[metapost] Bug? Parsing def := := enddef;
nvitacolonna at gmail.com
Thu Jan 21 14:18:50 CET 2010
In article <Pine.LNX.4.61.1001211309560.9112 at linux.bop.eps.gda.pl>,
Boguslaw Jackowski <B_Jackowski at GUST.org.pl> wrote:
> > according to The METAFONTbook, a macro definition can be 'def' followed
> > by a symbolic token followed by either = or :=.
> > But the following gives an error:
> > This is MetaPost, version 1.208 (kpathsea version 3.5.7dev)
> > **\relax
> > *def := := enddef;
> > ! Missing `=' has been inserted.
> > <to be read again>
> > :=
> > <*> def := :=
> > enddef;
> > ?
> > That looks like a small bug.
> Not sure. MF behaves similarly:
> This is METAFONT, Version 2.71828 (Web2c 7.5.2) (base=mf 2006.4.9) 21 JAN
> 2010 13:06
> ! Missing `=' has been inserted.
> <to be read again>
> l.1 def := :=
> Was this behavior reported to Knuth?
Well, I haven't (yet). As I've said, this may be expected behaviour
(otherwise, prof. Knuth could have defined (var)def's to just use '=').
So, not sure it is worth filing a bug report.
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