[R] 'autocompletion' of named elements of a list

[Håvard Rue]

I had an obscure bug that boiled down to this ``feature'' in R, 

Read 3921 items
> A = list(aa = 1)
> A
$aa
[1] 1

> if (A$a) print("a is there")
[1] "a is there"

The test appear to check is A$a is TRUE, but what happen is that it
auto-complete (silently), and expand to 'A$aa'. 

The problem was caused by the fact that I had also a element named 'a'
which was evaluated to NULL,  like

> A$a = NULL
> A
$aa
[1] 1

> if (A$a) print("a is there")
[1] "a is there"

since NULL elements are removed from the list, and that A$a auto-expand
to A$aa, my error appeared.

To me, this seems not a feature I want in order to have a robust
program. 

Is there any option to turn this ''feature'' off? 

Best,
H



-- 
 Håvard Rue
 Department of Mathematical Sciences
 Norwegian University of Science and Technology
 N-7491 Trondheim, Norway
 Voice: +47-7359-3533    URL  : http://www.math.ntnu.no/~hrue  
 Fax  : +47-7359-3524    Email: havard.rue at math.ntnu.no

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