Re: [RFC] linecut addition

[Steven Schubiger]

Matthew Woehlke <address@hidden> wrote:

> Well, yes, I would hope so. If you can't write 'a + b' in your program, 
> something is wrong ;-). (Use case is of course e.g. scripts where the 
> beginning line is not known in advance, but you know you want N lines 
> total.)

Am I right assuming you mean something like '-20,+3' ?

> '-N' is already a fairly common convention, so I don't expect problems. 
> And I stole '+N' from sed, of course :-).

OK.

> Ok. (An alternative, if sed-like format wins, would of course be '5,$', 
> but '5,-0' is fine.)

I'm a bit hesitant to make it look too much like sed.
And I must correct myself here: "1,-1" is valid, whereas "1,-0" isn't.

> I was asking you :-). Personally I think printing lines backwards is 
> probably not so good an idea, so I would either match only the first 
> line, or else print a warning to stderr.

I think we should disallow it entirely. Worry later about the details.

> Anyway '5,2' was just an 
> "obvious" example; I would expect this to be more likely with a range 
> like '5,-5' on input with fewer than nine lines.

Agreed (except s/nine/ten/).