anxiety.R

# Function factory
make_adder <- function(x) {
  function() x + 1
}

# Create list of functions with Map
funs <- Map(make_adder, 1:10)

unlist(Map(function(f) f(), funs))
# [1]  2  3  4  5  6  7  8  9 10 11

# Create list of functions with a for loop
funs2 <- list()
for (x in 1:10) {
  funs2[[x]] <- make_adder(x)
}

unlist(Map(function(f) f(), funs2))
# [1] 11 11 11 11 11 11 11 11 11 11

# But we're cool if the one-off function is called on each loop
returns <- list()
for (x in 1:10) {
  returns[[x]] <- make_adder(x)()
}
unlist(returns)
# [1]  2  3  4  5  6  7  8  9 10 11