/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: http://www.swi-prolog.org Copyright (c) 2018-2020, CWI, Amsterdam All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(html_text, [ html_text/1, % +FileName html_text/2 % +FileName, Options ]). :- use_module(library(debug),[debug/3]). :- autoload(library(ansi_term),[ansi_format/3]). :- autoload(library(apply),[foldl/4,maplist/3,maplist/2]). :- autoload(library(error),[must_be/2]). :- autoload(library(lists), [ append/3, list_to_set/2, reverse/2, delete/3, sum_list/2, nth1/3, max_list/2 ]). :- autoload(library(option),[select_option/4,merge_options/3,option/3]). :- autoload(library(sgml),[xml_is_dom/1,load_html/3]). :- autoload(library(lynx/format),[format_paragraph/2,trim_line/2]). :- autoload(library(lynx/html_style), [ element_css/3, css_block_options/5, css_inline_options/3, attrs_classes/2, style_css_attrs/2 ]). :- predicate_options(html_text/2, 2, [ margin_left(integer), margin_right(integer), width(integer), text_align(oneof([justify, left])) ]). /** Render HTML as plain text This module renders HTML markup as plain text, just like the open _lynx_ program does. It is (as yet), limited to and spacialized for dealing with the SWI-Prolog documentation. This library first of all supports help/1. */ %! html_text(+Input) is det. %! html_text(+Input, +Options) is det. % % Render HTML from Input to `current_output`. Input is either an HTML % DOM or a valid input for load_html/3. Options defined are: % % - margin_left(+N) % - margin_right(+N) % Initial margins. % - width(+N) % Total preceived line width. % - text_align(+Align) % One of `justify` or `left`. Default is `justify`. html_text(Input) :- html_text(Input, []). html_text(Input, Options) :- ( xml_is_dom(Input) -> DOM = Input ; load_html(Input, DOM, Options) ), default_state(State0), state_options(Options, State0, State), init_nl, format_dom(DOM, State). state_options([], State, State). state_options([H|T], State0, State) :- H =.. [Key,Value], ( fmt_option(Key, Type, _Default) -> must_be(Type, Value), State1 = State0.put(Key,Value) ; State1 = State0 ), state_options(T, State1, State). fmt_option(margin_left, integer, 0). fmt_option(margin_right, integer, 0). fmt_option(text_align, oneof([justify, left]), justify). fmt_option(width, between(10,1000), 72). default_state(State) :- findall(Key-Value, fmt_option(Key, _, Value), Pairs), dict_pairs(Dict, _, Pairs), State = Dict.put(_{ style:[], list:[]}). %! format_dom(+DOM, +State) is det. % % Format the given HTML DOM to `current_output` according to State. format_dom([], _) :- !. format_dom([H|T], State) :- format_dom(H, State), !, format_dom(T, State). format_dom(Content, State) :- Content = [H0|_], \+ is_block_element(H0), !, ( append(Inline, [H|T], Content), is_block_element(H) -> true ; Inline = Content ), format_dom(element(p, [], Inline), State), format_dom([H|T], State). format_dom(element(html, _, Content), State) :- !, format_dom(Content, State). format_dom(element(head, _, _), _) :- !. format_dom(element(body, _, Content), State) :- !, format_dom(Content, State). format_dom(element(E, Attrs, Content), State) :- !, ( format_element(E, Attrs, Content, State) -> true ; debug(format(html), 'Skipped block element ~q', [E]) ). format_element(pre, Attrs, [Content], State) :- !, block_element(pre, Attrs, Top-Bottom, BlockAttrs, Style), update_style(Style, State, State1), ask_nl(Top), emit_code(Content, BlockAttrs, State1), ask_nl(Bottom). format_element(table, Attrs, Content, State) :- !, block_element(table, Attrs, Top-Bottom, BlockAttrs, Style), update_style(Style, State, State1), state_par_properties(State1, BlockAttrs, BlockOptions), ask_nl(Top), emit_nl, format_table(Content, Attrs, BlockOptions, State1), ask_nl(Bottom). format_element(hr, Attrs, _, State) :- !, block_element(hr, Attrs, Top-Bottom, BlockAttrs, Style), update_style(Style, State, State1), state_par_properties(State1, BlockAttrs, BlockOptions), ask_nl(Top), emit_nl, emit_hr(Attrs, BlockOptions, State1), ask_nl(Bottom). format_element(Elem, Attrs, Content, State) :- block_element(Elem, Attrs, Top-Bottom, BlockAttrs, Style), !, update_style(Style, State, State1), block_words(Content, SubBlocks, Words, State1), ( Words == [] -> true ; ask_nl(Top), emit_block(Words, BlockAttrs, State1), ask_nl(Bottom) ), ( SubBlocks \== [] -> update_state_par_properties(BlockAttrs, State1, State2), format_dom(SubBlocks, State2) ; true ). format_element(Elem, Attrs, Content, State) :- list_element(Elem, Attrs, Top-Bottom, State, State1), !, open_list(Elem, State1, State2), ask_nl(Top), format_list(Content, Elem, 1, State2), ask_nl(Bottom). format_element(Elem, Attrs, Content, State) :- format_list_element(element(Elem, Attrs, Content), none, 0, State). %! block_element(+El, +Attrs, -Margin, -ParOPtions, -Style) % % Describe a block element block_element(El, Attrs, Margins, ParOptions, Style) :- block_element(El, Margins0, ParOptions0, Style0), ( nonvar(Attrs), element_css(El, Attrs, CSS) -> css_block_options(CSS, Margins0, Margins, ParOptions, Style1), append(Style1, Style0, Style2), list_to_set(Style2, Style) ; Margins = Margins0, ParOptions = ParOptions0, Style = Style0 ). block_element(p, 1-2, [], []). block_element(div, 1-1, [], []). block_element(hr, 1-1, [], []). block_element(h1, 2-2, [], [bold]). block_element(h2, 2-2, [], [bold]). block_element(h3, 2-2, [], [bold]). block_element(h4, 2-2, [], [bold]). block_element(pre, 2-2, [], []). block_element(blockquote, 2-2, [margin_left(4), margin_right(4)], []). block_element(table, 2-2, [], []). list_element(ul, _, Margins, State0, State) :- margins(4, 4, State0, State), list_level_margins(State, Margins). list_element(ol, _, Margins, State0, State) :- margins(4, 4, State0, State), list_level_margins(State, Margins). list_element(dl, _, 2-2, State, State). list_element(ul). list_element(ol). list_element(dl). list_level_margins(State, 2-2) :- nonvar(State), State.get(list) == [], !. list_level_margins(_, 0-0). format_list([], _, _, _). format_list([H|T], Type, Nth, State) :- format_list_element(H, Type, Nth, State), ( T == [] -> true ; Nth1 is Nth + 1, format_list(T, Type, Nth1, State) ). format_list_element(element(LE, Attrs, Content), Type, Nth, State) :- setup_list_element(LE, Attrs, Type, Nth, ListParProps, State, State1), block_words(Content, Blocks, Words, State1), emit_block(Words, ListParProps, State1), ( Blocks \== [] -> ask_nl(2), % empty line before next par update_state_par_properties(ListParProps, State1, State2), format_dom(Blocks, State2) ; true ). setup_list_element(li, _Attrs, _Type, Nth, ListParProps, State, State) :- list_par_properties(State.list, Nth, ListParProps). setup_list_element(dt, _Attrs, _Type, _Nth, [], State, State2) :- margins(0, 0, State, State1), update_style([bold], State1, State2). setup_list_element(dd, _Attrs, _Type, _Nth, [], State, State1) :- margins(4, 0, State, State1). list_item_element(li). list_item_element(dt). list_item_element(dd). list_par_properties([ul|_More], _, [bullet('\u2022')]). list_par_properties([ol|_More], N, [bullet(N)]). %! block_words(+Content, -RestContent, -Words, +State) % % Turn Content into a list of words with attributes and spaces. block_words(Content, RC, Words, State) :- phrase(bwords(Content, RC, State), Words0), join_whitespace(Words0, Words1), trim_line(Words1, Words). bwords([], [], _) --> !. bwords([H|T], Rest, _State) --> { var(Rest), is_block_element(H), !, Rest = [H|T] }. bwords([H|T], Rest, State) --> !, bwordsel(H, State), bwords(T, Rest, State). is_block_element(element(E,_,_)) :- ( block_element(E, _, _, _) ; list_element(E) ; list_item_element(E) ), debug(format(html), 'Found block ~q', [E]), !. bwordsel(element(Elem, Attrs, Content), State) --> { styled_inline(Elem, Attrs, Margins, Style), !, update_style(Style, State, State1) }, left_margin(Margins), bwords(Content, [], State1), right_margin(Margins). bwordsel(element(br, _, _), _State) --> [br([])]. bwordsel(CDATA, State) --> { atomic(CDATA), !, split_string(CDATA, " \n\t\r", "", Words) }, words(Words, State). bwordsel(element(Elem, _Attrs, _Content), _State) --> { debug(format(html), 'Skipped inline element ~q', [Elem]) }. left_margin(0-_) --> !. left_margin(N-_) --> [b(N,_)]. right_margin(_-0) --> !. right_margin(_-N) --> [b(N,_)]. styled_inline(El, Attrs, Margins, Style) :- styled_inline(El, Style0), ( nonvar(Attrs), element_css(El, Attrs, CSS) -> css_inline_options(CSS, Margins, Style1), append(Style1, Style0, Style2), list_to_set(Style2, Style) ; Style = Style0 ). styled_inline(b, [bold]). styled_inline(strong, [bold]). styled_inline(em, [bold]). styled_inline(span, []). styled_inline(i, [underline]). styled_inline(a, [underline]). styled_inline(var, []). styled_inline(code, []). %! words(+Tokens, +State)// % % Generate a list of w(Word,Len,Attrs) and b(Len,_) terms for words % and (breakable) white space. words([], _) --> []. words([""|T0], State) --> !, { skip_leading_spaces(T0, T) }, space, words(T, State). words([H|T], State) --> word(H, State), ( {T==[]} -> [] ; { skip_leading_spaces(T, T1) }, space, words(T1, State) ). skip_leading_spaces([""|T0], T) :- !, skip_leading_spaces(T0, T). skip_leading_spaces(L, L). word(W, State) --> { string_length(W, Len), ( Style = State.get(style) -> true ; Style = [] ) }, [w(W, Len, Style)]. space --> [b(1,_)]. %! join_whitespace(Elements, Joined) % % Join consequtive space elements into a single white space element. join_whitespace([], []). join_whitespace([H0|T0], [H|T]) :- join_whitespace(H0, H, T0, T1), !, join_whitespace(T1, T). join_whitespace([H|T0], [H|T]) :- join_whitespace(T0, T). join_whitespace(b(Len0,_), b(Len,_), T0, T) :- take_whitespace(T0, T, Len0, Len). take_whitespace([b(Len1,_)|T0], T, Len0, Len) :- !, Len2 is max(Len1,Len0), take_whitespace(T0, T, Len2, Len). take_whitespace(L, L, Len, Len). /******************************* * STATE MANAGEMENT * *******************************/ %! update_style(+Style:list, +State0, -State) % % Add Style to the current state. update_style([], State, State) :- !. update_style(Extra, State0, State) :- ( get_dict(style, State0, Style0, State, Style) -> add_style(Extra, Style0, Style) ; add_style(Extra, [], Style), put_dict(style, State0, Style, State) ). add_style(Extra, Style0, Style) :- reverse(Extra, RevExtra), foldl(add1_style, RevExtra, Style0, Style). %! add1_style(+New, +Style0, -Style) is det. % % Modify the current text style. add1_style(New, Style0, Style) :- ( style_overrides(New, Add, Overrides) -> delete_all(Overrides, Style0, Style1), append(Add, Style1, Style) ; Style = [New|Style0] ). delete_all([], List, List). delete_all([H|T], List0, List) :- delete(List0, H, List1), delete_all(T, List1, List). style_overrides(normal, [], [bold]). style_overrides(fg(C), [fg(C)], [fg(_), hfg(_)]). style_overrides(bg(C), [bg(C)], [bg(_), hbg(_)]). style_overrides(underline(false), [], [underline]). margins(Left, Right, State0, State) :- _{ margin_left:ML0, margin_right:MR0 } >:< State0, ML is ML0 + Left, MR is MR0 + Right, State = State0.put(_{margin_left:ML, margin_right:MR}). open_list(Type, State0, State) :- get_dict(list, State0, Lists, State, [Type|Lists]). update_state_par_properties([], State, State). update_state_par_properties([H|T], State0, State) :- H =.. [ Key, Value ], State1 = State0.put(Key,Value), update_state_par_properties(T, State1, State). %! state_par_properties(+State, -ParProps) % % Get the paragraph shape properties from State. Eventually these two % should be merged! state_par_properties(State, Props) :- Props0 = [ margin_left(LM), margin_right(RM), text_align(TA), width(W), pad(Pad) ], _{margin_left:LM, margin_right:RM, text_align:TA, width:W, pad:Pad} >:< State, filled_par_props(Props0, Props). filled_par_props([], []). filled_par_props([H|T0], [H|T]) :- arg(1, H, A), nonvar(A), !, filled_par_props(T0, T). filled_par_props([_|T0], T) :- filled_par_props(T0, T). state_par_properties(State, Options, BlockOptions) :- state_par_properties(State, Options0), foldl(merge_par_option, Options, Options0, BlockOptions). merge_par_option(margin_left(ML0), Options0, [margin_left(ML)|Options1]) :- !, select_option(margin_left(ML1), Options0, Options1, 0), ML is ML0+ML1. merge_par_option(margin_right(MR0), Options0, [margin_right(MR)|Options1]) :- !, select_option(margin_right(MR1), Options0, Options1, 0), MR is MR0+MR1. merge_par_option(Opt, Options0, Options) :- merge_options([Opt], Options0, Options). %! emit_block(+Words, +Options, +State) is det. % % Format a block given Words inline elements, Options and State. Calls % format_paragraph/2 after finalizing the paragraph shape and using % the newline logic. emit_block([], _, _) :- !. emit_block(Words, Options, State) :- state_par_properties(State, Options, BlockOptions), use_current_position(BlockOptions, BlockOptions1), ask_nl(1), emit_nl, format_paragraph(Words, BlockOptions1), ask_nl(1). use_current_position(Options0, Options) :- nb_current(nl_pending, start), line_position(current_output, Pos), Pos > 0, !, Hang is -Pos, Options = [hang(Hang)|Options0]. use_current_position(Options, Options). %! init_nl is det. %! init_nl(-State) is det. %! exit_nl(+State) is det. % % Initialize/finalize the newline logic. init_nl :- nb_setval(nl_pending, start). init_nl(Old) :- ( nb_current(nl_pending, Old) -> true ; Old = [] ), nb_setval(nl_pending, start). exit_nl(Old) :- nb_setval(nl_pending, Old). ask_nl(N) :- ( nb_current(nl_pending, N0) -> ( N0 == start -> true ; integer(N0) -> N1 is max(N0, N), nb_setval(nl_pending, N1) ; nb_setval(nl_pending, N) ) ; nb_setval(nl_pending, N) ). emit_nl :- ( nb_current(nl_pending, N), integer(N) -> forall(between(1,N,_), nl) ; true ), nb_setval(nl_pending, 0). /******************************* * PRE * *******************************/ %! emit_code(+Content, +BlockAttrs, +State) emit_code(Content, BlockAttrs, State) :- Style = State.style, split_string(Content, "\n", "", Lines), option(margin_left(LM0), BlockAttrs, 4), LM is LM0+State.margin_left, ask_nl(1), emit_nl, emit_code_lines(Lines, 1, LM, Style), ask_nl(1). emit_code_lines([], _, _, _). emit_code_lines([H|T], LineNo, LM, Style) :- emit_code_line(H, LineNo, LM, Style), LineNo1 is LineNo + 1, emit_code_lines(T, LineNo1, LM, Style). emit_code_line(Line, _LineNo, LM, Style) :- emit_nl, emit_indent(LM), ( Style == [] -> write(Line) ; ansi_format(Style, '~s', [Line]) ), ask_nl(1). emit_indent(N) :- forall(between(1, N, _), put_char(' ')). /******************************* * TABLES * *******************************/ %! format_table(+Content, +Attrs, +BlockAttrs, +State) is det. format_table(Content, Attrs, BlockAttrs, State) :- tty_state(TTY), option(margin_left(ML), BlockAttrs, 0), option(margin_right(MR), BlockAttrs, 0), MaxTableWidth is State.width - ML - MR, table_cell_state(Attrs, State, CellState), phrase(rows(Content), Rows), columns(Rows, Columns), maplist(auto_column_width(CellState.put(tty,false)), Columns, Widths), column_widths(Widths, MaxTableWidth, ColWidths), maplist(format_row(ColWidths, CellState.put(tty,TTY), ML), Rows). tty_state(TTY) :- stream_property(current_output, tty(true)), !, TTY = true. tty_state(false). %! column_widths(+AutoWidths, +MaxTableWidth, -Widths) is det. % % Establish the widths of the columns. AutoWidths is a list of widths % for each of the columns if no folding is applied. column_widths(Widths, MaxTableWidth, Widths) :- sum_list(Widths, AutoWidth), AutoWidth =< MaxTableWidth, !. column_widths(AutoWidths, MaxTableWidth, Widths) :- sort(0, >=, AutoWidths, Sorted), append(Wrapped, Keep, Sorted), sum_list(Keep, KeepWidth), KeepWidth < MaxTableWidth/2, length(Wrapped, NWrapped), WideWidth is round((MaxTableWidth-KeepWidth)/NWrapped), ( [KeepW|_] = Keep -> true ; KeepW = 0 ), !, maplist(truncate_column(KeepW,WideWidth), AutoWidths, Widths). truncate_column(Keep, WideWidth, AutoWidth, Width) :- ( AutoWidth =< Keep -> Width = AutoWidth ; Width = WideWidth ). table_cell_state(Attrs, State, CellState) :- ( element_css(table, Attrs, CSS) -> true ; CSS = [] ), option(padding_left(PL), CSS, 1), option(padding_right(PR), CSS, 1), CellState = State.put(_{margin_left:PL, margin_right:PR}). %! rows(+Content, -Rows) is det. rows([]) --> []. rows([H|T]) --> rows(H), rows(T). rows([element(tbody,_,Content)|T]) --> rows(Content), rows(T). rows([element(tr,Attrs,Columns)|T]) --> [row(Columns, Attrs)], rows(T). %! columns(+Rows, -Columns) is det. % % Transpose the table, filling missing columns with an empty `td` % element as needed. columns(Rows, Columns) :- columns(Rows, 1, Columns). columns(Rows, I, Columns) :- maplist(row_column(I, Found), Rows, H), ( Found == true -> Columns = [H|T], I2 is I + 1, columns(Rows, I2, T) ; Columns = [] ). row_column(I, Found, row(Columns, _Attrs), Cell) :- ( nth1(I, Columns, Cell) -> Found = true ; Cell = element(td,[],[]) ). auto_column_width(State, Col, Width) :- maplist(auto_cell_width(State), Col, Widths), max_list(Widths, Width). auto_cell_width(State, Cell, Width) :- cell_colspan(Cell, 1), !, format_cell_to_string(Cell, 1_000, State, String), split_string(String, "\n", "", Lines), maplist(string_length, Lines, LineW), max_list(LineW, Width0), Width is Width0 + State.margin_right. auto_cell_width(_, _, 0). %! format_row(+ColWidths, +State, +MarginLeft, +Row) % % Format a single row. format_row(ColWidths, State, MarginLeft, Row) :- hrule(Row, ColWidths, MarginLeft), format_cells(ColWidths, CWSpanned, 1, Row, State, Cells), format_row_lines(1, CWSpanned, Cells, MarginLeft). hrule(row(_, Attrs), ColWidths, MarginLeft) :- attrs_classes(Attrs, Classes), memberchk(hline, Classes), !, sum_list(ColWidths, RuleLen), format('~N~t~*|~`-t~*+', [MarginLeft, RuleLen]). hrule(_, _, _). format_row_lines(LineNo, Widths, Cells, MarginLeft) :- nth_row_line(Widths, 1, LineNo, Cells, CellLines, Found), ( Found == true -> emit_nl, emit_indent(MarginLeft), maplist(emit_cell_line, CellLines), ask_nl(1), LineNo1 is LineNo + 1, format_row_lines(LineNo1, Widths, Cells, MarginLeft) ; true ). emit_cell_line(Line-Pad) :- write(Line), forall(between(1,Pad,_), put_char(' ')). nth_row_line([], _, _, _, [], _). nth_row_line([ColW|CWT], CellNo, LineNo, Cells, [CellLine-Pad|ColLines], Found) :- nth1(CellNo, Cells, CellLines), ( nth1(LineNo, CellLines, CellLine) -> Found = true, Pad = 0 ; CellLine = '', Pad = ColW ), CellNo1 is CellNo + 1, nth_row_line(CWT, CellNo1, LineNo, Cells, ColLines, Found). %! format_cells(+ColWidths, -CWSpanned, +Col0, +Row, +State, -Cells) % % Format the cells for Row. The resulting Cells list is a list of % cells, where each cell is a list of strings, each representing a % line. format_cells([], [], _, _, _, []) :- !. format_cells(CWidths, [HW|TW], Column, Row, State, [HC|TC]) :- Row = row(Columns, _Attrs), nth1(Column, Columns, Cell), cell_colspan(Cell, CWidths, HW, TW0), cell_align(Cell, Align), format_cell_to_string(Cell, HW, State.put(_{pad:' ', text_align:Align}), String), split_string(String, "\n", "", HC), Column1 is Column+1, format_cells(TW0, TW, Column1, Row, State, TC). cell_colspan(Cell, CWidths, HW, TW) :- cell_colspan(Cell, Span), length(SpanW, Span), append(SpanW, TW, CWidths), sum_list(SpanW, HW). cell_colspan(element(_,Attrs,_), Span) :- ( memberchk(colspan=SpanA, Attrs), atom_number(SpanA, SpanN) -> Span = SpanN ; Span = 1 ). %! cell_align(+Cell, -Align) is det. % % Determine the cell alignment. Currently supports the (deprecated) % HTML4 `align=Align` possibility and very naively parsed CSS % ``text-align:center``, etc. cell_align(element(_,Attrs,_), Align) :- ( memberchk(align=AlignA, Attrs) -> Align = AlignA ; memberchk(style=Style, Attrs), style_css_attrs(Style, Props), memberchk('text-align'(AlignA), Props) -> Align = AlignA ; Align = left ). %! format_cell_to_string(+Cell, +ColWidth, +State, -String) is det. % % Format Cell to a String, given the state and column width. format_cell_to_string(element(_,_,[]), ColWidth, State, String) :- Pad = State.get(pad), !, length(Chars, ColWidth), maplist(=(Pad), Chars), atomics_to_string(Chars, String). format_cell_to_string(Cell, ColWidth, State, String) :- setup_call_cleanup( init_nl(NlState), with_output_to( string(String), format_cell(Cell, ColWidth, State)), exit_nl(NlState)). format_cell(element(E, _Attrs, Content), ColWidth, State) :- set_stream(current_output, tty(State.tty)), cell_element(E, Style), update_style(Style, State.put(width, ColWidth), CellState), block_words(Content, Blocks, Words, CellState), emit_block(Words, [], CellState), ( Blocks \== [] -> format_dom(Blocks, CellState) ; true ). cell_element(td, [normal]). cell_element(th, [bold]). %! emit_hr(+Attrs, +BlockOptions, +State) % % Emit a horizontal rule. emit_hr(_Attrs, BlockAttrs, State) :- option(margin_left(ML), BlockAttrs, 0), option(margin_right(MR), BlockAttrs, 0), RuleWidth is State.width - ML - MR, Style = State.style, emit_indent(ML), ( Style == [] -> format('~|~*t~*+', [0'-, RuleWidth]) ; ansi_format(Style, '~|~*t~*+', [0'-, RuleWidth]) ).