[Rd] Exchange of information between functions aside from argument/return-value interface

Peter Ruckdeschel Peter.Ruckdeschel at uni-bayreuth.de
Wed Apr 4 21:25:59 CEST 2007


Thank you, Luke, once again.

>> [snipped away my original message; to be found on
>> https://stat.ethz.ch/pipermail/r-devel/2007-April/045219.html]

>> Or did I get something wrong?
> 
> I think you did. You seem to be thinking in terms of dynamic scope,
> which looks for variables in the caller and then the caller's caller.
> 
> Lexical scope addresses exactly this problem.  In lexical scope
> variable references are resolved on the basis of how function
> definitions are nested in the written code (hence the term lexical).
> If you define myH inside myF then free variables in myH are looked up
> first in myF and then in the context where myF is defined. How myH is
> called does not matter.  Nested functions in Pascal work the same way
> if that helps.

OK got it. I should have known this. I am pretty much embarrassed to
have bothered you.

Thanks again for your help
Peter



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