Re: The ~ parameter expansion flag: bug or misunderstanding

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Sep 3,  4:14pm, Peter Stephenson wrote:
}
} The documentation isn't very clear

While we're sort of on the subject, the (l) and (r) padding flags say:

     The arguments :STRING1: and :STRING2: are optional; neither, the
     first, or both may be given.  Note that the same pairs of
     delimiters must be used for each of the three arguments.  The
     space to the left will be filled with STRING1 (concatenated as
     often as needed) or spaces if STRING1 is not given.  If both
     STRING1 and STRING2 are given, string2 is inserted once directly
     to the left of each word, truncated if necessary, before STRING1
     is used to produce any remaining padding.

What this doesn't say is that if STRING2 is the empty string, a space
is inserted instead:

torch% f=f
torch% print X${(l:2::.:)f}X
X.fX
torch% print X${(l:2::.:::)f}X
X fX
torch% print X${(l:5::.:::)f}X
X... fX
torch% print X${(l:5::.::+:)f}X
X...+fX

I'm not sure if that's a bug, or intentional.  Of course one might ask
why one would bother with the empty :: when it could simply be left out.