Re: matching "nothing" seems to be broken

Re: matching "nothing" seems to be broken

[Byron Rakitzis]

This is not really a bug, but it is misleading behavior
from rc.

The problem is that lists are not recursive in rc. Therefore
there is no way to put a null list inside another list. So
what happens when you type

foo=(a () b () c)

?

Well, rc strips out the "redundant" parentheses.

The same occurs for ~, since syntactically, what follows the
subject list is a list of patterns. (NOT a list of pattern
lists)

Therefore

	()

represents the empty list, but

	() ''

represents a list with an empty string in it that hasn't been
stripped down to

	''

by the parser yet.

matching "nothing" seems to be broken

[David J. Fiander]

I'm having a slight problem.  I want to be able to check to see
if a variable is either not set, or set to the empty string, so
I write

	if (~ $foo () '') echo all clear

The problem is that the list of words to compare $foo to is not
being evaluated properly (or at least I don't think so).  The
() is being removed for some reason, so 'rc -x' reports the
test "~ $foo ''".

However, the test "~ $foo ()" works; it is only parsed wrong
when the list of words to compare against is longer than one.

Has anybody else seen this?