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Codetools Query (repost)

3 messages · Saptarshi Guha, Luke Tierney

Saptarshi Guha
# 
Sorry for reposting,  i keep forgetting this should be plain text.
Will not make this mistake again

Hello,

The following code

moo <- function(a=1){ x=1; x=x+y}
funs <- new.env()
enter <- function(type, v, e, w){
  assign(v, TRUE, funs)
}
library(codetools)
collectUsage(moo, enterGlobal = enter)


adds + to the environment funs i.e.

funs: "=" "{" "+" "y"

How can i ignore variables which are present in base, utils, stat
environments from being added (equivalently(?) symbols present in R
when R is started)

I tried



funs <- new.env()
enter <- function(type, v, e, w){
  if(codetools:::isBaseVar(v, w$env) || codetools:::isStatsVar(v, w$env)
     || codetools:::isUtilsVar(v, w$env) || v == "Quote")
    return()
  assign(v, TRUE, funs)
}

library(codetools)
collectUsage(moo, enterGlobal = enter)

but this threw

Error in exists(v, envir = e, inherits = FALSE, mode = "function") :
  invalid 'envir' argument

Cheers
Luke Tierney
# 
You really don't want to use internals like isBaseVar as there is no
guarantee they will continue to exist.  Even collectUsage and otehr
things mentioned on the same page may need to change if this is
reimplemented.

The most robust approach is to use findGlobals and omit what you don't
want, e.g.

     > omit <- ls("package:base", all.names=TRUE)
     > setdiff(findGlobals(moo),omit)
     [1] "y"

If you do want to use chollectUsage you could use something like

     funs <- new.env()
     omit <- ls("package:base", all.names=TRUE)
     enter <- function(type, v, e, w){
 	if (! v %in% omit)
 	    assign(v, TRUE, funs)
     }
     collectUsage(moo, enterGlobal = enter)

If %in% is too slow create a hashed envorinment and use exists().

Best,

luke
On Tue, 15 Jan 2013, Saptarshi Guha wrote: