1. Length & Shortcircuit
- Posted by Ralf Nieuwenhuijsen <nieuwen at XS4ALL.NL>
Jun 23, 1998
-
Last edited Jun 24, 1998
atom a
a = 123
? length(a)
Why does this generate an error anyways.
I would prefer if it would return 1, since an atom operates the same as an
one element sequence!
This would make short-circuit even less usable.
I often type something like this
integer len
if atom (x) then
len = 1
else
len = length(x)
end if
I can't think of any reason to crash when I request a length, actually.
Ralf
2. Re: Length & Shortcircuit
From: Ralf Nieuwenhuijsen
Subject: Re: Length & Shortcircuit
>atom a
>a = 123
>? length(a)
>Why does this generate an error anyways.
>I would prefer if it would return 1, since an atom operates the
>same as an one element sequence!
Nope! They don't always operate the same. If atoms worked the
same as one-element sequences, what would this do?
atom a
a = 123
for count = 1 to length( a ) do
a[count] = {}
end for
Defining objects as one-element sequences, and having them work the
same way might make a little more sense...except that a sequence is
defined as a set of objects, so you'd have recursive definitions and
that'd be confusing...
I don't mind calling "if sequence() then" before testing lengths.
It's consistent with other sequence functions. Any other function that
requires the parameter to be a sequence will do a type-check crash if
you pass an atom. Internally, it's something like this:
global function length( sequence s )
return( peek(s_address+length_offset) )
end function
