This one may not strictly be a bug, and it was certainly my
fault, but it took me a while to track it down and it is rather
strange:
funOne <- function(x)
{
funTwo <- 1:10
funTwo(x)
}
funTwo <- function(v) 2*v
funOne(5) # answer is 10 as expected
# now a different definition for funTwo with a match.arg
funTwo <- function(v, foo=c("small", "large"))
{
foo <- match.arg(foo)
print(foo)
2*v
}
funOne(5) # answer is 10, but foo is NULL
What happens is that in funOne I mask funTwo with a vector, but
that doesn't matter as the call to funTwo specifies
mode="function" (or something similar). But what happens when
funTwo includes a match.arg? In this case match.arg fails, and
the reason it fails is that sys.function(sys.parent()) in
match.arg evaluates to 1:10. If there is a bug here it is the
failure of sys.function to grab a function, with the result that
formal.args in match.fun is NULL.
Cheers, Jonathan.
--please do not edit the information below--
Version:
platform = sparc-sun-solaris2.7
arch = sparc
os = solaris2.7
system = sparc, solaris2.7
status =
major = 1
minor = 2.1
year = 2001
month = 01
day = 15
language = R
Search Path:
.GlobalEnv, Autoloads, package:base
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