1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2017-2025, VU University Amsterdam 7 CWI Amsterdam 8 SWI-Prolog Solutions b.v. 9 All rights reserved. 10 11 Redistribution and use in source and binary forms, with or without 12 modification, are permitted provided that the following conditions 13 are met: 14 15 1. Redistributions of source code must retain the above copyright 16 notice, this list of conditions and the following disclaimer. 17 18 2. Redistributions in binary form must reproduce the above copyright 19 notice, this list of conditions and the following disclaimer in 20 the documentation and/or other materials provided with the 21 distribution. 22 23 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 26 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 27 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 28 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 29 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 31 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 33 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 POSSIBILITY OF SUCH DAMAGE. 35*/ 36 37:- module(editline, 38 [ el_wrap/0, % wrap user_input, etc. 39 el_wrap/4, % +Prog, +Input, +Output, +Error 40 el_wrapped/1, % +Input 41 el_unwrap/1, % +Input 42 43 el_source/2, % +Input, +File 44 el_bind/2, % +Input, +Args 45 el_addfn/4, % +Input, +Name, +Help, :Goal 46 el_cursor/2, % +Input, +Move 47 el_line/2, % +Input, -Line 48 el_insertstr/2, % +Input, +Text 49 el_deletestr/2, % +Input, +Count 50 51 el_history/2, % +Input, ?Action 52 el_history_events/2, % +Input, -Events 53 el_add_history/2, % +Input, +Line 54 el_write_history/2, % +Input, +FileName 55 el_read_history/2 % +Input, +FileName 56 ]). 57:- autoload(library(apply),[maplist/2,maplist/3]). 58:- autoload(library(lists),[reverse/2,max_list/2,append/3,member/2]). 59:- autoload(library(solution_sequences),[call_nth/2]). 60 61:- use_foreign_library(foreign(libedit4pl)). 62 63:- initialization el_wrap_if_ok. 64 65:- meta_predicate 66 el_addfn(,,,). 67 68:- multifile 69 el_setup/1, % +Input 70 prolog:complete_input/4.
81el_wrap_if_ok :- 82 \+ current_prolog_flag(console_menu_version, qt), 83 \+ current_prolog_flag(readline, readline), 84 stream_property(user_input, tty(true)), 85 !, 86 el_wrap. 87el_wrap_if_ok.
user_input
is connected to a terminal. This is the high level predicate used
for most purposes. The remainder of the library interface deals with
low level predicates that allows for applying and programming
libedit in non-standard situations.
The library is registered with ProgName set to swipl (see
el_wrap/4).
100el_wrap :- 101 el_wrapped(user_input), 102 !. 103el_wrap :- 104 stream_property(user_input, tty(true)), !, 105 el_wrap(swipl, user_input, user_output, user_error), 106 add_prolog_commands(user_input), 107 forall(el_setup(user_input), true). 108el_wrap. 109 110add_prolog_commands(Input) :- 111 el_addfn(Input, complete, 'Complete atoms and files', complete), 112 el_addfn(Input, show_completions, 'List completions', show_completions), 113 el_addfn(Input, electric, 'Indicate matching bracket', electric), 114 el_addfn(Input, isearch_history, 'Incremental search in history', 115 isearch_history), 116 el_bind(Input, ["^I", complete]), 117 el_bind(Input, ["^[?", show_completions]), 118 el_bind(Input, ["^R", isearch_history]), 119 bind_electric(Input), 120 add_paste_quoted(Input), 121 el_source(Input, _).
forall(el_setup(Input), true) after the
input stream has been wrapped, the default Prolog commands have been
added and the default user setup file has been sourced using
el_source/2. It can be used to define and bind additional commands.$HOME/.editrcbind command with the given arguments. The
example below lists the current key bindings.
?- el_bind(user_input, ['-a']).
The predicate el_bind/2 is typically used to bind commands defined using el_addfn/4. Note that the C proxy function has only the last character of the command as context to find the Prolog binding. This implies we cannot both bind e.g., "^[?" *and "?" to a Prolog function.
bind -a (see el_bind/2) and Goal is called of the
associated key-binding is activated. Goal is called as
call(:Goal, +Input, +Char, -Continue)
where Input is the input stream providing access to the editor, Char
the activating character and Continue must be instantated with one
of the known continuation codes as defined by libedit: norm,
newline, eof, arghack, refresh, refresh_beep, cursor,
redisplay, error or fatal. In addition, the following Continue
code is provided.
The registered Goal typically used el_line/2 to fetch the input line and el_cursor/2, el_insertstr/2 and/or el_deletestr/2 to manipulate the input line.
Normally el_bind/2 is used to associate the defined command with a keyboard sequence.
line(Before,
After), where Before is a string holding the text before the
cursor and After is a string holding the text after the cursor.history() from libedit. Supported actions are:
Num-String, where
Num is the event number and String is the associated string
without terminating newline.259:- multifile 260 prolog:history/2. 261 262prologhistory(Input, add(Line)) :- 263 el_add_history(Input, Line). 264prologhistory(Input, load(File)) :- 265 el_read_history(Input, File). 266prologhistory(Input, save(File)) :- 267 el_write_history(Input, File). 268prologhistory(Input, load) :- 269 el_history_events(Input, Events), 270 load_history_events(Events).
boot/history.pl276load_history_events(Events) :- 277 '$reverse'(Events, RevEvents), 278 forall('$member'(Ev, RevEvents), 279 add_event(Ev)). 280 281add_event(Num-String) :- 282 remove_dot(String, String1), 283 '$save_history_event'(Num-String1). 284 285remove_dot(String0, String) :- 286 string_concat(String, ".", String0), 287 !. 288remove_dot(String, String). 289 290 291 /******************************* 292 * ELECTRIC CARET * 293 *******************************/
299bind_electric(Input) :- 300 forall(bracket(_Open, Close), bind_code(Input, Close, electric)), 301 forall(quote(Close), bind_code(Input, Close, electric)). 302 303bind_code(Input, Code, Command) :- 304 string_codes(Key, [Code]), 305 el_bind(Input, [Key, Command]).
310electric(Input, Char, Continue) :- 311 string_codes(Str, [Char]), 312 el_insertstr(Input, Str), 313 el_line(Input, line(Before, _)), 314 ( string_codes(Before, Codes), 315 nesting(Codes, 0, Nesting), 316 reverse(Nesting, [Close|RevNesting]) 317 -> ( Close = open(_,_) % open quote 318 -> Continue = refresh 319 ; matching_open(RevNesting, Close, _, Index) 320 -> string_length(Before, Len), % Proper match 321 Move is Index-Len, 322 Continue = electric(Move, 500, refresh) 323 ; Continue = refresh_beep % Not properly nested 324 ) 325 ; Continue = refresh_beep 326 ). 327 328matching_open_index(String, Index) :- 329 string_codes(String, Codes), 330 nesting(Codes, 0, Nesting), 331 reverse(Nesting, [Close|RevNesting]), 332 matching_open(RevNesting, Close, _, Index). 333 334matching_open([Open|Rest], Close, Rest, Index) :- 335 Open = open(Index,_), 336 match(Open, Close), 337 !. 338matching_open([Close1|Rest1], Close, Rest, Index) :- 339 Close1 = close(_,_), 340 matching_open(Rest1, Close1, Rest2, _), 341 matching_open(Rest2, Close, Rest, Index). 342 343match(open(_,Open),close(_,Close)) :- 344 ( bracket(Open, Close) 345 -> true 346 ; Open == Close, 347 quote(Open) 348 ). 349 350bracket(0'(, 0')). 351bracket(0'[, 0']). 352bracket(0'{, 0'}). 353 354quote(0'\'). 355quote(0'\"). 356quote(0'\`). 357 358nesting([], _, []). 359nesting([H|T], I, Nesting) :- 360 ( bracket(H, _Close) 361 -> Nesting = [open(I,H)|Nest] 362 ; bracket(_Open, H) 363 -> Nesting = [close(I,H)|Nest] 364 ), 365 !, 366 I2 is I+1, 367 nesting(T, I2, Nest). 368nesting([0'0, 0'\'|T], I, Nesting) :- 369 !, 370 phrase(skip_code, T, T1), 371 difflist_length(T, T1, Len), 372 I2 is I+Len+2, 373 nesting(T1, I2, Nesting). 374nesting([H|T], I, Nesting) :- 375 quote(H), 376 !, 377 ( phrase(skip_quoted(H), T, T1) 378 -> difflist_length(T, T1, Len), 379 I2 is I+Len+1, 380 Nesting = [open(I,H),close(I2,H)|Nest], 381 nesting(T1, I2, Nest) 382 ; Nesting = [open(I,H)] % Open quote 383 ). 384nesting([_|T], I, Nesting) :- 385 I2 is I+1, 386 nesting(T, I2, Nesting). 387 388difflist_length(List, Tail, Len) :- 389 difflist_length(List, Tail, 0, Len). 390 391difflist_length(List, Tail, Len0, Len) :- 392 List == Tail, 393 !, 394 Len = Len0. 395difflist_length([_|List], Tail, Len0, Len) :- 396 Len1 is Len0+1, 397 difflist_length(List, Tail, Len1, Len). 398 399skip_quoted(H) --> 400 [H], 401 !. 402skip_quoted(H) --> 403 "\\", [H], 404 !, 405 skip_quoted(H). 406skip_quoted(H) --> 407 [_], 408 skip_quoted(H). 409 410skip_code --> 411 "\\", [_], 412 !. 413skip_code --> 414 [_]. 415 416 417 /******************************* 418 * COMPLETION * 419 *******************************/
complete editline function. The
predicate is called with three arguments, the first being the input
stream used to access the libedit functions and the second the
activating character. The last argument tells libedit what to do.
Consult el_set(3), EL_ADDFN for details.430:- dynamic 431 last_complete/2. 432 433complete(Input, _Char, Continue) :- 434 el_line(Input, line(Before, After)), 435 ensure_input_completion, 436 prolog:complete_input(Before, After, Delete, Completions), 437 ( Completions = [One] 438 -> string_length(Delete, Len), 439 el_deletestr(Input, Len), 440 complete_text(One, Text), 441 el_insertstr(Input, Text), 442 Continue = refresh 443 ; Completions == [] 444 -> Continue = refresh_beep 445 ; get_time(Now), 446 retract(last_complete(TLast, Before)), 447 Now - TLast < 2 448 -> nl(user_error), 449 list_alternatives(Completions), 450 Continue = redisplay 451 ; retractall(last_complete(_,_)), 452 get_time(Now), 453 asserta(last_complete(Now, Before)), 454 common_competion(Completions, Extend), 455 ( Delete == Extend 456 -> Continue = refresh_beep 457 ; string_length(Delete, Len), 458 el_deletestr(Input, Len), 459 el_insertstr(Input, Extend), 460 Continue = refresh 461 ) 462 ). 463 464:- dynamic 465 input_completion_loaded/0. 466 467ensure_input_completion :- 468 input_completion_loaded, 469 !. 470ensure_input_completion :- 471 predicate_property(prolog:complete_input(_,_,_,_), 472 number_of_clauses(N)), 473 N > 0, 474 !. 475ensure_input_completion :- 476 exists_source(library(console_input)), 477 !, 478 use_module(library(console_input), []), 479 asserta(input_completion_loaded). 480ensure_input_completion.
487show_completions(Input, _Char, Continue) :- 488 el_line(Input, line(Before, After)), 489 prolog:complete_input(Before, After, _Delete, Completions), 490 nl(user_error), 491 list_alternatives(Completions), 492 Continue = redisplay. 493 494complete_text(Text-_Comment, Text) :- !. 495complete_text(Text, Text).
501common_competion(Alternatives, Common) :- 502 maplist(atomic, Alternatives), 503 !, 504 common_prefix(Alternatives, Common). 505common_competion(Alternatives, Common) :- 506 maplist(complete_text, Alternatives, AltText), 507 !, 508 common_prefix(AltText, Common).
514common_prefix([A1|T], Common) :- 515 common_prefix_(T, A1, Common). 516 517common_prefix_([], Common, Common). 518common_prefix_([H|T], Common0, Common) :- 519 common_prefix(H, Common0, Common1), 520 common_prefix_(T, Common1, Common).
526common_prefix(A1, A2, Prefix) :- 527 sub_atom(A1, 0, _, _, A2), 528 !, 529 Prefix = A2. 530common_prefix(A1, A2, Prefix) :- 531 sub_atom(A2, 0, _, _, A1), 532 !, 533 Prefix = A1. 534common_prefix(A1, A2, Prefix) :- 535 atom_codes(A1, C1), 536 atom_codes(A2, C2), 537 list_common_prefix(C1, C2, C), 538 string_codes(Prefix, C). 539 540list_common_prefix([H|T0], [H|T1], [H|T]) :- 541 !, 542 list_common_prefix(T0, T1, T). 543list_common_prefix(_, _, []).
553list_alternatives(Alternatives) :- 554 maplist(atomic, Alternatives), 555 !, 556 length(Alternatives, Count), 557 maplist(atom_length, Alternatives, Lengths), 558 max_list(Lengths, Max), 559 tty_size(_, Cols), 560 ColW is Max+2, 561 Columns is max(1, Cols // ColW), 562 RowCount is (Count+Columns-1)//Columns, 563 length(Rows, RowCount), 564 to_matrix(Alternatives, Rows, Rows), 565 ( RowCount > 11 566 -> length(First, 10), 567 Skipped is RowCount - 10, 568 append(First, _, Rows), 569 maplist(write_row(ColW), First), 570 format(user_error, '... skipped ~D rows~n', [Skipped]) 571 ; maplist(write_row(ColW), Rows) 572 ). 573list_alternatives(Alternatives) :- 574 maplist(complete_text, Alternatives, AltText), 575 list_alternatives(AltText). 576 577to_matrix([], _, Rows) :- 578 !, 579 maplist(close_list, Rows). 580to_matrix([H|T], [RH|RT], Rows) :- 581 !, 582 add_list(RH, H), 583 to_matrix(T, RT, Rows). 584to_matrix(List, [], Rows) :- 585 to_matrix(List, Rows, Rows). 586 587add_list(Var, Elem) :- 588 var(Var), !, 589 Var = [Elem|_]. 590add_list([_|T], Elem) :- 591 add_list(T, Elem). 592 593close_list(List) :- 594 append(List, [], _), 595 !. 596 597write_row(ColW, Row) :- 598 length(Row, Columns), 599 make_format(Columns, ColW, Format), 600 format(user_error, Format, Row). 601 602make_format(N, ColW, Format) :- 603 format(string(PerCol), '~~w~~t~~~d+', [ColW]), 604 Front is N - 1, 605 length(LF, Front), 606 maplist(=(PerCol), LF), 607 append(LF, ['~w~n'], Parts), 608 atomics_to_string(Parts, Format). 609 610 611 /******************************* 612 * SEARCH * 613 *******************************/
620isearch_history(Input, _Char, Continue) :- 621 el_line(Input, line(Before, After)), 622 string_concat(Before, After, Current), 623 string_length(Current, Len), 624 search_print('', "", Current), 625 search(Input, "", Current, 1, Line), 626 el_deletestr(Input, Len), 627 el_insertstr(Input, Line), 628 Continue = redisplay. 629 630search(Input, For, Current, Nth, Line) :- 631 el_getc(Input, Next), 632 Next \== -1, 633 !, 634 search(Next, Input, For, Current, Nth, Line). 635search(_Input, _For, _Current, _Nth, ""). 636 637search(7, _Input, _, Current, _, Current) :- % C-g: abort 638 !, 639 clear_line. 640search(18, Input, For, Current, Nth, Line) :- % C-r: search previous 641 !, 642 N2 is Nth+1, 643 search_(Input, For, Current, N2, Line). 644search(19, Input, For, Current, Nth, Line) :- % C-s: search next 645 !, 646 N2 is max(1,Nth-1), 647 search_(Input, For, Current, N2, Line). 648search(127, Input, For, Current, _Nth, Line) :- % DEL/BS: shorten search 649 sub_string(For, 0, _, 1, For1), 650 !, 651 search_(Input, For1, Current, 1, Line). 652search(Char, Input, For, Current, Nth, Line) :- 653 code_type(Char, cntrl), 654 !, 655 search_end(Input, For, Current, Nth, Line), 656 el_push(Input, Char). 657search(Char, Input, For, Current, _Nth, Line) :- 658 format(string(For1), '~w~c', [For,Char]), 659 search_(Input, For1, Current, 1, Line). 660 661search_(Input, For1, Current, Nth, Line) :- 662 ( find_in_history(Input, For1, Current, Nth, Candidate) 663 -> search_print('', For1, Candidate) 664 ; search_print('failed ', For1, Current) 665 ), 666 search(Input, For1, Current, Nth, Line). 667 668search_end(Input, For, Current, Nth, Line) :- 669 ( find_in_history(Input, For, Current, Nth, Line) 670 -> true 671 ; Line = Current 672 ), 673 clear_line. 674 675find_in_history(_, "", Current, _, Current) :- 676 !. 677find_in_history(Input, For, _, Nth, Line) :- 678 el_history_events(Input, History), 679 call_nth(( member(_N-Line, History), 680 sub_string(Line, _, _, _, For) 681 ), 682 Nth), 683 !. 684 685search_print(State, Search, Current) :- 686 format(user_error, '\r(~wreverse-i-search)`~w\': ~w\e[0K', 687 [State, Search, Current]). 688 689clear_line :- 690 format(user_error, '\r\e[0K', []). 691 692 693 /******************************* 694 * PASTE QUOTED * 695 *******************************/ 696 697:- meta_predicate 698 with_quote_flags(,,). 699 700add_paste_quoted(Input) :- 701 current_prolog_flag(gui, true), 702 !, 703 el_addfn(Input, paste_quoted, 'Paste as quoted atom', paste_quoted), 704 el_bind(Input, ["^Y", paste_quoted]). 705add_paste_quoted(_).
713paste_quoted(Input, _Char, Continue) :- 714 clipboard_content(String), 715 quote_text(Input, String, Quoted), 716 el_insertstr(Input, Quoted), 717 Continue = refresh. 718 719quote_text(Input, String, Value) :- 720 el_line(Input, line(Before, _After)), 721 ( sub_string(Before, _, 1, 0, Quote) 722 -> true 723 ; Quote = "'" 724 ), 725 quote_text(Input, Quote, String, Value). 726 727quote_text(Input, "'", Text, Quoted) => 728 format(string(Quoted), '~q', [Text]), 729 el_deletestr(Input, 1). 730quote_text(Input, "\"", Text, Quoted) => 731 atom_string(Text, String), 732 with_quote_flags( 733 string, codes, 734 format(string(Quoted), '~q', [String])), 735 el_deletestr(Input, 1). 736quote_text(Input, "`", Text, Quoted) => 737 atom_string(Text, String), 738 with_quote_flags( 739 codes, string, 740 format(string(Quoted), '~q', [String])), 741 el_deletestr(Input, 1). 742quote_text(_, _, Text, Quoted) => 743 format(string(Quoted), '~q', [Text]). 744 745with_quote_flags(Double, Back, Goal) :- 746 current_prolog_flag(double_quotes, ODouble), 747 current_prolog_flag(back_quotes, OBack), 748 setup_call_cleanup( 749 ( set_prolog_flag(double_quotes, Double), 750 set_prolog_flag(back_quotes, Back) ), 751 Goal, 752 ( set_prolog_flag(double_quotes, ODouble), 753 set_prolog_flag(back_quotes, OBack) )). 754 755clipboard_content(Text) :- 756 ( current_predicate(get/3) 757 -> true 758 ; current_prolog_flag(gui, true), 759 use_module(library(pce), [get/3, in_pce_thread_sync/1]) 760 ), 761 !, 762 in_pce_thread_sync(get(@(display), paste, primary, string(Text))). 763clipboard_content("")
BSD libedit based command line editing
This library wraps the BSD libedit command line editor. The binding provides a high level API to enable command line editing on the Prolog user streams and low level predicates to apply the library on other streams and program the library. */