diff options
Diffstat (limited to 'lib/kernel/src/group.erl')
| -rw-r--r-- | lib/kernel/src/group.erl | 140 |
1 files changed, 133 insertions, 7 deletions
diff --git a/lib/kernel/src/group.erl b/lib/kernel/src/group.erl index 4d2e31a429..c66e823a04 100644 --- a/lib/kernel/src/group.erl +++ b/lib/kernel/src/group.erl @@ -515,6 +515,27 @@ get_line1({undefined,{_A,Mode,Char},Cs,Cont,Rs}, Drv, Ls0, Encoding) Drv, Ls, Encoding) end; +%% ^R = backward search, ^S = forward search. +%% Search is tricky to implement and does a lot of back-and-forth +%% work with edlin.erl (from stdlib). Edlin takes care of writing +%% and handling lines and escape characters to get out of search, +%% whereas this module does the actual searching and appending to lines. +%% Erlang's shell wasn't exactly meant to traverse the wall between +%% line and line stack, so we at least restrict it by introducing +%% new modes: search, search_quit, search_found. These are added to +%% the regular ones (none, meta_left_sq_bracket) and handle special +%% cases of history search. +get_line1({undefined,{_A,Mode,Char},Cs,Cont,Rs}, Drv, Ls, Encoding) + when ((Mode =:= none) and (Char =:= $\^R)) -> + send_drv_reqs(Drv, Rs), + %% drop current line, move to search mode. We store the current + %% prompt ('N>') and substitute it with the search prompt. + send_drv_reqs(Drv, edlin:erase_line(Cont)), + put(search_quit_prompt, edlin:prompt(Cont)), + Pbs = prompt_bytes("(search)`': ", Encoding), + {more_chars,Ncont,Nrs} = edlin:start(Pbs, search), + send_drv_reqs(Drv, Nrs), + get_line1(edlin:edit_line1(Cs, Ncont), Drv, Ls, Encoding); get_line1({expand, Before, Cs0, Cont,Rs}, Drv, Ls0, Encoding) -> send_drv_reqs(Drv, Rs), ExpandFun = get(expand_fun), @@ -535,8 +556,59 @@ get_line1({undefined,_Char,Cs,Cont,Rs}, Drv, Ls, Encoding) -> send_drv_reqs(Drv, Rs), send_drv(Drv, beep), get_line1(edlin:edit_line(Cs, Cont), Drv, Ls, Encoding); +%% The search item was found and accepted (new line entered on the exact +%% result found) +get_line1({_What,Cont={line,_Prompt,_Chars,search_found},Rs}, Drv, Ls0, Encoding) -> + Line = edlin:current_line(Cont), + %% this may create duplicate entries. + Ls = save_line(new_stack(get_lines(Ls0)), Line), + get_line1({done, Line, "", Rs}, Drv, Ls, Encoding); +%% The search mode has been exited, but the user wants to remain in line +%% editing mode wherever that was, but editing the search result. +get_line1({What,Cont={line,_Prompt,_Chars,search_quit},Rs}, Drv, Ls, Encoding) -> + Line = edlin:current_chars(Cont), + %% Load back the old prompt with the correct line number. + case get(search_quit_prompt) of + undefined -> % should not happen. Fallback. + LsFallback = save_line(new_stack(get_lines(Ls)), Line), + get_line1({done, "\n", Line, Rs}, Drv, LsFallback, Encoding); + Prompt -> % redraw the line and keep going with the same stack position + NCont = {line,Prompt,{lists:reverse(Line),[]},none}, + send_drv_reqs(Drv, Rs), + send_drv_reqs(Drv, edlin:erase_line(Cont)), + send_drv_reqs(Drv, edlin:redraw_line(NCont)), + get_line1({What, NCont ,[]}, Drv, pad_stack(Ls), Encoding) + end; +%% Search mode is entered. +get_line1({What,{line,Prompt,{RevCmd0,_Aft},search},Rs}, + Drv, Ls0, Encoding) -> + send_drv_reqs(Drv, Rs), + %% Figure out search direction. ^S and ^R are returned through edlin + %% whenever we received a search while being already in search mode. + {Search, Ls1, RevCmd} = case RevCmd0 of + [$\^S|RevCmd1] -> + {fun search_down_stack/2, Ls0, RevCmd1}; + [$\^R|RevCmd1] -> + {fun search_up_stack/2, Ls0, RevCmd1}; + _ -> % new search, rewind stack for a proper search. + {fun search_up_stack/2, new_stack(get_lines(Ls0)), RevCmd0} + end, + Cmd = lists:reverse(RevCmd), + {Ls, NewStack} = case Search(Ls1, Cmd) of + {none, Ls2} -> + send_drv(Drv, beep), + {Ls2, {RevCmd, "': "}}; + {Line, Ls2} -> % found. Complete the output edlin couldn't have done. + send_drv_reqs(Drv, [{put_chars, Encoding, Line}]), + {Ls2, {RevCmd, "': "++Line}} + end, + Cont = {line,Prompt,NewStack,search}, + more_data(What, Cont, Drv, Ls, Encoding); get_line1({What,Cont0,Rs}, Drv, Ls, Encoding) -> send_drv_reqs(Drv, Rs), + more_data(What, Cont0, Drv, Ls, Encoding). + +more_data(What, Cont0, Drv, Ls, Encoding) -> receive {Drv,{data,Cs}} -> get_line1(edlin:edit_line(Cs, Cont0), Drv, Ls, Encoding); @@ -557,7 +629,6 @@ get_line1({What,Cont0,Rs}, Drv, Ls, Encoding) -> get_line1(edlin:edit_line([], Cont0), Drv, Ls, Encoding) end. - get_line_echo_off(Chars, Pbs, Drv) -> send_drv_reqs(Drv, [{put_chars, unicode,Pbs}]), get_line_echo_off1(edit_line(Chars,[]), Drv). @@ -632,12 +703,46 @@ save_line({stack, U, {}, []}, Line) -> save_line({stack, U, _L, D}, Line) -> {stack, U, Line, D}. -get_lines({stack, U, {}, []}) -> +get_lines(Ls) -> get_all_lines(Ls). +%get_lines({stack, U, {}, []}) -> +% U; +%get_lines({stack, U, {}, D}) -> +% tl(lists:reverse(D, U)); +%get_lines({stack, U, L, D}) -> +% get_lines({stack, U, {}, [L|D]}). + +%% There's a funny behaviour whenever the line stack doesn't have a "\n" +%% at its end -- get_lines() seemed to work on the assumption it *will* be +%% there, but the manipulations done with search history do not require it. +%% +%% It is an assumption because the function was built with either the full +%% stack being on the 'Up' side (we're on the new line) where it isn't +%% stripped. The only other case when it isn't on the 'Up' side is when +%% someone has used the up/down arrows (or ^P and ^N) to navigate lines, +%% in which case, a line with only a \n is stored at the end of the stack +%% (the \n is returned by edlin:current_line/1). +%% +%% get_all_lines works the same as get_lines, but only strips the trailing +%% character if it's a linebreak. Otherwise it's kept the same. This is +%% because traversing the stack due to search history will *not* insert +%% said empty line in the stack at the same time as other commands do, +%% and thus it should not always be stripped unless we know a new line +%% is the last entry. +get_all_lines({stack, U, {}, []}) -> U; -get_lines({stack, U, {}, D}) -> - tl(lists:reverse(D, U)); -get_lines({stack, U, L, D}) -> - get_lines({stack, U, {}, [L|D]}). +get_all_lines({stack, U, {}, D}) -> + case lists:reverse(D, U) of + ["\n"|Lines] -> Lines; + Lines -> Lines + end; +get_all_lines({stack, U, L, D}) -> + get_all_lines({stack, U, {}, [L|D]}). + +%% For the same reason as above, though, we need to expand the stack +%% in some cases to make sure we play nice with up/down arrows. We need +%% to insert newlines, but not always. +pad_stack({stack, U, L, D}) -> + {stack, U, L, D++["\n"]}. save_line_buffer("\n", Lines) -> save_line_buffer(Lines); @@ -649,6 +754,27 @@ save_line_buffer(Line, Lines) -> save_line_buffer(Lines) -> put(line_buffer, Lines). +search_up_stack(Stack, Substr) -> + case up_stack(Stack) of + {none,NewStack} -> {none,NewStack}; + {L, NewStack} -> + case string:str(L, Substr) of + 0 -> search_up_stack(NewStack, Substr); + _ -> {string:strip(L,right,$\n), NewStack} + end + end. + +search_down_stack(Stack, Substr) -> + case down_stack(Stack) of + {none,NewStack} -> {none,NewStack}; + {L, NewStack} -> + case string:str(L, Substr) of + 0 -> search_down_stack(NewStack, Substr); + _ -> {string:strip(L,right,$\n), NewStack} + end + end. + + %% This is get_line without line editing (except for backspace) and %% without echo. get_password_line(Chars, Drv) -> @@ -687,7 +813,7 @@ edit_password([$\177|Cs],[_|Chars]) ->%% is backspace enough? edit_password([Char|Cs],Chars) -> edit_password(Cs,[Char|Chars]). -%% prompt_bytes(Prompt) +%% prompt_bytes(Prompt, Encoding) %% Return a flat list of characters for the Prompt. prompt_bytes(Prompt, Encoding) -> lists:flatten(io_lib:format_prompt(Prompt, Encoding)). |