R help - Jun 2010 - What is wrong with this code?

Here it is:

read.inputs<-function(infile) {

   for (counter in 1:length(input.list)) {
      seek(infile,where=0,origin='start')
      newline<-readLines(infile,n=1)
      while(length(newline)>0) {
 
if(!is.na(grep(as.character(input.list[[counter]][1]),newline)[1])) {
          break
        }
        newline<-readLines(infile,n=1)
      }
      if (length(newline)>0) input.list[[counter]][2](infile)
   }

}

Conceptually, it is pretty simple:  I just want to read through a short
file, looking for several key words ('input.list[[counter]][1]').  If
one of these words is found, the reading loop is exited and the function
appropriate to found word ('input.list[[counter]][2]') is called.

The code stops running and returns an error of "attempt to apply
non-function" the very first time it hits the "break" statement,
which
seems to me to be the most innocuous part of the entire routine.
Putting in debug statements, it seems that it crashes right at
"break".
Why on Earth would R not like a "break" statement?

Also, there must be a more elegant way to do character matching than the
"grep" thing I have kluged together.  Any ideas on that are welcome as
well.

Thank you very much for your help.

Could you please provide a small reproducible example of the input you 
have and output you'd like, as the posting guide asks for? There most 
likely is much simplified way to do what you want, avoiding for loops 
and therefore `break` altogether.

Cable, Samuel B Civ USAF AFMC AFRL/RVBXI wrote:
> Here it is:
> 
> read.inputs<-function(infile) {
> 
>    for (counter in 1:length(input.list)) {
>       seek(infile,where=0,origin='start')
>       newline<-readLines(infile,n=1)
>       while(length(newline)>0) {
>  
> if(!is.na(grep(as.character(input.list[[counter]][1]),newline)[1])) {
>           break
>         }
>         newline<-readLines(infile,n=1)
>       }
>       if (length(newline)>0) input.list[[counter]][2](infile)
>    }
> 
> }
> 
> Conceptually, it is pretty simple:  I just want to read through a short
> file, looking for several key words ('input.list[[counter]][1]'). 
If
> one of these words is found, the reading loop is exited and the function
> appropriate to found word ('input.list[[counter]][2]') is called.
> 
> The code stops running and returns an error of "attempt to apply
> non-function" the very first time it hits the "break"
statement, which
> seems to me to be the most innocuous part of the entire routine.
> Putting in debug statements, it seems that it crashes right at
"break".
> Why on Earth would R not like a "break" statement?
> 
> Also, there must be a more elegant way to do character matching than the
> "grep" thing I have kluged together.  Any ideas on that are
welcome as
> well.
> 
> Thank you very much for your help.
> 
> ______________________________________________
> R-help at 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.