[R] How to use current value of variable in function definition?

Allan Engelhardt allane at cybaea.com
Thu Jul 2 18:46:44 CEST 2009


Must be the heat or something but I can't get my brain into gear and 
figure out how to get something like

if (1) { c <- 1; foo <- function () print(c); }
c <- 2
foo()

to print 1, not 2.  (The real life example is a little more complex, but 
you get the idea.  I don't want the variable c in the function 
definition, I want its value at that time.)

The only thing I have been able to come up with is something like

if (1) foo <- (function () { c <- 1; return(function () print(c)) })()
c <- 2
foo()
# [1] 1

but that just hurts.  Please make the pain go away.

Can someone wake up my brain?

Allan.




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