> So you are saying to make sense this would need to be > > > match.call(definition=g , call=quote(g(1)) ) > g(x = 1)
Yes. What would you expect to get from match.call() outside of a function if you don't give it a call argument? It uses the default value for 'call', sys.call(sys.parent()), but sys.parent() gives 0 at the top level, the same as when it is called from a function called from the top level, so the default value of call is not useful when match.call is called from the top level. . Bill Dunlap TIBCO Software wdunlap tibco.com On Tue, Jul 15, 2014 at 5:19 PM, David Winsemius <dwinsem...@comcast.net> wrote: > > On Jul 15, 2014, at 5:04 PM, William Dunlap wrote: > >> Does it make sense to call match.call outside of a function without >> specifying both the function definition and the call to the function? > > > My puzzlement came from the different response to these two commands: > > match.call(g) > match.call(definition=g) > > I thought they would be the same. So you are saying to make sense this would > need to be > >> match.call(definition=g , call=quote(g(1)) ) > g(x = 1) > > > > -- > David. > > >> I agree that the error message is misleading. Also, the return value >> when call is not supplied does not seem useful, although it is >> possible that it is correct in some technical sense. >> >>> match.call(definition=function(FirstArg, SecondArg)NULL, >>> quote(anyFuncName(S=2, 1))) >> >> anyFuncName(FirstArg = 1, SecondArg = 2) >>> >>> match.call(function(FirstArg, SecondArg)NULL, quote(anyFuncName(S=2, 1))) >> >> anyFuncName(FirstArg = 1, SecondArg = 2) >>> >>> # without supplying 'call': >>> match.call(definition=function(FirstArg, SecondArg)NULL) >> >> Error in match.call(definition, call, expand.dots) : >> unused argument (definition = function(FirstArg, SecondArg) NULL) >>> >>> match.call(function(FirstArg, SecondArg)NULL) >> >> match.call(FirstArg = function(FirstArg, SecondArg) NULL) >> >> >> >> >> >> >> >> Bill Dunlap >> TIBCO Software >> wdunlap tibco.com >> >> >> On Tue, Jul 15, 2014 at 4:27 PM, David Winsemius <dwinsem...@comcast.net> >> wrote: >>> >>> The help page says: >>> >>> "Calling match.call outside a function without specifying definition is >>> an >>> error." >>> >>> And yet when I send a function with a 'definition' argument it errors: >>> >>>> g >>> >>> function(x, y=NULL, z=NULL) invisible(NULL) >>>> >>>> match.call(definition=g) >>> >>> Error in match.call(definition, call, expand.dots) : >>> unused argument(s) (definition = g) >>> >>> I wondered if this had something to do with primitive functions and their >>> ignoring names but: >>> >>>> is.primitive(match.call) >>> >>> [1] FALSE >>> >>> Calling with an unnamed first argument succeeds: >>> >>>> match.call(g ) >>> >>> match.call(x = g) >>> -- >>> >>> David Winsemius, MD >>> Alameda, CA, USA >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-help >>> PLEASE do read the posting guide >>> http://www.R-project.org/posting-guide.html >>> and provide commented, minimal, self-contained, reproducible code. > > > David Winsemius, MD > Alameda, CA, USA > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
