Update: I'm not using Neovim any longer, so this is here mostly for posterity.

Functions that allow you to call a function not more than once in a given timeframe.

This can be illustrated with timing diagrams. In the following diagrams, f designates call to the throttled function, t is the period where the timer is running, and x shows you the actual execution point of the throttled function.

Using the arguments of the first function call while the timer was running (the default).

f 1  2  3  4  5  6
t -------- --------
x 1--      4--

In this case, the function f was called 6 times. f's timer t was started on the first invocation of f, and stopped shortly after the third invocation, taking 8 'ticks'. During this run of the timer, the function f was executed only once –– at the beginning (leading edge) --, taking 3 ticks to execute. This is then repeated for function invocations 4 through 6.

You can use the test_defer() function from this module to show you an example that corresponds to the timing diagrams. Its invocation and output will look something like this:

:lua require'throttle-debounce'.test_defer('tl')
" tl: 1
" 1
" 2
" 3
" tl: 4
" 4
" 5
" 6

Again, using the arguments of the first function call while the timer was running (the default).

f 1  2  3    4  5  6
t --------   --------
x         1--        4--

:lua require'throttle-debounce'.test_defer('tt')`
" 1
" 2
" 3
" tt: 1
" 4
" 5
" 6
" tt: 4

Using the arguments of the last call while the timer was running:

f 1  2  3    4  5  6
t --------   --------
x         3--        6--

:lua require'throttle-debounce'.test_defer('tt', true)`
" 1
" 2
" 3
" tt: 3
" 4
" 5
" 6
" tt: 6

On each function call, the timer is reset (indicated by an r):

f 1  2  3  4  5  6
t ---r--r--r--r--r-------
x 1--

:lua require'throttle-debounce'.test_defer('dl')
" dl: 1
" 1
" 2
" 3
" 4
" 5
" 6

Using the arguments of the last function call while the timer was running (the default).

f 1  2  3  4  5  6
t ---r--r--r--r--r-------
x                        6--

:lua require'throttle-debounce'.test_defer('dt')
" 1
" 2
" 3
" 4
" 5
" 6
" (pause, press <cr>)
" dt: 6

Using the arguments of the first function call while the timer was running.

f 1  2  3  4  5  6
t ---r--r--r--r--r-------
x                        1--

:lua require'throttle-debounce'.test_defer('dt', true)
" 1
" 2
" 3
" 4
" 5
" 6
" (pause, press <cr>)
" dt: 1