/* @(#) history.pl 1.4.0 (UvA SWI) Mon Jan 1 18:02:00 MET 1990 Copyright (c) 1990 Jan Wielemaker. All rights reserved. jan@swi.psy.uva.nl Purpose: implementation of history system */ :- module($history, [ read_history/6 , history_depth/1 , $clean_history/0 ]). :- dynamic history_depth/1. % read_history(+History, +Help, +DontStore, +Prompt, -Term, -Bindings) % Give a prompt using Prompt. The sequence '%w' is substituted with the % current event number. Then read a term from the input stream and perform % the history expansion. Return the expanded term and the bindings of the % variables as with read/2. % entering the term History makes read_history/5 print the history. % Help specifies the help command. % DontStore is a list of events that need not be stored. read_history(History, Help, DontStore, Prompt, Term, Bindings) :- repeat, prompt_history(Prompt), $raw_read(Raw), read_history_(History, Help, DontStore, Raw, Term, Bindings), !. read_history_(History, _, _, History, _, _) :- list_history, !, fail. read_history_(Show, Help, _, Help, _, _) :- help_history(Show, Help), !, fail. read_history_(_, _, DontStore, Raw, Term, Bindings) :- expand_history(Raw, Expanded, Changed), save_event(DontStore, Expanded), write_event(Expanded, Changed), atom_to_term(Expanded, Term, Bindings). write_event(_, false) :- !. write_event(Event, true) :- format('~w.~n', [Event]). % list_history % Write history events to the current output stream. list_history :- flag($last_event, Last, Last), history_depth_(Depth), plus(First, Depth, Last), between(First, Last, Nr), recorded($history_list, Nr/Event), format('~t~w ~8|~w.~n', [Nr, Event]), fail. list_history. $clean_history :- recorded($history_list, _, Ref), erase(Ref), fail. $clean_history :- flag($last_event, _, 0). help_history(Show, Help) :- $ttyformat('History Commands:~n'), $ttyformat(' !!. Repeat last query~n'), $ttyformat(' !nr. Repeat query numbered ~n'), $ttyformat(' !str. Repeat last query starting with ~n'), $ttyformat(' !?str. Repeat last query holding ~n'), $ttyformat(' ^old^new. Substitute into of last query~n'), $ttyformat(' !nr^old^new. Substitute in query numbered ~n'), $ttyformat(' !str^old^new. Substitute in query starting with ~n'), $ttyformat(' !?str^old^new. Substitute in query holding ~n'), $ttyformat(' ~w.~21|Show history list~n', [Show]), $ttyformat(' ~w.~21|Show this list~n', [Help]). % prompt_history(+Prompt) % Give prompt, substituting '%w' by the event number. prompt_history(Prompt) :- flag($last_event, Old, Old), succ(Old, This), name(Prompt, SP), name(This, ST), substitute("%w", ST, SP, String), $ttyformat('~s', [String]), ttyflush. % save_event(+Event) % Save Event in the history system. Remove possibly outdated events. save_event(Dont, Event) :- memberchk(Event, Dont), !. save_event(_, Event) :- flag($last_event, Old, Old), succ(Old, New), flag($last_event, _, New), recorda($history_list, New/Event), history_depth_(Depth), remove_history(New, Depth). remove_history(New, Depth) :- New - Depth =< 0, !. remove_history(New, Depth) :- Remove is New - Depth, recorded($history_list, Remove/_, Ref), !, erase(Ref). remove_history(_, _). % history_depth_(-Depth) % Define the depth to which to keep the history. history_depth_(N) :- history_depth(N), !. history_depth_(15). % expand_history(+Raw, -Expanded) % Expand Raw using the available history list. Expandations performed % are: % % ^old^new % Substitute % !match % Last event starting % !?match % Last event matching % !n % Event nr. % !spec^old^new % substitute in last event % !! % last event % % Note: the first character after a '!' should be a letter or number to % avoid problems with the cut. expand_history(Raw, Expanded, Changed) :- name(Raw, RawString), expand_history2(RawString, ExpandedString, Changed), name(Expanded, ExpandedString), !. expand_history2([0'^|Rest], Expanded, true) :- !, get_last_event(Last), old_new(Rest, Old, New, []), substitute(Old, New, Last, Expanded). expand_history2(String, Expanded, Changed) :- expand_history3(String, Expanded, Changed). expand_history3([0'!, C|Rest], [0'!|Expanded], Changed) :- not_event_char(C), !, expand_history3([C|Rest], Expanded, Changed). expand_history3([0'!|Rest], Expanded, true) :- !, match_event(Rest, Event, NewRest), append(Event, RestExpanded, Expanded), !, expand_history3(NewRest, RestExpanded, _). expand_history3([H|T], [H|R], Changed) :- !, expand_history3(T, R, Changed). expand_history3([], [], false). % old_new(+Spec, -Old, -New, -Left) % Takes Spec as a substitute specification without the first '^' and % returns the Old and New substitute patterns as well s possible text % left. old_new([0'^|Rest], [], New, Left) :- !, new(Rest, New, Left). old_new([H|Rest], [H|Old], New, Left) :- old_new(Rest, Old, New, Left). new([], [], []) :- !. new([0'^|Left], [], Left) :- !. new([H|T], [H|New], Left) :- new(T, New, Left). % get_last_event(-String) % return last event typed as a string get_last_event(Event) :- recorded($history_list, _/Atom), name(Atom, Event), !. get_last_event(_) :- $ttyformat('! No such event~n'), fail. % substitute(+Old, +New, +String, -Substituted) % substitute first occurence of Old in String by New substitute(Old, New, String, Substituted) :- append(Head, OldAndTail, String), append(Old, Tail, OldAndTail), !, append(Head, New, HeadAndNew), append(HeadAndNew, Tail, Substituted), !. substitute(_, _, _, _) :- $ttyformat('! bad substitution~n'), fail. % match_event(+Spec, -Event, -Rest) % Use Spec as a specification of and event and return the event as Event % and what is left of Spec as Rest. match_event(Spec, Event, Rest) :- find_event(Spec, RawEvent, Rest0), !, substitute_event(Rest0, RawEvent, Event, Rest). match_event(_, _, _) :- $ttyformat('! No such event~n'), fail. substitute_event([0'^|Spec], RawEvent, Event, Rest) :- !, old_new(Spec, Old, New, Rest), substitute(Old, New, RawEvent, Event). substitute_event(Rest, Event, Event, Rest). alpha(C) :- between(0'a, 0'z, C). alpha(C) :- between(0'A, 0'Z, C). alpha(0'_). digit(C) :- between(0'0, 0'9, C). alpha_digit(C) :- alpha(C). alpha_digit(C) :- digit(C). not_event_char(C) :- alpha_digit(C), !, fail. not_event_char(0'?) :- !, fail. not_event_char(0'!) :- !, fail. not_event_char(_). find_event([0'?|Rest], Event, Left) :- !, take_string(Rest, String, Left), matching_event(substring, String, Event). find_event([0'!|Left], Event, Left) :- !, get_last_event(Event). find_event([N|Rest], Event, Left) :- digit(N), !, take_number([N|Rest], String, Left), name(Number, String), recorded($history_list, Number/Atom), name(Atom, Event). find_event(Spec, Event, Left) :- take_string(Spec, String, Left), matching_event(prefix, String, Event). take_string([C|Rest], [C|String], Left) :- alpha_digit(C), !, take_string(Rest, String, Left). take_string([C|Rest], [], [C|Rest]) :- !. take_string([], [], []). take_number([C|Rest], [C|String], Left) :- digit(C), !, take_string(Rest, String, Left). take_number([C|Rest], [], [C|Rest]) :- !. take_number([], [], []). % matching_event(+Where, +String, -Event) % Return first event with prefix String as a Prolog string. matching_event(prefix, String, Event) :- recorded($history_list, _/AtomEvent), name(AtomEvent, Event), append(String, _, Event), !. matching_event(substring, String, Event) :- recorded($history_list, _/AtomEvent), name(AtomEvent, Event), append(_, MatchAndTail, Event), append(String, _, MatchAndTail), !.