* A fresh approach to learning Context.
@ 2002-03-01 23:20 John Culleton
2002-03-02 13:01 ` Hans Hagen
0 siblings, 1 reply; 4+ messages in thread
From: John Culleton @ 2002-03-01 23:20 UTC (permalink / raw)
Context is built on pdftex and pdftex should be in most
instances a superset of plain TeX. So a plain TeX file should
compile on both pdftex and Context. This represents a radically
different way to approach Context. Start with something already
known to be workable and go from there. This is my new approach
to learning Context and I will ride this horse till it gets tired.
Following this idea I compiled an existing file with pdftex and then
with Context. With minor tweaks things worked. I did get one
strange and apparently non-germane error message. I use
eplain.tex extensively. One line in eplain that works with plain and
works
with pdftex causes an error message in Context thus:
! Use of \def doesn't match its definition.
l.79 \def\hpenalty
{\ifvmode\leavevmode\fi \penalty}%
This has nothing to do with my code. Something in eplain
doesn't work in Context. Everything else seems fine.
Can anyone suggest an explanation of the above error message?
JOhn Culleton
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: A fresh approach to learning Context.
2002-03-01 23:20 A fresh approach to learning Context John Culleton
@ 2002-03-02 13:01 ` Hans Hagen
2002-03-03 18:44 ` John Culleton
0 siblings, 1 reply; 4+ messages in thread
From: Hans Hagen @ 2002-03-02 13:01 UTC (permalink / raw)
Cc: ntg-context
At 06:20 PM 3/1/2002 -0500, you wrote:
>Context is built on pdftex and pdftex should be in most
>instances a superset of plain TeX. So a plain TeX file should
>compile on both pdftex and Context. This represents a radically
>different way to approach Context. Start with something already
>known to be workable and go from there. This is my new approach
>to learning Context and I will ride this horse till it gets tired.
>
>Following this idea I compiled an existing file with pdftex and then
>with Context. With minor tweaks things worked. I did get one
>strange and apparently non-germane error message. I use
>eplain.tex extensively. One line in eplain that works with plain and
>works
>with pdftex causes an error message in Context thus:
>
>! Use of \def doesn't match its definition.
>l.79 \def\hpenalty
> {\ifvmode\leavevmode\fi \penalty}%
>
>This has nothing to do with my code. Something in eplain
>doesn't work in Context. Everything else seems fine.
>
>Can anyone suggest an explanation of the above error message?
it seems that somehow the primitiev \def has been defined,
add the line \show\def before line 79 and see what happened, move this line
up till the primitive def shows up.
Hans
-------------------------------------------------------------------------
Hans Hagen | PRAGMA ADE | pragma@wxs.nl
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: A fresh approach to learning Context.
2002-03-02 13:01 ` Hans Hagen
@ 2002-03-03 18:44 ` John Culleton
2002-03-03 21:27 ` Hans Hagen
0 siblings, 1 reply; 4+ messages in thread
From: John Culleton @ 2002-03-03 18:44 UTC (permalink / raw)
Cc: ntg-context
> >with pdftex causes an error message in Context thus:
> >
> >! Use of \def doesn't match its definition.
> >l.79 \def\hpenalty
> > {\ifvmode\leavevmode\fi \penalty}%
> >
>> it seems that somehow the primitiev \def has been defined,
>
> add the line \show\def before line 79 and see what happened, move
> this line up till the primitive def shows up.
>
> Hans
Following this advice I found a strange piece of code in
eplain that causes the problem. Then I went to xeplain (eplain
annotated) and found an explanation of the code.
Here is the xeplain.tex code and explanation:
------------------------------
%
% In order to do anything with ^^L inside a macro, it must
% be made non-\outer.
%
\def^^L{\par}%
---------------------
If I comment out this line then Context offers no error message
as indicated above. I have no idea what the code does. It is the
first instance I have seen of a \def that was not immediately
followed with a command name beginning with a backslash.
I will teke this issue to the eplain mailing list.
--
John Culleton, john@wexfordpress.com
Able Indexers and Typesetters
http://wexfordpress.com
<------------------------------------>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: A fresh approach to learning Context.
2002-03-03 18:44 ` John Culleton
@ 2002-03-03 21:27 ` Hans Hagen
0 siblings, 0 replies; 4+ messages in thread
From: Hans Hagen @ 2002-03-03 21:27 UTC (permalink / raw)
Cc: ntg-context
At 01:44 PM 3/3/2002 -0500, you wrote:
> > >with pdftex causes an error message in Context thus:
> > >
> > >! Use of \def doesn't match its definition.
> > >l.79 \def\hpenalty
> > > {\ifvmode\leavevmode\fi \penalty}%
> > >
> >> it seems that somehow the primitiev \def has been defined,
> >
> > add the line \show\def before line 79 and see what happened, move
> > this line up till the primitive def shows up.
> >
> > Hans
>Following this advice I found a strange piece of code in
>eplain that causes the problem. Then I went to xeplain (eplain
>annotated) and found an explanation of the code.
>
>Here is the xeplain.tex code and explanation:
>\def^^L{\par}%
in context, ^^L has catcode 'endofline', so this should be:
\catcode`\^^L=\active \def^^L{\par}
btw, be aware that when you load eplain after context, much features of
context will break as i suppose that eplain has its own otr and subsystems.
(loading eplain first and context afterwards would be saver)
if you want some eplain functionality, you'd better copy the 'useful' code
to a file and load that one
Hans
-------------------------------------------------------------------------
Hans Hagen | PRAGMA ADE | pragma@wxs.nl
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------
fall-back web server:
www.pragma-pod.nl
-------------------------------------------------------------------------
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