _) when is_atom(A) -> A; % so we can push keywords
+key_map($\^A, none) -> beginning_of_line;
+key_map($\^B, none) -> backward_char;
+key_map($\^D, none) -> forward_delete_char;
+key_map($\^E, none) -> end_of_line;
+key_map($\^F, none) -> forward_char;
+key_map($\^H, none) -> backward_delete_char;
+key_map($\t, none) -> tab_expand;
+key_map($\^L, none) -> redraw_line;
+key_map($\n, none) -> new_line;
+key_map($\^K, none) -> kill_line;
+key_map($\r, none) -> new_line;
+key_map($\^T, none) -> transpose_char;
+key_map($\^U, none) -> ctlu;
+key_map($\^], none) -> auto_blink;
+key_map($\^X, none) -> ctlx;
+key_map($\^Y, none) -> yank;
+key_map($\e, none) -> meta;
+key_map($), Prefix) when Prefix =/= meta -> {blink,$),$(};
+key_map($}, Prefix) when Prefix =/= meta -> {blink,$},${};
+key_map($], Prefix) when Prefix =/= meta -> {blink,$],$[};
+key_map($B, meta) -> backward_word;
+key_map($D, meta) -> kill_word;
+key_map($F, meta) -> forward_word;
+key_map($T, meta) -> transpose_word;
+key_map($Y, meta) -> yank_pop;
+key_map($b, meta) -> backward_word;
+key_map($d, meta) -> kill_word;
+key_map($f, meta) -> forward_word;
+key_map($t, meta) -> transpose_word;
+key_map($y, meta) -> yank_pop;
+key_map($\177, none) -> backward_delete_char;
+key_map($\177, meta) -> backward_kill_word;
+key_map($[, meta) -> meta_left_sq_bracket;
+key_map($D, meta_left_sq_bracket) -> backward_char;
+key_map($C, meta_left_sq_bracket) -> forward_char;
+key_map(C, none) when C >= $\s ->
+ {insert,C};
+key_map(C, _) -> {undefined,C}.
+
+%% do_op(Action, Before, After, Requests)
+
+do_op({insert,C}, Bef, [], Rs) ->
+ {{[C|Bef],[]},[{put_chars, unicode,[C]}|Rs]};
+do_op({insert,C}, Bef, Aft, Rs) ->
+ {{[C|Bef],Aft},[{insert_chars, unicode, [C]}|Rs]};
+%% do blink after $$
+do_op({blink,C,M}, Bef=[$$,$$|_], Aft, Rs) ->
+ N = over_paren(Bef, C, M),
+ {blink,N+1,{[C|Bef],Aft},[{move_rel,-(N+1)},{insert_chars, unicode,[C]}|Rs]};
+%% don't blink after a $
+do_op({blink,C,_}, Bef=[$$|_], Aft, Rs) ->
+ do_op({insert,C}, Bef, Aft, Rs);
+%do_op({blink,C,M}, Bef, [], Rs) ->
+% N = over_paren(Bef, C, M),
+% {blink,N+1,{[C|Bef],[]},[{move_rel,-(N+1)},{put_chars,[C]}|Rs]};
+do_op({blink,C,M}, Bef, Aft, Rs) ->
+ case over_paren(Bef, C, M) of
+ beep ->
+ {{[C|Bef], Aft}, [beep,{insert_chars, unicode, [C]}|Rs]};
+ N -> {blink,N+1,{[C|Bef],Aft},
+ [{move_rel,-(N+1)},{insert_chars, unicode,[C]}|Rs]}
+ end;
+do_op(auto_blink, Bef, Aft, Rs) ->
+ case over_paren_auto(Bef) of
+ {N, Paren} ->
+ {blink,N+1,
+ {[Paren|Bef], Aft},[{move_rel,-(N+1)},{insert_chars, unicode,[Paren]}|Rs]};
+ % N is likely 0
+ N -> {blink,N+1,{Bef,Aft},
+ [{move_rel,-(N+1)}|Rs]}
+ end;
+do_op(forward_delete_char, Bef, [_|Aft], Rs) ->
+ {{Bef,Aft},[{delete_chars,1}|Rs]};
+do_op(backward_delete_char, [_|Bef], Aft, Rs) ->
+ {{Bef,Aft},[{delete_chars,-1}|Rs]};
+do_op(transpose_char, [C1,C2|Bef], [], Rs) ->
+ {{[C2,C1|Bef],[]},[{put_chars, unicode,[C1,C2]},{move_rel,-2}|Rs]};
+do_op(transpose_char, [C2|Bef], [C1|Aft], Rs) ->
+ {{[C2,C1|Bef],Aft},[{put_chars, unicode,[C1,C2]},{move_rel,-1}|Rs]};
+do_op(kill_word, Bef, Aft0, Rs) ->
+ {Aft1,Kill0,N0} = over_non_word(Aft0, [], 0),
+ {Aft,Kill,N} = over_word(Aft1, Kill0, N0),
+ put(kill_buffer, reverse(Kill)),
+ {{Bef,Aft},[{delete_chars,N}|Rs]};
+do_op(backward_kill_word, Bef0, Aft, Rs) ->
+ {Bef1,Kill0,N0} = over_non_word(Bef0, [], 0),
+ {Bef,Kill,N} = over_word(Bef1, Kill0, N0),
+ put(kill_buffer, Kill),
+ {{Bef,Aft},[{delete_chars,-N}|Rs]};
+do_op(kill_line, Bef, Aft, Rs) ->
+ put(kill_buffer, Aft),
+ {{Bef,[]},[{delete_chars,length(Aft)}|Rs]};
+do_op(yank, Bef, [], Rs) ->
+ Kill = get(kill_buffer),
+ {{reverse(Kill, Bef),[]},[{put_chars, unicode,Kill}|Rs]};
+do_op(yank, Bef, Aft, Rs) ->
+ Kill = get(kill_buffer),
+ {{reverse(Kill, Bef),Aft},[{insert_chars, unicode,Kill}|Rs]};
+do_op(forward_char, Bef, [C|Aft], Rs) ->
+ {{[C|Bef],Aft},[{move_rel,1}|Rs]};
+do_op(backward_char, [C|Bef], Aft, Rs) ->
+ {{Bef,[C|Aft]},[{move_rel,-1}|Rs]};
+do_op(forward_word, Bef0, Aft0, Rs) ->
+ {Aft1,Bef1,N0} = over_non_word(Aft0, Bef0, 0),
+ {Aft,Bef,N} = over_word(Aft1, Bef1, N0),
+ {{Bef,Aft},[{move_rel,N}|Rs]};
+do_op(backward_word, Bef0, Aft0, Rs) ->
+ {Bef1,Aft1,N0} = over_non_word(Bef0, Aft0, 0),
+ {Bef,Aft,N} = over_word(Bef1, Aft1, N0),
+ {{Bef,Aft},[{move_rel,-N}|Rs]};
+do_op(beginning_of_line, [C|Bef], Aft, Rs) ->
+ {{[],reverse(Bef, [C|Aft])},[{move_rel,-(length(Bef)+1)}|Rs]};
+do_op(beginning_of_line, [], Aft, Rs) ->
+ {{[],Aft},Rs};
+do_op(end_of_line, Bef, [C|Aft], Rs) ->
+ {{reverse(Aft, [C|Bef]),[]},[{move_rel,length(Aft)+1}|Rs]};
+do_op(end_of_line, Bef, [], Rs) ->
+ {{Bef,[]},Rs};
+do_op(beep, Bef, Aft, Rs) ->
+ {{Bef,Aft},[beep|Rs]};
+do_op(_, Bef, Aft, Rs) ->
+ {{Bef,Aft},[beep|Rs]}.
+
+%% over_word(Chars, InitialStack, InitialCount) ->
+%% {RemainingChars,CharStack,Count}
+%% over_non_word(Chars, InitialStack, InitialCount) ->
+%% {RemainingChars,CharStack,Count}
+%% Step over word/non-word characters pushing the stepped over ones on
+%% the stack.
+
+over_word([C|Cs], Stack, N) ->
+ case word_char(C) of
+ true -> over_word(Cs, [C|Stack], N+1);
+ false -> {[C|Cs],Stack,N}
+ end;
+over_word([], Stack, N) when is_integer(N) ->
+ {[],Stack,N}.
+
+over_non_word([C|Cs], Stack, N) ->
+ case word_char(C) of
+ true -> {[C|Cs],Stack,N};
+ false -> over_non_word(Cs, [C|Stack], N+1)
+ end;
+over_non_word([], Stack, N) ->
+ {[],Stack,N}.
+
+word_char(C) when C >= $A, C =< $Z -> true;
+word_char(C) when C >= $�, C =< $�, C =/= $� -> true;
+word_char(C) when C >= $a, C =< $z -> true;
+word_char(C) when C >= $�, C =< $�, C =/= $� -> true;
+word_char(C) when C >= $0, C =< $9 -> true;
+word_char(C) when C =:= $_ -> true;
+word_char(C) when C =:= $. -> true; % accept dot-separated names
+word_char(_) -> false.
+
+%% over_white(Chars, InitialStack, InitialCount) ->
+%% {RemainingChars,CharStack,Count}
+
+%% over_white([$\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) ->
+%% {Cs,Stack,N}.
+
+%% over_paren(Chars, Paren, Match)
+%% over_paren(Chars, Paren, Match, Depth, N)
+%% Step over parentheses until matching Paren is found at depth 0. Don't
+%% do proper parentheses matching check. Paren has NOT been added.
+
+over_paren(Chars, Paren, Match) ->
+ over_paren(Chars, Paren, Match, 1, 1, []).
+
+
+over_paren([C,$$,$$|Cs], Paren, Match, D, N, L) ->
+ over_paren([C|Cs], Paren, Match, D, N+2, L);
+over_paren([_,$$|Cs], Paren, Match, D, N, L) ->
+ over_paren(Cs, Paren, Match, D, N+2, L);
+over_paren([Match|_], _Paren, Match, 1, N, _) ->
+ N;
+over_paren([Match|Cs], Paren, Match, D, N, [Match|L]) ->
+ over_paren(Cs, Paren, Match, D-1, N+1, L);
+over_paren([Paren|Cs], Paren, Match, D, N, L) ->
+ over_paren(Cs, Paren, Match, D+1, N+1, [Match|L]);
+
+over_paren([$)|Cs], Paren, Match, D, N, L) ->
+ over_paren(Cs, Paren, Match, D, N+1, [$(|L]);
+over_paren([$]|Cs], Paren, Match, D, N, L) ->
+ over_paren(Cs, Paren, Match, D, N+1, [$[|L]);
+over_paren([$}|Cs], Paren, Match, D, N, L) ->
+ over_paren(Cs, Paren, Match, D, N+1, [${|L]);
+
+over_paren([$(|Cs], Paren, Match, D, N, [$(|L]) ->
+ over_paren(Cs, Paren, Match, D, N+1, L);
+over_paren([$[|Cs], Paren, Match, D, N, [$[|L]) ->
+ over_paren(Cs, Paren, Match, D, N+1, L);
+over_paren([${|Cs], Paren, Match, D, N, [${|L]) ->
+ over_paren(Cs, Paren, Match, D, N+1, L);
+
+over_paren([$(|_], _, _, _, _, _) ->
+ beep;
+over_paren([$[|_], _, _, _, _, _) ->
+ beep;
+over_paren([${|_], _, _, _, _, _) ->
+ beep;
+
+over_paren([_|Cs], Paren, Match, D, N, L) ->
+ over_paren(Cs, Paren, Match, D, N+1, L);
+over_paren([], _, _, _, _, _) ->
+ 0.
+
+over_paren_auto(Chars) ->
+ over_paren_auto(Chars, 1, 1, []).
+
+
+over_paren_auto([C,$$,$$|Cs], D, N, L) ->
+ over_paren_auto([C|Cs], D, N+2, L);
+over_paren_auto([_,$$|Cs], D, N, L) ->
+ over_paren_auto(Cs, D, N+2, L);
+
+over_paren_auto([$(|_], _, N, []) ->
+ {N, $)};
+over_paren_auto([$[|_], _, N, []) ->
+ {N, $]};
+over_paren_auto([${|_], _, N, []) ->
+ {N, $}};
+
+over_paren_auto([$)|Cs], D, N, L) ->
+ over_paren_auto(Cs, D, N+1, [$(|L]);
+over_paren_auto([$]|Cs], D, N, L) ->
+ over_paren_auto(Cs, D, N+1, [$[|L]);
+over_paren_auto([$}|Cs], D, N, L) ->
+ over_paren_auto(Cs, D, N+1, [${|L]);
+
+over_paren_auto([$(|Cs], D, N, [$(|L]) ->
+ over_paren_auto(Cs, D, N+1, L);
+over_paren_auto([$[|Cs], D, N, [$[|L]) ->
+ over_paren_auto(Cs, D, N+1, L);
+over_paren_auto([${|Cs], D, N, [${|L]) ->
+ over_paren_auto(Cs, D, N+1, L);
+
+over_paren_auto([_|Cs], D, N, L) ->
+ over_paren_auto(Cs, D, N+1, L);
+over_paren_auto([], _, _, _) ->
+ 0.
+
+%% erase_line(Line)
+%% erase_inp(Line)
+%% redraw_line(Line)
+%% length_before(Line)
+%% length_after(Line)
+%% prompt(Line)
+%% Various functions for accessing bits of a line.
+
+erase_line({line,Pbs,{Bef,Aft},_}) ->
+ reverse(erase(Pbs, Bef, Aft, [])).
+
+erase_inp({line,_,{Bef,Aft},_}) ->
+ reverse(erase([], Bef, Aft, [])).
+
+erase(Pbs, Bef, Aft, Rs) ->
+ [{delete_chars,-length(Pbs)-length(Bef)},{delete_chars,length(Aft)}|Rs].
+
+redraw_line({line,Pbs,{Bef,Aft},_}) ->
+ reverse(redraw(Pbs, Bef, Aft, [])).
+
+redraw(Pbs, Bef, Aft, Rs) ->
+ [{move_rel,-length(Aft)},{put_chars, unicode,reverse(Bef, Aft)},{put_chars, unicode,Pbs}|Rs].
+
+length_before({line,Pbs,{Bef,_Aft},_}) ->
+ length(Pbs) + length(Bef).
+
+length_after({line,_,{_Bef,Aft},_}) ->
+ length(Aft).
+
+prompt({line,Pbs,_,_}) ->
+ Pbs.
+
+%% %% expand(CurrentBefore) ->
+%% %% {yes,Expansion} | no
+%% %% Try to expand the word before as either a module name or a function
+%% %% name. We can handle white space around the seperating ':' but the
+%% %% function name must be on the same line. CurrentBefore is reversed
+%% %% and over_word/3 reverses the characters it finds. In certain cases
+%% %% possible expansions are printed.
+
+%% expand(Bef0) ->
+%% {Bef1,Word,_} = over_word(Bef0, [], 0),
+%% case over_white(Bef1, [], 0) of
+%% {[$:|Bef2],_White,_Nwh} ->
+%% {Bef3,_White1,_Nwh1} = over_white(Bef2, [], 0),
+%% {_,Mod,_Nm} = 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) ->
+%% Mod = list_to_atom(ModStr),
+%% case erlang:module_loaded(Mod) of
+%% true ->
+%% L = apply(Mod, module_info, []),
+%% case keysearch(exports, 1, L) of
+%% {value, {_, Exports}} ->
+%% match(FuncPrefix, Exports, "(");
+%% _ ->
+%% no
+%% end;
+%% false ->
+%% no
+%% end.
+
+%% match(Prefix, Alts, Extra) ->
+%% Matches = match1(Prefix, Alts),
+%% case longest_common_head([N || {N,_} <- Matches]) of
+%% {partial, []} ->
+%% print_matches(Matches),
+%% no;
+%% {partial, Str} ->
+%% case nthtail(length(Prefix), Str) of
+%% [] ->
+%% print_matches(Matches),
+%% {yes, []};
+%% Remain ->
+%% {yes, Remain}
+%% end;
+%% {complete, Str} ->
+%% {yes, nthtail(length(Prefix), Str) ++ Extra};
+%% no ->
+%% no
+%% end.
+
+%% %% Print the list of names L in multiple columns.
+%% print_matches(L) ->
+%% io:nl(),
+%% col_print(lists:sort(L)),
+%% ok.
+
+%% col_print([]) -> ok;
+%% col_print(L) -> col_print(L, field_width(L), 0).
+
+%% col_print(X, Width, Len) when Width + Len > 79 ->
+%% io:nl(),
+%% col_print(X, Width, 0);
+%% col_print([{H0,A}|T], Width, Len) ->
+%% H = if
+%% %% If the second element is an integer, we assume it's an
+%% %% arity, and meant to be printed.
+%% integer(A) ->
+%% H0 ++ "/" ++ integer_to_list(A);
+%% true ->
+%% H0
+%% end,
+%% io:format("~-*s",[Width,H]),
+%% col_print(T, Width, Len+Width);
+%% col_print([], _, _) ->
+%% io:nl().
+
+%% field_width([{H,_}|T]) -> field_width(T, length(H)).
+
+%% 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.
+
+%% match1(Prefix, Alts) ->
+%% match1(Prefix, Alts, []).
+
+%% match1(Prefix, [{H,A}|T], L) ->
+%% case prefix(Prefix, Str = atom_to_list(H)) of
+%% true ->
+%% match1(Prefix, T, [{Str,A}|L]);
+%% false ->
+%% match1(Prefix, T, L)
+%% end;
+%% match1(_, [], L) ->
+%% L.
+
+%% 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.