User:JulienDethurens/Scripts/Heading code

This is code I often put at the top of my code (that's why this page is called "Heading code", btw).

It contains many useful functions, many that I designed for making libraries easier to create.

Variables

The code creates a variable that makes accessing the Terrain object easier, that variable is called "Terrain".

It also creates many variables for some services that I commonly use:

• Players
• StarterPack
• StarterGui
• Lighting
• Debris
• Teams
• BadgeService
• InsertService

local Players = Game:GetService('Players')
local StarterPack = Game:GetService('StarterPack')
local StarterGui = Game:GetService('StarterGui')
local Lighting = Game:GetService('Lighting')
local Debris = Game:GetService('Debris')
local Teams = Game:GetService('Teams')
local BadgeService = Game:GetService('BadgeService')
local InsertService = Game:GetService('InsertService')
local Terrain = Workspace.Terrain

is_a(value, data_type)

Parameters

Name	Type	Description
value		The value you want to check the type of.
data_type	string	The type you want to check for.

This function returns true if value is of type data_type. Otherwise, it returns false.

It supports the following types: Lua types, Instance types, Enum types, Enum, Color3, BrickColor, Vector2, Vector3, CFrame/CoordinateFrame, UDim, UDim2, RBXScriptSignal, Axes, Faces, Ray.

Just as a note, you can't use a "fake" value to make it return true with a value that is similar to a real value of the correct data type. If it says that the value is of the correct data type, then the value is of the correct data type.

local function is_a(value, data_type)
	-- Supported types: Lua types, Instance types, Enum types, Enum, Color3, BrickColor, Vector2, Vector3, CFrame/CoordinateFrame, UDim, UDim2, RBXScriptSignal, Axes, Faces, Ray
	-- Will return false if the type is not supported, even though the value might be of that type.
	-- This function can not be fooled by a fake value. If it says the value is a ClickDetector, then it IS a ClickDetector.
	-- This function uses a variety of ugly hacks that were found by JulienDethurens.
	-- I wish ROBLOX just provided an official way to do this, I wouldn't have to use lots of unrealiable ways to get the info I need... :/

	-- Here is a nice collection of bad practices, ugly hacks, and other things you should never use, but that you don't have the choice of using, because of ROBLOX's lack of an official way to distinguish data types:
	if type(value) == data_type then return true end -- Lua types
	if pcall(function() assert(Game.IsA(value, data_type)) end) then return true end -- Instance types
	if pcall(function() assert(Enum[data_type]) end) then -- Enum types
		for _, enum in next, Enum[data_type]:GetEnumItems() do
			if value == enum then
				return true
			end
		end
	elseif pcall(Enum.Material.GetEnumItems, value) then
		for _, enum in next, value:GetEnumItems() do
			if value == enum then
				return true
			end
		end
	end
	if data_type == 'Color3' and pcall(function() Instance.new('Color3Value').Value = value end) then return true -- Color3
	elseif data_type == 'BrickColor' and pcall(function() Instance.new('BrickColorValue').Value = value end) then return true -- BrickColor
	elseif data_type == 'Vector2' and pcall(function() return Vector2.new() + value end) then return true -- Vector2
	elseif data_type == 'Vector3' and pcall(function() Instance.new('Vector3Value').Value = value end) then return true -- Vector3
	elseif (data_type == 'CFrame' or data_type == 'CoordinateFrame') and pcall(function() Instance.new('CFrameValue').Value = value end) then return true -- CFrame
	elseif data_type == 'UDim' and pcall(function() return UDim.new() + value end) then return true -- UDim
	elseif data_type == 'UDim2' and pcall(function() Instance.new('Frame').Position = value end) then return true -- UDim2
	elseif data_type == 'Ray' and pcall(function() Ray.new(Vector3.new(), Vector3.new()).Distance(value, Vector3.new()) end) then return true -- Ray
	elseif data_type == 'Axes' and pcall(function() Instance.new('ArcHandles').Axes = value end) then return true -- Axes
	elseif data_type == 'Faces' and pcall(function() Instance.new('Handles').Faces = value end) then return true -- Faces
	elseif data_type == 'Enum' and pcall(Enum.Material.GetEnumItems, value) then return true -- Enum
	elseif data_type == 'RBXScriptSignal' then
		local _, connection = pcall(function() return Game.AllowedGearTypeChanged.connect(value) end)
		if _ and connection then
			connection:disconnect()
			return true
		end
	end
	return false
end

get_type(value)

Parameters

Name	Type	Description
value		The value you want to get the type of.

This function returns the most specific type it can get for a certain value. It supports all the types supported by the is_a function.

local function get_type(value)
	-- Returns the most specific type it can return. Supports the same types as the is_a function, except the enum types.
	if is_a(value, 'Instance') then return value.ClassName
	elseif is_a(value, 'Enum') then return 'Enum'
	elseif is_a(value, 'Color3') then return 'Color3'
	elseif is_a(value, 'BrickColor') then return 'BrickColor'
	elseif is_a(value, 'Vector2') then return 'Vector2'
	elseif is_a(value, 'Vector3') then return 'Vector3'
	elseif is_a(value, 'CFrame') then return 'CFrame'
	elseif is_a(value, 'UDim') then return 'UDim'
	elseif is_a(value, 'UDim2') then return 'UDim2'
	elseif is_a(value, 'Ray') then return 'Ray'
	elseif is_a(value, 'Axes') then return 'Axes'
	elseif is_a(value, 'Faces') then return 'Faces'
	elseif is_a(value, 'RBXScriptSignal') then return 'RBXScriptSignal'
	else return type(value)
	end
end

verify_arg(value, data_type, arg_num, func_name, optional)

Parameters

Name	Type	Description
value		The value you want the verify the type of.
data_type	string	The data type the value should be of.
arg_num	number	The № of the arg. Used in the error message.
func_name	string	The name of the function. Used in the error message.
optional	boolean	Whether the argument is optional or not. If true, the value nil will also be accepted.

This function will check if value is of type data_type. If not, it will print an error message:

bad argument #arg_num to func_name (data_type expected, got [the type of the argument, found with the get_type function]).

Use it in functions that receive arguments to check if arguments are of the correct type. Using this function can make debugging a lot easier (trust me, that's from experience).

local function verify_arg(value, data_type, arg_num, func_name, optional)
	-- Makes the function that called the calling function error, with an error message relating to a wrong type. Supports the same types as the is_a function.
	-- Also supports coercion for the number and string types.
	-- Returns the value, as it might be automatically converted if a coercion has been done.
	if type(data_type) ~= 'string' then error("bad argument #2 to 'verify_arg' (string expected, got " .. type(data_type) .. ")", 2) end
	if tonumber(arg_num) then
		arg_num = tonumber(arg_num)
	else
		error("bad argument #3 to 'verify_arg' (number expected, got " .. type(arg_num) .. ")")
	end
	if type(func_name) ~= 'string' then error("bad argument #4 to 'verify_arg' (string expected, got " .. type(func_name) .. ")") end

	if optional and value == nil then
		return value
	elseif is_a(value, data_type) then
		return value
	elseif data_type == 'number' and tonumber(value) then
		return tonumber(value)
	elseif data_type == 'string' and type(value) == 'number' then
		return tostring(value)
	else
		error("bad argument #" .. arg_num .. " to " .. func_name .. " (" .. data_type .. " expected, got " .. get_type(value) .. ")", 3)
	end
end

modify(instance, t)

Parameters

Name	Type	Description
instance	Instance	The instance you want to edit.
t	table	The changes you want to make to instance.

This function allows you to edit the properties and the hierarchy of a certain object. Because I am too lazy to explain exactly how it works, and because you already have the code anyways, I will only give you an example:

local part = modify(Instance.new('Part'), {
	Name = "Wall";
	Position = Vector3.new(10, 50, 10);
	with (Instance.new('Fire')) {
		Heat = 10;
		Size = 50;
	};
})

That code creates a part, sets its name to "Wall", sets its position to a certain Vector3, creates a Fire object in it, sets some of the properties of that Fire object, and stores the part in the part variable.

local function modify(instance, t)
	verify_arg(instance, 'Instance', 1, "modify")
	verify_arg(t, 'table', 2, "modify")
	for key, value in next, t do
		if type(key) == 'number' then
			value.Parent = instance 
		else
			instance[key] = value
		end
	end
	return instance
end

call_on_descendants(object, func)

Parameters

Name	Type	Description
object	Instance	The object you want to call a function on all the descendants of.
func	function	The function you want to call on all the descendants of the object.

This function calls func on all the descendants of object, including object itself.

local function call_on_descendants(object, func)
	-- Calls 'func' on 'object' and all its descendants, with the object or descendant as argument.
	verify_arg(object, 'Instance', 1, "func")
	verify_arg(func, 'function', 2, "func")
	func(object)
	for _, child in next, object:GetChildren() do
		call_on_descendants(child, func)
	end
end

get_nearest_ancestor(object, class_name)

Parameters

Name	Type	Description
object	Instance	The object of which you want to find an ancestor.
class_name	string	The class name of the ancestor you want to find.

This function returns the nearest ancestor of object of type class_name in ascending order.

local function get_nearest_ancestor(object, class_name)
	-- Returns the nearest ancestor of a certain object which is of a certain type.
	local ancestor = object
	repeat
		ancestor = ancestor.Parent
		if ancestor == nil then
			return nil
		end
	until ancestor:IsA(class_name)
	return ancestor
end

The Code

This is the entirety of the code:

local Players = Game:GetService('Players')
local StarterPack = Game:GetService('StarterPack')
local StarterGui = Game:GetService('StarterGui')
local Lighting = Game:GetService('Lighting')
local Debris = Game:GetService('Debris')
local Teams = Game:GetService('Teams')
local BadgeService = Game:GetService('BadgeService')
local InsertService = Game:GetService('InsertService')
local Terrain = Workspace.Terrain

local function is_a(value, data_type)
	-- Supported types: Lua types, Instance types, Enum types, Enum, Color3, BrickColor, Vector2, Vector3, CFrame/CoordinateFrame, UDim, UDim2, RBXScriptSignal, Axes, Faces, Ray
	-- Will return false if the type is not supported, even though the value might be of that type.
	-- This function can not be fooled by a fake value. If it says the value is a ClickDetector, then it IS a ClickDetector.
	-- This function uses a variety of ugly hacks that were found by JulienDethurens.
	-- I wish ROBLOX just provided an official way to do this, I wouldn't have to use lots of unrealiable ways to get the info I need... :/

	-- Here is a nice collection of bad practices, ugly hacks, and other things you should never use, but that you don't have the choice of using, because of ROBLOX's lack of an official way to distinguish data types:
	if type(value) == data_type then return true end -- Lua types
	if pcall(function() assert(Game.IsA(value, data_type)) end) then return true end -- Instance types
	if pcall(function() assert(Enum[data_type]) end) then -- Enum types
		for _, enum in next, Enum[data_type]:GetEnumItems() do
			if value == enum then
				return true
			end
		end
	elseif pcall(Enum.Material.GetEnumItems, value) then
		for _, enum in next, value:GetEnumItems() do
			if value == enum then
				return true
			end
		end
	end
	if data_type == 'Color3' and pcall(function() Instance.new('Color3Value').Value = value end) then return true -- Color3
	elseif data_type == 'BrickColor' and pcall(function() Instance.new('BrickColorValue').Value = value end) then return true -- BrickColor
	elseif data_type == 'Vector2' and pcall(function() return Vector2.new() + value end) then return true -- Vector2
	elseif data_type == 'Vector3' and pcall(function() Instance.new('Vector3Value').Value = value end) then return true -- Vector3
	elseif (data_type == 'CFrame' or data_type == 'CoordinateFrame') and pcall(function() Instance.new('CFrameValue').Value = value end) then return true -- CFrame
	elseif data_type == 'UDim' and pcall(function() return UDim.new() + value end) then return true -- UDim
	elseif data_type == 'UDim2' and pcall(function() Instance.new('Frame').Position = value end) then return true -- UDim2
	elseif data_type == 'Ray' and pcall(function() Ray.new(Vector3.new(), Vector3.new()).Distance(value, Vector3.new()) end) then return true -- Ray
	elseif data_type == 'Axes' and pcall(function() Instance.new('ArcHandles').Axes = value end) then return true -- Axes
	elseif data_type == 'Faces' and pcall(function() Instance.new('Handles').Faces = value end) then return true -- Faces
	elseif data_type == 'Enum' and pcall(Enum.Material.GetEnumItems, value) then return true -- Enum
	elseif data_type == 'RBXScriptSignal' then
		local _, connection = pcall(function() return Game.AllowedGearTypeChanged.connect(value) end)
		if _ and connection then
			connection:disconnect()
			return true
		end
	end
	return false
end

local function get_type(value)
	-- Returns the most specific type it can return. Supports the same types as the is_a function, except the enum types.
	if is_a(value, 'Instance') then return value.ClassName
	elseif is_a(value, 'Enum') then return 'Enum'
	elseif is_a(value, 'Color3') then return 'Color3'
	elseif is_a(value, 'BrickColor') then return 'BrickColor'
	elseif is_a(value, 'Vector2') then return 'Vector2'
	elseif is_a(value, 'Vector3') then return 'Vector3'
	elseif is_a(value, 'CFrame') then return 'CFrame'
	elseif is_a(value, 'UDim') then return 'UDim'
	elseif is_a(value, 'UDim2') then return 'UDim2'
	elseif is_a(value, 'Ray') then return 'Ray'
	elseif is_a(value, 'Axes') then return 'Axes'
	elseif is_a(value, 'Faces') then return 'Faces'
	elseif is_a(value, 'RBXScriptSignal') then return 'RBXScriptSignal'
	else return type(value)
	end
end

local function verify_arg(value, data_type, arg_num, func_name, optional)
	-- Makes the function that called the calling function error, with an error message relating to a wrong type. Supports the same types as the is_a function.
	-- Also supports coercion for the number and string types.
	-- Returns the value, as it might be automatically converted if a coercion has been done.
	if type(data_type) ~= 'string' then error("bad argument #2 to 'verify_arg' (string expected, got " .. type(data_type) .. ")", 2) end
	if tonumber(arg_num) then
		arg_num = tonumber(arg_num)
	else
		error("bad argument #3 to 'verify_arg' (number expected, got " .. type(arg_num) .. ")")
	end
	if type(func_name) ~= 'string' then error("bad argument #4 to 'verify_arg' (string expected, got " .. type(func_name) .. ")") end

	if optional and value == nil then
		return value
	elseif is_a(value, data_type) then
		return value
	elseif data_type == 'number' and tonumber(value) then
		return tonumber(value)
	elseif data_type == 'string' and type(value) == 'number' then
		return tostring(value)
	else
		error("bad argument #" .. arg_num .. " to " .. func_name .. " (" .. data_type .. " expected, got " .. get_type(value) .. ")", 3)
	end
end

local function modify(instance, t)
	verify_arg(instance, 'Instance', 1, "modify")
	verify_arg(t, 'table', 2, "modify")
	for key, value in next, t do
		if type(key) == 'number' then
			value.Parent = instance 
		else
			instance[key] = value
		end
	end
	return instance
end

local function call_on_descendants(object, func)
	-- Calls 'func' on 'object' and all its descendants, with the object or descendant as argument.
	verify_arg(object, 'Instance', 1, "func")
	verify_arg(func, 'function', 2, "func")
	func(object)
	for _, child in next, object:GetChildren() do
		call_on_descendants(child, func)
	end
end

local function get_nearest_ancestor(object, class_name)
	-- Returns the nearest ancestor of a certain object which is of a certain type.
	local ancestor = object
	repeat
		ancestor = ancestor.Parent
		if ancestor == nil then
			return nil
		end
	until ancestor:IsA(class_name)
	return ancestor
end