In R <= 2.13.x, calling 'parse( con)' where 'con' is a connection, 'options(
keep.source)' is TRUE, and default 'srcfile' would preserve the source. In R
>= 2.14.1, it doesn't.
> tf <- tempfile()
> options( keep.source=TRUE)
> texto <- c( 'function() { # comment', '}')
> parse( text=texto)
expression(function() { # comment
})
> cat( texto, file=tf, sep='\n')
> parse( file=tf)
expression(function() { # comment
})
> parse( file( tf))
expression(function() {
})
> parse( textConnection( texto))
expression(function() {
})
and yes I didn't bother closing any connections.
My suspicion is that this change is unintentional, and it seems to me that the
best option would be for 'connection' to work like 'text' does here, ie to
attach a 'srcfilecopy' containing the contents.
I didn't submit a bug report because the documentation (which hasn't changed in
this respect) actually doesn't say what 'parse' should do with 'connection' (as
opposed to 'text' or 'file') argument when 'getOption( keep.source)' is TRUE
and 'srcfile' is NULL. [BTW it's also unstated which argument takes precedence
if a non-default 'srcfile' argument is specified.] So some additional
explanation is needed there at a minimum, but also a decision as to what the
best behaviour would be.
bye
Mark
Mark Bravington
CSIRO CMIS
Marine Lab
Hobart
Australia
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