On 30 Apr 2020, at 22:54, Wolfgang Schuster wolfgang.schuster.lists@gmail.com wrote:

Gerben Wierda schrieb am 30.04.2020 um 22:47:

...

In normal TeX, when I type Aap\\Aap I get something like Aap Aap But inside a \framed[align=]{} the empty line disappears. How do I get it back? Minimal example: \starttext Testing\\Testing \page \framed[align=flushleft]{Testing\\Testing} \stoptext

Use \blank

Too happy too soon. And I recall I ran into this earlier a while ago in another setting ago. But I thought of a solution.

Background:

I am automatically converting input from an XML file to METAPOST/ConTeXt. The input may contain one or more newlines.The text must end up in \framed[align=??, width=??] to be typeset.

I use lua to convert and make it safe to pass to METAPOST as a string argument that METAPOST can pass on to textext(), using the following function:

function doubleQuotableEscapedConTeXtString( str) local rep = lpeg.replacer { { '\n', '\blank ' }, { '{', '{\textbraceleft}' }, { '}', '{\textbraceright}' }, { '#', '{\texthash}' }, { '$', '{\textdollar}' }, { '&', '{\textampersand}' }, { '%', '{\textpercent}' }, { '\','{\textbackslash}' }, { '|', '{\textbar}' }, { '_', '{\textunderscore}' }, { '~', '{\textasciitilde}' }, { '^', '{\textasciicircum}' }, { '"', ""&ditto&"" }, } return rep:match(str) end

Where it now says \blank, it used to say \\.

Problem

\\ gets me what I want if there is one \n (it turns into one new line), but with two \n in succession it still gets me only a single ’newline' \blank gets me what I want if there are multiple newlines, but gets me an extra empty line when I only want ’next line’ and multiple \blanks do not work

But I found the solution by using \strut\ instead of \blank. In the above table:

{ ‘\n', ‘\strut\\' },

This fools ConTeXt in thinking there actually is something on that line and so multiple \ will work.

G

On 1 May 2020, at 09:38, Hans Hagen j.hagen@xs4all.nl wrote:

On 5/1/2020 1:44 AM, Gerben Wierda wrote:

...

{ ‘\n', ‘\strut\\' },

often a \zwj or \zwno also works ok (has zero dimensions, contraty to strut; you could also try \crlf

I tried \crlf{} and that worked too (the “{}” because I do not know what comes after even if I think any whitespace is eaten and to influence any catcode trickery, just feels it is more robust than a space).

Hans, an additional question about lmtx’s XML interface. As I want the TeX special characters to be able to be part of a label, I replace all of them. That works. But what if I would like a way to introduce TeX commands again by using some other UTF8 character, would there be a character that curvies the pass through lmtx, can be used in a lua table so that I can (in a preferred order) get unescaped characters passed that flow?

E.g. code a \ as some weird UTF8 character in the XML file, and in that table I use

local rep = lpeg.replacer { { '\n', '\crlf{}' }, { '{', '{\textbraceleft}' }, { '}', '{\textbraceright}' }, { '#', '{\texthash}' }, { '$', '{\textdollar}' }, { '&', '{\textampersand}' }, { '%', '{\textpercent}' }, { '\','{\textbackslash}' }, { '|', '{\textbar}' }, { '_', '{\textunderscore}' }, { '~', '{\textasciitilde}' }, { '^', '{\textasciicircum}' }, { '"', ""&ditto&"" }, }

code it back to a \ ? E.g. something like

{ ‘\U{XXX}', '' },

Hans

---

                                     Hans Hagen | PRAGMA ADE
         Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl

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On 1 May 2020, at 13:28, Hans Hagen j.hagen@xs4all.nl wrote:

On 5/1/2020 10:21 AM, Gerben Wierda wrote:

...

code it back to a \ ? E.g. something like { ‘\U{XXX}', '' },

\utfchar{100} \Uchar 100

Yes, but the question was: how do I code this in the XML and get it through my XML-lua-METAPOST-textext() path so that e.g.  or  in the XML end up as \ in my textext() string?

E.g. a 
 in XML becomes a \n when lmtx XML handling has read the XML (so gets transformed on read). I’ve been thinking about the route 
 -> \r -> \ (so, misusing \r to code a TeX-\ in the XML, but that would probably not robust.

The question is more: what is a good UTF8 character to use (the first 32 would be good candidates if they would work and end in the strings that xml.foo() of lmtx produces).

G

---

                                     Hans Hagen | PRAGMA ADE
         Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
  tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl

---

On 5/1/2020 1:45 PM, Gerben Wierda wrote:

...

On 1 May 2020, at 13:28, Hans Hagen j.hagen@xs4all.nl wrote:

On 5/1/2020 10:21 AM, Gerben Wierda wrote:

...

code it back to a \ ? E.g. something like { ‘\U{XXX}', '' },

\utfchar{100} \Uchar 100

Yes, but the question was: how do I code this in the XML and get it through my XML-lua-METAPOST-textext() path so that e.g.  or  in the XML end up as \ in my textext() string?

E.g. a 
 in XML becomes a \n when lmtx XML handling has read the XML (so gets transformed on read). I’ve been thinking about the route 
 -> \r -> \ (so, misusing \r to code a TeX-\ in the XML, but that would probably not robust.

The question is more: what is a good UTF8 character to use (the first 32 would be good candidates if they would work and end in the strings that xml.foo() of lmtx produces).

you could try

\xmltexentity{foo}{[overloaded foo]}

----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------