Re: a feature I wish rc had

Re: a feature I wish rc had

[Paul Haahr]

yes, these are all good suggestions, but they don't feel right
to me.  what i want is some notation for saying

	save (*.[ch] - y.tab.c xxx.*)

while, of course, would generate all .c and .h files other than
y.tab.c and anything that matched xxx.*.  note that, in this
hypothetical, the things after the - are not glob expaned but
just used to filter the list.

and while i could probably come up with a remove operation that
had the same semantics, it's missing the notational convenience.
on the other hand, i'm not sure i'd want to use a shell that had
such syntax in it.

(by the way:  i tend to dislike using eval to get around the
meta-character rules, but that's just my hangup.)

Re: a feature I wish rc had

[Mark-Jason Dominus]

> 	save (*.[ch] - y.tab.c xxx.*)
> 
> note that, in this hypothetical, the things after the - are not glob
> expanded

Why not?

Consider a `set-subtract' command, which is a little like `echo'.

	set-subtract [foo]... - [bar]...

echoes all the words that are on the left of the `-' but not on the
right. Then instead of

> 	save (               *.[ch] - y.tab.c xxx.* )

use
	save `{ set-subtract *.[ch] - y.tab.c xxx.* }

The globbing is just what you want.

Re: a feature I wish rc had

[Scott Schwartz]

| i've always wanted this in a shell, but never found a convenient notation  
| for it.  if someone can suggest one, it's certainly a potential es feature.

One idea is to add list comprehensions to your language.  List
comprehensions are the list version of set builder notation.  They have
the same power as nested for loops, but with a more compact syntax.

Re: a feature I wish rc had

[rsalz]

>Anybody feel like producing an all builtin function for this? 
>Something like "remove pattern list" or "remove index list".  It
>shouldn't be too hard.
Trivial:
fn remove { pat=() i=() list=() {
    pat=$1
    shift || { echo 'Usage erorr' >[1=2] ; return 1; }
    for (i) eval ~ $i $pat || list=($list $i)
    echo $list
} }
remove '*.c' foo.c bar baz.c

path=`{remove /usr/share/bin $path}

Re: a feature I wish rc had

[Tom Culliton x2278]

>> It would be especially powerful if one could take things
>> out of implicit lists, ie say 'all filenames of this pattern, except
>> filenames of that pattern' conveniently.
	
>i've always wanted this in a shell, but never found a convenient notation  
>for it.  if someone can suggest one, it's certainly a potential es feature.
>
>i just use ``ls|grep -v'' usually.

I usually use sed to do this kind of list manipulation, for example
when we have net problems one of the following works quite well to pull
the NFS mounted partions out of my path.

	path=`{echo $path | sed 's:/usr/share/bin::'}

	eval `{whatis path | sed 's:/usr/share/bin::'}

The second could easily be turned into a general function to do the
job, but being able to fetch it out of my history makes that more
bother (and clutter in the environment) than it's worth.

Anybody feel like producing an all builtin function for this? 
Something like "remove pattern list" or "remove index list".  It
shouldn't be too hard.

Re: a feature I wish rc had

[Paul Haahr]

> rc has convenient ways of adding things to a list, but it has
> no particularly easy way of doing the converse, taking something
> out of one. It would be especially powerful if one could take things
> out of implicit lists, ie say 'all filenames of this pattern, except
> filenames of that pattern' conveniently.

i've always wanted this in a shell, but never found a convenient notation  
for it.  if someone can suggest one, it's certainly a potential es feature.

i just use ``ls|grep -v'' usually.

a feature I wish rc had

[Chris Siebenmann]

 rc has convenient ways of adding things to a list, but it has
no particularly easy way of doing the converse, taking something
out of one. It would be especially powerful if one could take things
out of implicit lists, ie say 'all filenames of this pattern, except
filenames of that pattern' conveniently.

 Just today's gratuitious feature idea (well, not too gratuitious).

	- cks