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使用 ConTeXt 的 \startlines 预格式化文本

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使用 ConTeXt 的 \startlines 预格式化文本

这是

我正在使用 pdf 文本提取的结果来生成源文件，以便从其 pdf 中重现（公共领域）书籍，同时尝试保留尽可能多的原始布局，尤其是换行符。到目前为止，Latex 在这方面表现良好，但我正在研究 ConTeXt 作为替代方案，部分是出于好奇。

到目前为止，我已经手动插入\linebreak（在 LaTeX 中）或\break（在 ConTeXt 中）以强制换行算法遵守原始换行符，但阅读我遇到的文档后，我\startlines 发现我不必在文本中乱放这么多垃圾。

这文档将中间论证描述为：

command that is expanded and then placed between each line and the next

但以下 MWE 的行为并不如预期：

\starttext
\setuplines[inbetween=\break]

\startlines
First line --- should be fully justified
Secondline --- should be fully justified
\stoplines

\stoptext

事实上，用一些标记测试代替中间参数表明inbetween代码只插入在段落休息：

\starttext
\setuplines[inbetween=FOO]

\startlines
First line

Secondline
\stoplines

\stoptext

另外一个值得关注的问题是，内容可能包含多个段落，因此空白行（现在附加有\break）不应强制生成新页面。

编辑1：理想情况下我应该能够使用类似的东西：

\setupindenting[yes,0.1in]
\startX
first line of first paragraph, whose end becomes a tex linebreak
second line of first paragraph, whose end becomes a tex linebreak
third line, left unjustified.

% parbreak
first line of second paragraph...
\stopX

与 HTML 标签的工作方式类似<pre>。

答案1

正如 Metafox 所解释的回答回到你之前的问题，你可以使用paragraph对齐来实现这个效果。例如，

\showframe % to visualize the page
\starttext
\setuplines[align=paragraph]

\startlines
First line --- should be fully justified
Secondline --- should be fully justified
\stoplines

\stoptext

给出

在此处输入图片描述

编辑\startlines这是获得服从的一种方法\parindent（相当假\parindent）。

\setuppapersize[A5]

\definemeasure[indent][20pt]

\setupindenting[\measure{indent},yes]

\define\ResetIndent
    {\let\Indent\FirstIndent}

\define\FirstIndent
    {\hskip\measure{indent}%
     \let\Indent\relax}

\let\Indent\FirstIndent

\setuplines
  [
    align=paragraph, 
    command={\Indent},
    inbetween={\blank\ResetIndent},
    option=packed,
  ]


\starttext
\input knuth

\startlines
Thus, I came to the conclusion that the designer of a 
new system must not only be the implementer and first 
large--scale user; the designer should also write the first 
user manual. \crlf

The separation of any of these four components would
have hurt TEX significantly. If I had not participated fully
in all these activities, literally hundreds of improvements
would never have been made, because I would never have
thought of them or perceived why they were important. \crlf

But a system cannot be successful if it is too strongly
influenced by a single person. Once the initial design is
complete and fairly robust, the real test begins as people
with many different viewpoints undertake their own exper-
iments. \crlf
\stoplines

\stoptext

一些评论：

  • 我使用\definemeasure和\measure{..}在行环境中设置缩进和使用缩进时使用相同的值。

  • option=packed确保环境内没有分页符lines。因此，您必须在单独的行环境中添加每一页。

  • 我已经手动添加到了\crlf每段的最后一行。如果您不想手动添加\crlf到每段的末尾，那么一个选项是捕获环境的内容作为缓冲区，并通过算法添加到\crlf每段的末尾。例如，参见这个例子在 wiki 中。

答案2

关注@Aditya LuaTeX参考，这里给出一个基于lua的替代解决方案：

\setuppapersize[A5]
\setupindenting[0.2in,yes]

% Create an environment that stores everything 
% between \startpreformatted and \stoppreformatted 
% in a buffer named 'preformatted'.
\def\startpreformatted
{\dostartbuffer
    [preformatted]
    [startpreformatted]
    [stoppreformatted]}

% On closing the preformatted environment, call the LuaTeX
% function preformatted(), and pass it the contents of 
% the buffer called 'preformatted'
\def\stoppreformatted
{\ctxlua
    {userdata.preformatted(buffers.getcontent('preformatted'))}}

\startluacode
userdata = userdata or {}

function userdata.isemptyline(line)
    return nil ~= string.find(line,'^ *$' )
end

function userdata.preformatted(content)
    local lines    = string.splitlines(content)
    for i=1,#lines do
        if i < #lines then
            if (not userdata.isemptyline(lines[i+1])) and (not userdata.isemptyline(lines[i])) then 
                lines[i] = lines[i]  .. "\\break"    
            end     
        -- else do something special for last line
        end  
    end

    content = table.concat(lines,'\n') 
    context(content) 
end
\stopluacode

\starttext
\startpreformatted 
Thus, I came to the conclusion that the designer of a 
new system must not only be the implementer and first 
large--scale user; the designer should also write the first 
user manual.  

The separation of any of these four components would
have hurt TEX significantly. If I had not participated fully
in all these activities, literally hundreds of improvements
would never have been made, because I would never have
thought of them or perceived why they were important. 
\stoppreformatted  

\stoptext

结果：

在此处输入图片描述

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