On Thu, 10 Jun 1999 [EMAIL PROTECTED] wrote:
> Hi,
>
> I had occasion to want the starting and ending offsets of a certain chunk. I
> toyed with providing new chunklike syntax, such as 'the lineOffsets 1 to 4 of
> it'; didn't like it; then hit upon this:
>
> the range of line 2 to 4 of it
>
> Which would return two offsets as comma-delimited integers.
Not to try to outdo Ruediger or anything, but this kind of thing is
not too hard to do now:
put the number of characters in line 1 of it into myvar
put comma & the number of characters in line 2 to 4 of it after myvar
> It also works for
> containers:
>
> container theCont = my title
> get the range of word 2 of theCont
I don't know "containers", perhaps you could elaborate. From the
above example, they look like "references" in C++ or Java (and it
looks like you're also co-mingling variable and property syntax, which
has been discussed on this list previously).
> It also preserves container opacity -- IE, the 'black bag' effect of passing
> a chunk to a handler that accepts containers:
>
> doMyThing item 3 of something
> on doMyThing container theCont
> get the range of char 2 to 3 of theCont -- would be "2,3", regardless of
> what theCont really is
> end doMyThing
This looks like call-by-reference, a feature MetaCard already has,
though you can (currently) only apply it to entire variables and not
chunks within variables. The MetaCard syntax would be:
on doMyThing @theCont
> Is there a 'range' function elsewhere in xland -- does this conflict
> in any way? I like it partly because it's friendly and doesn't
> corrupt the all-important black bag effect, partly because my
> compiler makes implementing this trivial.
The only thing I'd recommend is caution before pushing this type of
thing too hard. In my experience, people have a lot of trouble even
grasping the concept of call-by-reference, let alone where you've got
some spaghetti code such as where one function calls another one and
both change the "chunk" that gets passed in.
Regards,
Scott
> Dan
>
********************************************************
Scott Raney [EMAIL PROTECTED] http://www.metacard.com
MetaCard: You know, there's an easier way to do that...
