Just to be completely clear, variables are only at top level scope if you declare them at top-level scope. The variables "x" below are completely encapsulated within f1 and f2. The variables at top-level scope are intentional in the code below--I really do intend f1, f2, and how_many_times_functions_have_been_called to refer to the same entity throughout the file.
how_many_times_functions_have_been_called = 0
f1 = ->
how_many_times_functions_have_been_called += 1 # refers to top-level scope
console.log x # undefined
x = 1
console.log x # 1
f2 = ->
f1() # refers to f1 at top-level scope
how_many_times_functions_have_been_called += 1 # refers to lop-level scope
console.log x # undefined
x = 2
console.log x # 2
f1() # you can call f1, it's at top-level scope
f2() # you can call f2, it's at top-level scope
console.log how_many_times_functions_have_been_called # 3, refers to top-level scope
console.log x? # false, x does not exist at top_level scope
