Re: [Rd] formals assignment now strips attributres

[Patrick Burns]

Peter Dalgaard wrote:
Patrick Burns <[EMAIL PROTECTED]> writes:
 

But the buglet gets more aggressive if you edit the function:
> fjj <- function() x
> formals(fjj) <- list(x=c(a=2, b=4))
> fjj
function (x = c(2, 4))
x
> fjj()
a b
2 4
> fix(fjj) # do nothing but save
> fjj()
[1] 2 4
I'm quite sure that I wouldn't have noticed if my real function were
not broken.
Now I know that my functions will work if I assign the formals after I
edit the
function -- even though they look like they shouldn't work.
   

You did invite trouble by creating and subsequently a function that
_has_ no source representation though:
 

fjj <- function() x
formals(fjj) <- list(x=quote(c(a=2, b=4)))
fjj()
   

a b
2 4
 

fix(fjj)
fjj()
   

a b
2 4
But the point of using 'formals' in the first place is to get a
function that is self-contained.  The real application is more
like:
formals(fjj) <- list(x = an_object)
I want 'fjj' to work even when 'an_object' is nowhere to be
found.
'formals' worked as (I) expected in versions 1.8.0
through 1.9.1 at least. 

Pat
 

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