[R] Scope and apply-type functions

[jamie.f.olson]

So, I've been confused by this for a while.  If I want to create functions in
an apply, it only uses the desired value for the variable if I create a new
local variable:

> lapply(1:5,function(h){k=h;function(){k}})[[1]]()
[1] 1
> lapply(1:5,function(k){function(){k}})[[1]]()
[1] 5
> 

Normally, a function will use values for a variable if the variable is local
to the definition of the function:

> a = function(x){function(){x}}
> a(5)
function(){x}

> a(5)()
[1] 5
> a(6)()
[1] 6


So why doesn't this work for apply?  Does apply work more like loops, with a
shared variable that changes values so that the first function defined
actually uses the last value of the variable?

> a = list();for (k in 1:5){a = c(a,function(){k})}
> a[[1]]()
[1] 5
> 


Or is there something else entirely?

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