debugcall {utils} | R Documentation

## Debug a Call

### Description

Set or unset debugging flags based on a call to a function. Takes into account S3/S4 method dispatch based on the classes of the arguments in the call.

### Usage

    debugcall(call, once = FALSE)
    undebugcall(call)

### Arguments

`call` | An R expression calling a function. The called function will be debugged. See Details.
`once` | logical; if `TRUE`, debugging only occurs once, as via `debugonce`. Defaults to `FALSE`

### Details

`debugcall` debugs the non-generic function, S3 method or S4 method that would be called by evaluating `call`. Thus, the user does not need to specify the signature when debugging methods. Although the call is actually to the generic, it is the method that is debugged, not the generic, except for non-standard S3 generics (see `isS3stdGeneric`).

### Value

`debugcall` invisibly returns the debugged call expression.

### Note

Non-standard evaluation is used to retrieve the `call` (via `substitute`). For this reason, passing a variable containing a call expression, rather than the call expression itself, will not work.

### See Also

`debug` for the primary debugging interface

### Examples

    ## Not run:
    ## Evaluate call after setting debugging
    ##
    f <- factor(1:10)
    res <- eval(debugcall(summary(f)))

    ## End(Not run)

[Package utils version 3.5.1 Index]