Werner, et al --
It's been a long time, but this one I do remember -- the intent
of "then" in such constructs is definitely to separate components
of a path, and that phrase appears in several documents that I
have still lying around, including the paper in SP&E and one
that seems to have meant for some ACM SIG.
This may be an instance of something I added that wasn't carried
over into the development organization that distributed "official"
source.
Brian
On Sat, 22 Mar 2008, Werner LEMBERG wrote:
I suppose it is going to boil down to a matter of "taste".
Old AT&T pic treated
line from 1,1 then up 1
exactly the same as
line from 1,1 up 1
As I read pic documentation, these *should* behave differently; the
former should plot two line segments, the latter only one. If AT&T
pic produces identical results in both cases, then IMO it doesn't
behave as documented, so could be considered broken.
Yes, AT&T is broken here, I think. In CSTR 116, section 8 (`Lines and
Splines'), it is explicitly written:
The word `then' separates components of the path.
And examples are given like that:
line right 1 then down .5 left 1 then right 1
which makes a zig-zag line having three components. So it is clear
that `components' are visible parts of the line, not syntactical
parts. However, examples using the `from' keyword are given only for
arcs, so I assume that during development of pic this particular case
slipped through the grammar.
Brian, could you comment, please?
Werner
