pHook creates callable arrays of functions.
local pHook = require("p_hook")
local hooks = pHook.newHookList()
table.insert(hooks, function(color) if color == "violet" then return 1 end end)
table.insert(hooks, function(color) if color == "viridian" then return 2 end end)
table.insert(hooks, function(color) if color == "vermillian" then return 3 end end)
hooks("viridian") --> 2
hooks("blue") --> nilAPI
pHook.callHooks
The __call metamethod for calling hooks in forward order.
local a,b,c,d = pHook.callHooks(hl, ...)-
hl: The calling HookList. -
…: Arguments for the hooks.
Returns: Up to four return values provided by a successful hook, or nil.
pHook.callHooksBack
The __call metamethod for calling hooks in backward order.
local a,b,c,d = pHook.callHooks(hl, ...)-
hl: The calling HookList. -
…: Arguments for the hooks.
Returns: Up to four return values provided by a successful hook, or nil.
pHook.newHookList
Creates a new HookList array.
local hooks = pHook.newHookList([back])-
[back]: When true, the HookList will iterate backwards by default when called ashooks(…).
Returns: The new HookList.
pHook.wrap
Returns a function that calls a HookList. May be useful in cases where a function expects a function (and not a table) as an argument.
local fn = pHook.wrap(hl)-
hl: The HookList.
Returns: A function that calls the HookList.
Module Notes
HookLists
A HookList is an array with an attached __call metamethod. The array contains hooks (functions). When a list is called like a function, the hooks are executed in order, stopping when any hook returns a non-nil value.
An optional filter function may be assigned to index 0. When present, the hooks will only be processed if the filter returns a truthy value.
The filter’s return value is not propagated anywhere: its only purpose is to tell the hook caller whether or not it’s OK to proceed.
Overriding the order of evaluation
To run a HookList in a specific order (regardless of how it was created with pHook.newHookList()), just call pHook.callHooks(hl, …) or pHook.callHooksBack(hl, …). This unfortunately does not work with HookLists that are wrapped into functions.
VERSION: 2.106