modlib/func.lua
2022-09-07 11:41:53 +02:00

149 lines
3.2 KiB
Lua

-- Localize globals
local error, coroutine, modlib, unpack, select, setmetatable
= error, coroutine, modlib, unpack, select, setmetatable
-- Set environment
local _ENV = {}
setfenv(1, _ENV)
no_op = function() end
function curry(func, ...)
local args = { ... }
return function(...) return func(unpack(args), ...) end
end
function curry_tail(func, ...)
local args = { ... }
return function(...) return func(unpack(modlib.table.concat({...}, args))) end
end
function curry_full(func, ...)
local args = { ... }
return function() return func(unpack(args)) end
end
function args(...)
local args = { ... }
return function(func) return func(unpack(args)) end
end
function value(val) return function() return val end end
function values(...)
local args = { ... }
return function() return unpack(args) end
end
function memoize(func)
return setmetatable({}, {
__index = function(self, key)
local value = func(key)
self[key] = value
return value
end,
__call = function(self, arg)
return self[arg]
end,
__mode = "k"
})
end
-- Equivalent to `for x, y, z in iterator, state, ... do callback(x, y, z) end`
function iterate(callback, iterator, state, ...)
local function loop(...)
if ... == nil then return end
callback(...)
return loop(iterator(state, ...))
end
return loop(iterator(state, ...))
end
function for_generator(caller, ...)
local co = coroutine.create(function(...)
return caller(function(...)
return coroutine.yield(...)
end, ...)
end)
local args = {...}
return function()
if coroutine.status(co) == "dead" then
return
end
local function _iterate(status, ...)
if not status then
error((...))
end
return ...
end
return _iterate(coroutine.resume(co, unpack(args)))
end
end
-- Does not use select magic, stops at the first nil value
function aggregate(binary_func, total, ...)
if total == nil then return end
local function _aggregate(value, ...)
if value == nil then return end
total = binary_func(total, value)
return _aggregate(...)
end
_aggregate(...)
return total
end
function override_chain(func, override)
return function(...)
func(...)
return override(...)
end
end
--+ Calls func using the provided arguments, deepcopies all arguments
function call_by_value(func, ...)
return func(unpack(modlib.table.deepcopy{...}))
end
-- Functional wrappers for Lua's builtin metatable operators (arithmetic, concatenation, length, comparison, indexing, call)
function add(a, b) return a + b end
function mul(a, b) return a * b end
function div(a, b) return a / b end
function mod(a, b) return a % b end
function pow(a, b) return a ^ b end
function unm(a) return -a end
function concat(a, b) return a .. b end
function len(a) return #a end
function eq(a, b) return a == b end
function lt(a, b) return a < b end
function le(a, b) return a <= b end
function index(object, key) return object[key] end
function newindex(object, key, value) object[key] = value end
function call(object, ...) object(...) end
-- Functional wrappers for logical operators, suffixed with _ for syntactical convenience
function not_(a) return not a end
_ENV["not"] = not_
function and_(a, b) return a and b end
_ENV["and"] = and_
function or_(a, b) return a or b end
_ENV["or"] = or_
-- Export environment
return _ENV