1:- module(lsp_formatter, [ file_format_edits/2,
    2                           file_formatted/2 ]).

   12:- use_module(library(readutil), [ read_file_to_string/3 ]).   13:- use_module(library(macros)).   14
   15:- include('_lsp_path_add.pl').   16:- use_module(lsp(lsp_formatter_parser), [ reified_format_for_file/2,
   17                                           emit_reified/2 ]).   18file_format_edits(Path, Edits) :-
   19    read_file_to_string(Path, OrigText, []),
   20    split_string(OrigText, "\n", "", OrigLines),
   21    file_formatted(Path, Formatted),
   22    with_output_to(string(FormattedText),
   23                   emit_reified(current_output, Formatted)),
   24    split_string(FormattedText, "\n", "", FormattedLines),
   25    create_edit_list(OrigLines, FormattedLines, Edits).
   26
   27file_formatted(Path, Formatted) :-
   28    reified_format_for_file(Path, Reified),
   29    apply_format_rules(Reified, Formatted).
   30
   31%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   32% Formatting rules
   33%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   34
   35apply_format_rules(Content, Formatted) :-
   36    phrase(formatter_rules, Content, Formatted).
   37
   38formatter_rules -->
   39    collapse_whitespace,
   40    commas_exactly_one_space,
   41    correct_indentation(_{state: [toplevel], column: 0, leading_spaces: [],
   42                          parens: []}).
   43
   44collapse_whitespace([], []) :- !.
   45collapse_whitespace([white(A), white(B)|InRest], [white(AB)|OutRest]) :- !,
   46    AB is A + B,
   47    collapse_whitespace(InRest, OutRest).
   48collapse_whitespace([In|InRest], [In|OutRest]) :-
   49    collapse_whitespace(InRest, OutRest).
   50
   51commas_exactly_one_space([], Out) => Out = [].
   52commas_exactly_one_space([white(_), comma|InRest], Out) =>
   53    commas_exactly_one_space([comma|InRest], Out).
   54commas_exactly_one_space([comma, white(_)|InRest], Out), InRest \= [comment(_)|_] =>
   55    Out = [comma, white(1)|OutRest],
   56    commas_exactly_one_space(InRest, OutRest).
   57commas_exactly_one_space([comma, Next|InRest], Out), Next \= white(_), Next \= newline =>
   58    Out = [comma, white(1), Next|OutRest],
   59    commas_exactly_one_space(InRest, OutRest).
   60commas_exactly_one_space([Other|Rest], Out) =>
   61    Out = [Other|OutRest],
   62    commas_exactly_one_space(Rest, OutRest).
   63
   64#define(toplevel_indent, 4).
   65
   66correct_indentation(_, [], []) :- !.
   67correct_indentation(State0,
   68                    [term_begin(Func, Type, Parens)|InRest],
   69                    [term_begin(Func, Type, Parens)|OutRest]) :-
   70    indent_state_top(State0, toplevel),
   71    Func = ':-', !,
   72    indent_state_push(State0, declaration, State1),
   73    update_state_column(State1, term_begin(Func, Type, Parens), State2),
   74    push_state_open_spaces(State2, InRest, State3),
   75    correct_indentation(State3, InRest, OutRest).
   76correct_indentation(State0,
   77                    [term_begin(Func, Type, Parens)|InRest],
   78                    [term_begin(Func, Type, Parens)|OutRest]) :-
   79    indent_state_top(State0, toplevel), !,
   80    update_state_column(State0, term_begin(Func, Type, Parens), State1),
   81    indent_state_push(State1, defn_head(State1.column, false), State2),
   82    push_state_open_spaces(State2, InRest, State3),
   83    correct_indentation(State3, InRest, OutRest).
   84correct_indentation(State0, [In|InRest], [In|OutRest]) :-
   85    indent_state_top(State0, toplevel),
   86    In = simple(_), !,
   87    indent_state_push(State0, defn_head_neck, State1),
   88    update_state_column(State1, In, State2),
   89    correct_indentation(State2, InRest, OutRest).
   90correct_indentation(State0,
   91                    [term_begin(Neckish, T, P)|InRest],
   92                    [term_begin(Neckish, T, P)|OutRest]) :-
   93    memberchk(Neckish, [':-', '=>', '-->']),
   94    indent_state_top(State0, defn_head_neck), !,
   95    indent_state_pop(State0, State1),
   96    indent_state_push(State1, defn_body, State2),
   97    update_state_column(State2, term_begin(Neckish, T, P), State3),
   98    push_state_open_spaces(State3, InRest, State4),
   99    correct_indentation(State4, InRest, OutRest).
  100correct_indentation(State0, [In|InRest], Out) :-
  101    once((In = term_begin('->', compound, false)
  102        ; In = term_begin('*->', compound, false)
  103        ; In = term_begin(';', compound, false))),
  104    indent_state_top(State0, defn_body_indent), !,
  105    indent_state_pop(State0, State1),
  106    paren_state_top(State1, Indent),
  107    Out = [white(Indent)|OutRest],
  108    update_state_column(State1, white(Indent), State4),
  109    correct_indentation(State4, [In|InRest], OutRest).
  110correct_indentation(State0, [newline|InRest], [newline|Out]) :- !,
  111    ( indent_state_top(State0, defn_body_indent)
  112    -> State1 = State0
  113    ; indent_state_push(State0, defn_body_indent, State1) ),
  114    update_state_column(State1, newline, State2),
  115    correct_indentation(State2, InRest, Out).
  116correct_indentation(State0, [In|InRest], Out) :-
  117    indent_state_top(State0, defn_body_indent), !,
  118    ( In = white(_)
  119    -> correct_indentation(State0, InRest, Out)
  120    ;  insert_whitespace_to_indent(State0, [In|InRest], Out) ).
  121correct_indentation(State0, [In|InRest], [In|OutRest]) :-
  122    In = term_begin(';', compound, false), !,
  123    update_alignment(State0, State1),
  124    update_state_column(State1, In, State2),

  126    copy_current_alignment(State2, CurrentAlign),
  127    indent_state_push(State2, CurrentAlign, State3),
  128    push_state_open_spaces(State3, InRest, State4),
  129    correct_indentation(State4, InRest, OutRest)

  129.
  130correct_indentation(State0, [In|InRest], [In|OutRest]) :-
  131    functor(In, Name, _Arity, _Type),
  132    atom_concat(_, '_begin', Name), !,
  133    % if we've just begun something...
  134    update_alignment(State0, State1),
  135    update_state_column(State1, In, State2),
  136    indent_state_push(State2, begin(State2.column, State1.column), State3),
  137    push_state_open_spaces(State3, InRest, State4),
  138    ( Name == parens_begin
  139    -> paren_state_push(State4, State1.column, State5)
  140    ;  State5 = State4 ),
  141    correct_indentation(State5, InRest, OutRest).
  142correct_indentation(State0, [In|InRest], [In|OutRest]) :-
  143    indent_state_top(State0, defn_head(_, _)),
  144    In = term_end(_, S), S \= toplevel, !,
  145    indent_state_pop(State0, State1),
  146    indent_state_push(State1, defn_head_neck, State2),
  147    update_state_column(State2, In, State3),
  148    pop_state_open_spaces(State3, _, State4),
  149    correct_indentation(State4, InRest, OutRest).
  150correct_indentation(State0, [In|InRest], Out) :-
  151    ending_term(In), !,
  152    indent_state_pop(State0, State1),
  153    update_state_column(State1, In, State2),
  154    pop_state_open_spaces(State2, Spaces, State3),
  155    ( In \= term_end(false, _), In \= term_end(_, toplevel), Spaces > 0
  156    -> Out = [white(Spaces), In|OutRest]
  157    ;  Out = [In|OutRest] ),
  158    ( In == parens_end
  159    -> paren_state_pop(State3, State4)
  160    ;  State3 = State4 ),
  161    correct_indentation(State4, InRest, OutRest).
  162correct_indentation(State0, [In, NextIn|InRest], Out) :-
  163    In = white(_),
  164    ending_term(NextIn), !,
  165    correct_indentation(State0, [NextIn|InRest], Out).
  166correct_indentation(State0, [In|InRest], [In|OutRest]) :-
  167    memberchk(In, [white(_), newline]), !,
  168    update_state_column(State0, In, State1),
  169    correct_indentation(State1, InRest, OutRest).
  170correct_indentation(State0, [In|InRest], [In|OutRest]) :- !,
  171    ( In \= white(_)
  172    -> update_alignment(State0, State1)
  173    ; State1 = State0 ),
  174    update_state_column(State1, In, State2),
  175    correct_indentation(State2, InRest, OutRest).
  176
  177copy_current_alignment(State, Alignment), indent_state_top(State, defn_body) =>
  178    Alignment = align(#toplevel_indent, 4).
  179copy_current_alignment(State, Alignment), indent_state_top(State, align(_, _)) =>
  180    indent_state_top(State, Alignment).
  181copy_current_alignment(State, Alignment), indent_state_top(State, begin(Col, BeganAt)) =>
  182    Alignment = begin(Col, BeganAt).
  183copy_current_alignment(State, Alignment), indent_state_top(State, defn_body_indent) =>
  184    Alignment = align(#toplevel_indent, 4).
  185copy_current_alignment(State, Alignment), indent_state_top(State, defn_head(Column, _Aligned)) =>
  186    Alignment = align(Column, Column).
  187copy_current_alignment(State, Alignment), indent_state_top(State, defn_head_neck) =>
  188    Alignment = align(#toplevel_indent, 4).
  189copy_current_alignment(State, Alignment), indent_state_top(State, declaration) =>
  190    Alignment = align(2, 2).
  191copy_current_alignment(State, Alignment) =>
  192    indent_state_top(State, Alignment).
  193
  194insert_whitespace_to_indent(State0, [In|InRest], Out) :-
  195    indent_state_pop(State0, State1),
  196    ( indent_state_top(State1, begin(_, BeganAt))
  197      % state top = begin means prev line ended with an open paren
  198    -> % so pop that off and align as if one step "back"
  199       indent_state_pop(State1, StateX),
  200       whitespace_indentation_for_state(StateX, PrevIndent),
  201       IncPrevIndent is PrevIndent + 4,
  202       indent_state_push(StateX, align(IncPrevIndent, BeganAt), State2)
  203    ; State2 = State1 ),
  204    update_alignment(State2, State3),
  205    ( ending_term(In)
  206    -> indent_for_end_term(State3, In, State4, Indent)
  207    ; whitespace_indentation_for_state(State3, Indent),
  208      State4 = State3 ),
  209    Out = [white(Indent)|OutRest],
  210    update_state_column(State4, white(Indent), State5),
  211    correct_indentation(State5, [In|InRest], OutRest).
  212
  213indent_for_end_term(State0, In, State, Indent) :-
  214    % for a paren ending a term, align a level up
  215    In = term_end(true, _), !,
  216    indent_state_pop(State0, State_),
  217    pop_state_open_spaces(State0, _, State1),
  218    push_state_open_spaces(State1, 0, State),
  219    whitespace_indentation_for_state(State_, Indent).
  220indent_for_end_term(State0, In, State, Indent) :-
  221    % for a brace ending a dict, align two levels up level up
  222    In = dict_end, !,
  223    indent_state_pop(State0, State_),
  224    indent_state_pop(State_, State__),
  225    pop_state_open_spaces(State0, _, State1),
  226    push_state_open_spaces(State1, 0, State),
  227    whitespace_indentation_for_state(State__, Indent).
  228indent_for_end_term(State0, _In, State, Indent) :-
  229    % for another ending term, align to the open
  230    % if we have alignment infomation.
  231    indent_state_top(State0, Top),
  232    Top = align(_, Indent), !,
  233    pop_state_open_spaces(State0, _, State1),
  234    push_state_open_spaces(State1, 0, State).
  235indent_for_end_term(State0, _In, State, Indent) :-
  236    % otherwise, at top-level, just pop state.
  237    indent_state_pop(State0, State_),
  238    pop_state_open_spaces(State0, _, State1),
  239    push_state_open_spaces(State1, 0, State),
  240    whitespace_indentation_for_state(State_, Indent).
  241
  242ending_term(Term) :-
  243    functor(Term, Name, _, _),
  244    atom_concat(_, '_end', Name).
  245
  246outdent_align(State, Outdented) :-
  247    whitespace_indentation_for_state(State, Indent),
  248    Outdented is Indent - 2.
  249
  250update_alignment(State0, State2) :-
  251    indent_state_top(State0, begin(Col, BeganAt)), !,
  252    indent_state_pop(State0, State1),
  253    AlignCol is max(Col, State1.column),
  254    indent_state_push(State1, align(AlignCol, BeganAt), State2).
  255update_alignment(State0, State2) :-
  256    indent_state_top(State0, defn_head(Col, false)), !,
  257    indent_state_pop(State0, State1),
  258    AlignCol is max(Col, State1.column),
  259    indent_state_push(State1, defn_head(AlignCol, true), State2).
  260update_alignment(State, State).
  261
  262whitespace_indentation_for_state(State, Indent) :-
  263    indent_state_top(State, align(Indent, _)), !.
  264whitespace_indentation_for_state(State, Indent) :-
  265    indent_state_top(State, defn_head(Indent, _)), !.
  266whitespace_indentation_for_state(State, Indent) :-
  267    get_dict(state, State, Stack),
  268    aggregate_all(count,
  269                  ( member(X, Stack),
  270                    memberchk(X, [parens_begin, braces_begin, term_begin(_, _, _)]) ),
  271                  ParensCount),
  272    ( indent_state_contains(State, defn_body)
  273    -> MoreIndent = #toplevel_indent
  274    ;  MoreIndent = 0 ),
  275    Indent is ParensCount * 2 + MoreIndent.
  276
  277indent_state_top(State, Top) :-
  278    _{state: [Top|_]} :< State.
  279
  280indent_state_contains(State, Needle) :-
  281    _{state: Stack} :< State,
  282    memberchk(Needle, Stack).
  283
  284paren_state_push(State0, NewTop, State1) :-
  285    _{parens: OldParens} :< State0,
  286    put_dict(parens, State0, [NewTop|OldParens], State1).
  287
  288paren_state_pop(State0, State1) :-
  289    _{parens: [_|Parens]} :< State0,
  290    put_dict(parens, State0, Parens, State1).
  291
  292paren_state_top(State0, Top) :-
  293    _{parens: [Top|_]} :< State0.
  294
  295indent_state_push(State0, NewTop, State1) :-
  296    _{state: Stack} :< State0,
  297    put_dict(state, State0, [NewTop|Stack], State1).
  298
  299indent_state_pop(State0, State1) :-
  300    _{state: [_|Rest]} :< State0,
  301    put_dict(state, State0, Rest, State1).
  302
  303update_state_column(State0, newline, State1) :- !,
  304    put_dict(column, State0, 0, State1).
  305update_state_column(State0, Term, State1) :-
  306    emit_reified(string(S), [Term]),
  307    string_length(S, Len),
  308    NewCol is State0.column + Len,
  309    put_dict(column, State0, NewCol, State1).
  310
  311push_state_open_spaces(State0, Next, State1) :-
  312    _{leading_spaces: PrevSpaces} :< State0,
  313    ( Next = [white(N)|_]
  314    -> put_dict(leading_spaces, State0, [N|PrevSpaces], State1)
  315    ; put_dict(leading_spaces, State0, [0|PrevSpaces], State1) ).
  316
  317pop_state_open_spaces(State0, Top, State1) :-
  318    _{leading_spaces: [Top|Spaces]} :< State0,
  319    put_dict(leading_spaces, State0, Spaces, State1).
  320
  321%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  322% Create a List of Edits from the Original and Formatted Lines
  323%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  324create_edit_list(Orig, Formatted, Edits) :-
  325    create_edit_list(0, Orig, Formatted, Edits).
  326
  327create_edit_list(_, [], [], []) :- !.
  328create_edit_list(LineNum, [Line|Lines], [], [Edit]) :- !,
  329    length(Lines, NLines),
  330    EndLine is LineNum + NLines,
  331    last([Line|Lines], LastLine),
  332    string_length(LastLine, LastLineLen),
  333    Edit = _{range: _{start: _{line: LineNum, character: 0},
  334                      end: _{line: EndLine, character: LastLineLen}},
  335             newText: ""}.
  336create_edit_list(LineNum, [], [NewLine|NewLines], [Edit|Edits]) :- !,
  337    string_length(NewLine, LenLen),
  338    Edit = _{range: _{start: _{line: LineNum, character: 0},
  339                      end: _{line: LineNum, character: LenLen}},
  340             newText: NewLine},
  341    succ(LineNum, LineNum1),
  342    create_edit_list(LineNum1, [], NewLines, Edits).
  343create_edit_list(LineNum, [OrigLine|OrigRest], [FormattedLine|FormattedRest], Edits) :-
  344    (   OrigLine \= FormattedLine  % Only create an edit if the line has changed
  345      -> string_length(OrigLine, LineLen), %TODO: what should this be?
  346         Edit = _{range: _{start: _{line: LineNum, character: 0},
  347                           end: _{line: LineNum, character: LineLen}},
  348                  newText: FormattedLine},
  349         Edits = [Edit|EditRest]
  350      ; EditRest = Edits
  351    ),
  352    succ(LineNum, LineNum1),
  353    create_edit_list(LineNum1, OrigRest, FormattedRest, EditRest).
  354
  355% lsp_formatter:file_formatted('/Users/james/Projects/prolog-lsp/prolog/format_test2.pl', Src), lsp_formatter_parser:emit_reified(user_output, Src).
  356
  357% lsp_formatter:file_formatted('/Users/james/Projects/prolog-lsp/prolog/format_test.pl', Src), setup_call_cleanup(open('/Users/james/tmp/formatted_out.pl', write, S), lsp_formatter_parser:emit_reified(S, Src), close(S)).