[luatex] Negative value(s) of \endlinechar

[Heiko Oberdiek]

Hello,

there is some discussion of `\endlinechar' in the chat
http://chat.stackexchange.com/rooms/41/tex-latex-and-friends

* David Carlisle detects that \endlinechar has only one
  negative value `-1'
  http://chat.stackexchange.com/transcript/message/15629938#15629938

A test file:

\catcode`\{=1
\catcode`\}=2
\catcode`\#=6 %
\def\test#1{%
  \begingroup
    \endlinechar=#1\relax
    \immediate\write16{<#1=\the\endlinechar>}%
  \endgroup
}
\test{1}
\test{0}
\test{-1}
\test{-2}
\test{-126}
\test{-127}
\test{-128}
\test{-129}
\test{-254}
\test{-255}
\test{-256}
\test{-257}
\test{-1000}

\csname @@end\endcsname\end

Result:

<1=1>
<0=0>
<-1=-1>
<-2=-1>
<-126=-1>
<-127=-1>
<-128=-1>
<-129=-1>
<-254=-1>
<-255=-1>
<-256=-1>
<-257=-1>
<-1000=-1>

* \endlinechar has an upper limit of 127. What is the reason
  for this constraint?

Yours sincerely
  Heiko Oberdiek