* Re: wrong array range with (r) flag on scalar?
[not found] ` <150305084408.ZM20963@torch.brasslantern.com>
@ 2015-03-05 17:06 ` Peter Stephenson
2015-03-08 22:53 ` Han Pingtian
0 siblings, 1 reply; 3+ messages in thread
From: Peter Stephenson @ 2015-03-05 17:06 UTC (permalink / raw)
To: zsh-workers
couldn't resist rubbing it in at the end :-)
pws
diff --git a/Doc/Zsh/params.yo b/Doc/Zsh/params.yo
index d044f87..7b127bc 100644
--- a/Doc/Zsh/params.yo
+++ b/Doc/Zsh/params.yo
@@ -187,7 +187,17 @@ from the end of the array tt(foo), and
Subscripting may also be performed on non-array values, in which
case the subscripts specify a substring to be extracted.
For example, if tt(FOO) is set to `tt(foobar)', then
-`tt(echo $FOO[2,5])' prints `tt(ooba)'.
+`tt(echo $FOO[2,5])' prints `tt(ooba)'. Note that
+some forms of subscripting described below perform pattern matching,
+and in that case the substring extends from the start of the match
+of the first subscript to the end of the match of the second
+subscript. For example,
+
+example(string="abcdefghijklm"
+print ${string[+LPAR()r+RPAR()d?,+LPAR()r+RPAR()h?]})
+
+prints `tt(defghi)'. This is an obvious generalisation of the
+rule for single-character matches.
subsect(Array Element Assignment)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: wrong array range with (r) flag on scalar?
2015-03-05 17:06 ` wrong array range with (r) flag on scalar? Peter Stephenson
@ 2015-03-08 22:53 ` Han Pingtian
2015-03-09 16:37 ` Bart Schaefer
0 siblings, 1 reply; 3+ messages in thread
From: Han Pingtian @ 2015-03-08 22:53 UTC (permalink / raw)
To: zsh-workers
On Thu, Mar 05, 2015 at 05:06:38PM +0000, Peter Stephenson wrote:
> couldn't resist rubbing it in at the end :-)
>
> pws
>
>
> diff --git a/Doc/Zsh/params.yo b/Doc/Zsh/params.yo
> index d044f87..7b127bc 100644
> --- a/Doc/Zsh/params.yo
> +++ b/Doc/Zsh/params.yo
> @@ -187,7 +187,17 @@ from the end of the array tt(foo), and
> Subscripting may also be performed on non-array values, in which
> case the subscripts specify a substring to be extracted.
> For example, if tt(FOO) is set to `tt(foobar)', then
> -`tt(echo $FOO[2,5])' prints `tt(ooba)'.
> +`tt(echo $FOO[2,5])' prints `tt(ooba)'. Note that
> +some forms of subscripting described below perform pattern matching,
> +and in that case the substring extends from the start of the match
> +of the first subscript to the end of the match of the second
> +subscript. For example,
> +
> +example(string="abcdefghijklm"
> +print ${string[+LPAR()r+RPAR()d?,+LPAR()r+RPAR()h?]})
> +
> +prints `tt(defghi)'. This is an obvious generalisation of the
> +rule for single-character matches.
>
> subsect(Array Element Assignment)
>
Looks like this is also the case for (i):
localhost% foo=abcdefgh
localhost% print $foo[(r)ab,(i)fg]
abcdefg
localhost%
Though
localhost% print $foo[(i)fg]
6
localhost%
But according to the new contents of manual, this is the same case as
"(r)fg".
Thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: wrong array range with (r) flag on scalar?
2015-03-08 22:53 ` Han Pingtian
@ 2015-03-09 16:37 ` Bart Schaefer
0 siblings, 0 replies; 3+ messages in thread
From: Bart Schaefer @ 2015-03-09 16:37 UTC (permalink / raw)
To: zsh-workers
On Mar 9, 6:53am, Han Pingtian wrote:
}
} Looks like this is also the case for (i):
}
} localhost% foo=abcdefgh
} localhost% print $foo[(r)ab,(i)fg]
} abcdefg
} localhost%
}
} Though
}
} localhost% print $foo[(i)fg]
} 6
} localhost%
}
} But according to the new contents of manual, this is the same case as
} "(r)fg".
You can't use (i) in ranges. $s[(i)ab,(i)fg] is an "invalid subscript";
the end of the range is not treated the same as the start.
So although $s[(r)fg] is the same as $s[$s[(i)fg]], $s[(r)ab,(r)fg] is
not the same as $s[$s[(i)ab],$s[(i)fg]].
The foregoing of course all applies only to indexes on scalars; for an
index on an array, the pattern match and resulting index values apply
to entire array elements, so there are no substrings to extract.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-03-09 16:37 UTC | newest]
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[not found] ` <150305084408.ZM20963@torch.brasslantern.com>
2015-03-05 17:06 ` wrong array range with (r) flag on scalar? Peter Stephenson
2015-03-08 22:53 ` Han Pingtian
2015-03-09 16:37 ` Bart Schaefer
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