capture.R: make sure variable is assigned in local enviroment

capture.R

capture <- function(...) {
    vars<-sapply(substitute(...()), deparse)
    pf <- parent.frame()
    Map(assign, vars, mget(Filter(exists, vars), envir=pf, inherits = TRUE), MoreArgs=list(envir=pf))
}

test.capture.R

#capture will find a variable from an enclosing environment and will reassign it to the current (local) environment.
#Ignores variable names that do not exist

a <- c(3,7,11)
f <- list()

for(i in 1:3) {
    f[[i]] <- local({capture(i, gobble); function(x) a[i]+x})
}

f[[1]](1)
# [1] 4
f[[3]](1)
# [1] 12