recover {methods} | R Documentation |
This function allows the user to browse directly on any of the
currently active function calls, and is suitable as an error option.
The expression options(error=recover)
will make this
the error option.
recover()
When called, recover
prints the list of current calls, and
prompts the user to select one of them. The standard R
browser
is then invoked from the corresponding
environment; the user can type ordinary S language expressions to be
evaluated in that environment.
When finished browsing in this call, type c
to return to
recover
from the browser. Type another frame number to browse
some more, or type 0
to exit recover
.
WARNING: Do not use the special Q
command to go directly
from the browser to the prompt level of the evaluator. This currently
interacts with recover
to effectively turn off the error option
for the next error (on subsequent errors, recover
will be called normally)
Nothing useful is returned. However, you can invoke
recover
directly from a function, rather than through the error option shown
the usage section. In this case, execution continues after you type
0
to exit recover
.
The R recover
function can be used in the same way as the
S-Plus function of the same name; therefore, the error option shown is
a compatible way to specify the error action. However, the actual
functions are essentially unrelated and interact quite differently
with the user.
Programming with Data, (John M. Chambers, Springer, 1998). See the compatibility note above, however.
See dump.frames
and debugger
for
the more traditional approach to error recovery.