Merge remote-tracking branch 'origin/master'

assert.lua

@@ -3,6 +3,7 @@
 		- avoid garbage generation upon success,
 		- build nice formatted error messages
 		- post one level above the call site by default
+		- return their first argument so they can be used inline
 
 	default call is builtin global assert
 
@@ -23,16 +24,18 @@ local function _extra(msg)
 	if not msg then
 		return ""
 	end
-	return "(note: " .. msg .. ")"
+	return "\n\n\t(note: " .. msg .. ")"
 end
 
 --assert a value is not nil
+--return the value, so this can be chained
 function assert:some(v, msg, stack_level)
 	if v == nil then
 		error(("assertion failed: value is nil %s"):format(
 			_extra(msg)
 		), 2 + (stack_level or 0))
 	end
+	return v
 end
 
 --assert two values are equal
@@ -44,6 +47,7 @@ function assert:equal(a, b, msg, stack_level)
 			_extra(msg)
 		), 2 + (stack_level or 0))
 	end
+	return a
 end
 
 --assert two values are not equal
@@ -53,6 +57,7 @@ function assert:not_equal(a, b, msg, stack_level)
 			_extra(msg)
 		), 2 + (stack_level or 0))
 	end
+	return a
 end
 
 --assert a value is of a certain type
@@ -65,15 +70,19 @@ function assert:type(a, t, msg, stack_level)
 			_extra(msg)
 		), 2 + (stack_level or 0))
 	end
+	return a
 end
 
---replace everything in assert with nop functions, for near-zero overhead on release
+--replace everything in assert with nop functions that just return their second argument, for near-zero overhead on release
 function assert:nop()
+	local nop = function(self, a)
+		return a
+	end
 	setmetatable(self, {
-		__call = function() end,
+		__call = nop,
 	})
 	for k, v in pairs(self) do
-		self[k] = function() end
+		self[k] = nop
 	end
 end
 

init.lua

@@ -20,7 +20,7 @@ local _batteries = {
 	tablex = require_relative("tablex"),
 	stringx = require_relative("stringx"),
 	--sorting routines
-	stable_sort = require_relative("stable_sort"),
+	sort = require_relative("sort"),
 	--
 	functional = require_relative("functional"),
 	--collections
@@ -43,7 +43,7 @@ for _, alias in ipairs({
 	{"mathx", "math"},
 	{"tablex", "table"},
 	{"stringx", "string"},
-	{"stable_sort", "sort"},
+	{"sort", "stable_sort"},
 	{"colour", "color"},
 }) do
 	_batteries[alias[2]] = _batteries[alias[1]]
@@ -61,7 +61,7 @@ function _batteries:export()
 	self.tablex.overlay(table, self.tablex)
 	--now we can use it through table directly
 	table.overlay(table, self.functional)
-	self.stable_sort:export()
+	self.sort:export()
 
 	--functional module also available separate from table
 	functional = self.functional

readme.md

@@ -10,22 +10,26 @@ Examples [in another repo](https://github.com/1bardesign/batteries-examples) to
 
 # Module Overview
 
-- `class` - Single-inheritance oo in a single function.
+**Lua Core Extensions:**
 - `mathx` - Mathematical extensions. Alias `math`.
 - `tablex` - Table handling extensions. Alias `table`.
 - `stringx` - String handling extensions. Alias `string`.
-- `stable_sort` - A stable sorting algorithm that is also, as a bonus, often faster than table.sort under luajit.
+**General Utility:**
+- `class` - Single-inheritance oo in a single function.
 - `functional` - Functional programming facilities. `map`, `reduce`, `any`, `match`, `minmax`, `mean`...
-- `sequence` - An oo wrapper on sequential tables, so you can do `t:insert(i, v)` instead of `table.insert(t, i, v)`. Also supports method chaining for the `functional` interface above, which can save a lot of typing!
+- `sequence` - An oo wrapper on sequential tables, so you can do `t:insert(i, v)` instead of `table.insert(t, i, v)`. Also supports method chaining for the `functional` interface above, which can save a lot of needless typing!
 - `set` - A set type supporting a full suite of set operations with fast membership testing and ipairs-style iteration.
+- `sort` - Provides a stable merge+insertion sorting algorithm that is also, as a bonus, often faster than `table.sort` under luajit. Also exposes `insertion_sort` if needed. Alias `stable_sort`
 - `state_machine` - Finite state machine implementation with state transitions and all the rest. Useful for game states, ai, cutscenes...
-- `async` - Async operations as coroutines.
-- `manual_gc` - Get GC out of your update/draw calls. Useful when trying to get accurate profiling information; moves "randomness" of GC. Requires you to think a bit about your garbage budgets though.
-- `colour` - Colour conversion routines. Alias `color`.
-- `unique_mapping` - Generate a unique mapping from arbitrary lua values to numeric keys - essentially making up a consistent ordering for unordered data. Niche, but can be used to optimise draw batches for example, as you can't sort on textures without it.
+**Geometry:**
+- `intersect` - 2d intersection routines, a bit sparse at the moment
 - `vec2` - 2d vectors with method chaining, garbage saving interface. A bit of a mouthful at times, but you get used to it.
 - `vec3` - 3d vectors as above.
-- `intersect` - 2d intersection routines, a bit sparse at the moment
+**Misc:**
+- `async` - Async operations as coroutines.
+- `colour` - Colour conversion routines. Alias `color`.
+- `manual_gc` - Get GC out of your update/draw calls. Useful when trying to get accurate profiling information; moves "randomness" of GC. Requires you to think a bit about your garbage budgets though.
+- `unique_mapping` - Generate a unique mapping from arbitrary lua values to numeric keys - essentially making up a consistent ordering for unordered data. Niche, but can be used to optimise draw batches for example, as you can't sort on textures without it.
 
 Aliases are provided at both the `batteries` level and globally when exported.
 

sequence.lua

@@ -9,6 +9,7 @@ local path = (...):gsub("sequence", "")
 local class = require(path .. "class")
 local table = require(path .. "tablex") --shadow global table module
 local functional = require(path .. "functional")
+local stable_sort = require(path .. "sort").stable_sort
 
 local sequence = class(table) --proxy missing table fns to tablex api
 
@@ -17,29 +18,34 @@ function sequence:new(t)
 	return self:init(t or {})
 end
 
---alias
-sequence.join = table.concat
-
---sorting default to stable if present
-sequence.sort = table.stable_sort or table.sort
+--sorting default to stable
+sequence.sort = stable_sort
 
 --patch various interfaces in a type-preserving way, for method chaining
 
 --import copying tablex
 function sequence:keys()
-	return sequence(self:keys())
+	return sequence(table.keys(self))
 end
 
 function sequence:values()
-	return sequence(self:values())
-end
-
-function sequence:append(other)
-	return sequence(self:append(other))
+	return sequence(table.values(self))
 end
 
 function sequence:dedupe()
-	return sequence(self:dedupe())
+	return sequence(table.dedupe(self))
+end
+
+function sequence:append(...)
+	return sequence(table.append(self, ...))
+end
+
+function sequence:overlay(...)
+	return sequence(table.overlay(self, ...))
+end
+
+function sequence:copy(...)
+	return sequence(table.copy(self, ...))
 end
 
 --import functional interface

sort.lua

@@ -1,9 +1,9 @@
 --[[
-	stable sorting routines
+	various sorting routines
 ]]
 
---this is based on MIT licensed code from Dirk Laurie and Steve Fisher
---license as follows:
+--this is based on code from Dirk Laurie and Steve Fisher,
+--used under license as follows:
 
 --[[
 	Copyright © 2013 Dirk Laurie and Steve Fisher.
@@ -29,13 +29,13 @@
 
 -- (modifications by Max Cahill 2018, 2020)
 
-local sort_core = {}
+local sort = {}
 
 --tunable size for insertion sort "bottom out"
-sort_core.max_chunk_size = 32
+sort.max_chunk_size = 32
 
 --insertion sort on a section of array
-function sort_core._insertion_sort_impl(array, first, last, less)
+function sort._insertion_sort_impl(array, first, last, less)
 	for i = first + 1, last do
 		local k = first
 		local v = array[i]
@@ -52,7 +52,7 @@ function sort_core._insertion_sort_impl(array, first, last, less)
 end
 
 --merge sorted adjacent sections of array
-function sort_core._merge(array, workspace, low, middle, high, less)
+function sort._merge(array, workspace, low, middle, high, less)
 	local i, j, k
 	i = 1
 	-- copy first half of array to auxiliary array
@@ -85,14 +85,14 @@ function sort_core._merge(array, workspace, low, middle, high, less)
 end
 
 --implementation for the merge sort
-function sort_core._merge_sort_impl(array, workspace, low, high, less)
-	if high - low <= sort_core.max_chunk_size then
-		sort_core._insertion_sort_impl(array, low, high, less)
+function sort._merge_sort_impl(array, workspace, low, high, less)
+	if high - low <= sort.max_chunk_size then
+		sort._insertion_sort_impl(array, low, high, less)
 	else
 		local middle = math.floor((low + high) / 2)
-		sort_core._merge_sort_impl(array, workspace, low, middle, less)
-		sort_core._merge_sort_impl(array, workspace, middle + 1, high, less)
-		sort_core._merge(array, workspace, low, middle, high, less)
+		sort._merge_sort_impl(array, workspace, low, middle, less)
+		sort._merge_sort_impl(array, workspace, middle + 1, high, less)
+		sort._merge(array, workspace, low, middle, high, less)
 	end
 end
 
@@ -102,7 +102,7 @@ local function default_less(a, b)
 end
 
 --inline common setup stuff
-function sort_core._sort_setup(array, less)
+function sort._sort_setup(array, less)
 	--default less
 	less = less or default_less
 	--
@@ -119,36 +119,36 @@ function sort_core._sort_setup(array, less)
 	return trivial, n, less
 end
 
-function sort_core.stable_sort(array, less)
+function sort.stable_sort(array, less)
 	--setup
-	local trivial, n, less = sort_core._sort_setup(array, less)
+	local trivial, n, less = sort._sort_setup(array, less)
 	if not trivial then
 		--temp storage; allocate ahead of time
 		local workspace = {}
 		local middle = math.ceil(n / 2)
 		workspace[middle] = array[1]
 		--dive in
-		sort_core._merge_sort_impl( array, workspace, 1, n, less )
+		sort._merge_sort_impl( array, workspace, 1, n, less )
 	end
 	return array
 end
 
-function sort_core.insertion_sort(array, less)
+function sort.insertion_sort(array, less)
 	--setup
-	local trivial, n, less = sort_core._sort_setup(array, less)
+	local trivial, n, less = sort._sort_setup(array, less)
 	if not trivial then
-		sort_core._insertion_sort_impl(array, 1, n, less)
+		sort._insertion_sort_impl(array, 1, n, less)
 	end
 	return array
 end
 
-sort_core.unstable_sort = table.sort
+sort.unstable_sort = table.sort
 
 --export sort core to the global table module
-function sort_core:export()
-	table.insertion_sort = sort_core.insertion_sort
-	table.stable_sort = sort_core.stable_sort
-	table.unstable_sort = sort_core.unstable_sort
+function sort:export()
+	table.insertion_sort = sort.insertion_sort
+	table.stable_sort = sort.stable_sort
+	table.unstable_sort = sort.unstable_sort
 end
 
-return sort_core
+return sort

state_machine.lua

@@ -12,6 +12,10 @@
 	on draw, the current state's draw callback is called
 
 	TODO: consider coroutine friendliness
+
+	TODO: consider refactoring the callback signatures to allow using objects with methods
+	      like update(dt)/draw() directly
+	      current pattern means they need to be wrapped (as in :as_state())
 ]]
 
 local path = (...):gsub("state_machine", "")
@@ -41,12 +45,27 @@ end
 --make an internal call
 function state_machine:_call(name, ...)
 	local state = self:_get_state()
-	if state and type(state[name]) == "function" then
+	if state then
+		if type(state[name]) == "function" then
 			return state[name](self, state, ...)
+		elseif type(state) == "function" then
+			return state(self, name, ...)
+		end
 	end
 	return nil
 end
 
+--make an internal call and transition if the return value is a valid state
+--return the value if it isn't a valid state
+function state_machine:_call_and_transition(name, ...)
+	local r = self:_call(name, ...)
+	if self:has_state(r) then
+		self:set_state(r, r == self.current_state)
+		return nil
+	end
+	return r
+end
+
 -------------------------------------------------------------------------------
 --various checks
 
@@ -63,7 +82,7 @@ end
 
 --add a state
 function state_machine:add_state(name, data)
-	if self.has_state(name) then
+	if self:has_state(name) then
 		error("error: added duplicate state "..name)
 	else
 		self.states[name] = data
@@ -77,7 +96,7 @@ end
 
 --remove a state
 function state_machine:remove_state(name)
-	if not self.has_state(name) then
+	if not self:has_state(name) then
 		error("error: removed missed state "..name)
 	else
 		if self:in_state(name) then
@@ -99,13 +118,13 @@ function state_machine:replace_state(name, data, do_transitions)
 	end
 	self.states[name] = data
 	if do_transitions and current then
-		self:_call("enter")
+		self:_call_and_transition("enter")
 	end
 
 	return self
 end
 
---ensure a state doesn't exist
+--ensure a state doesn't exist; transition out of it if we're currently in it
 function state_machine:clear_state(name)
 	return self:replace_state(name, nil, true)
 end
@@ -113,23 +132,52 @@ end
 -------------------------------------------------------------------------------
 --transitions and updates
 
+--set the current state
+--if the enter callback of the target state returns a valid state name, then
+--	it is transitioned to in turn, and so on until the machine is at rest
 function state_machine:set_state(state, reset)
 	if self.current_state ~= state or reset then
 		self:_call("exit")
 		self.current_state = state
-		self:_call("enter")
+		self:_call_and_transition("enter")
 	end
 	return self
 end
 
 --perform an update
 --pass in an optional delta time which is passed as an arg to the state functions
+--if the state update returns a string, and we have that state
+--	then we change state (reset if it's the current state)
+--	and return nil
+--otherwise, the result is returned
 function state_machine:update(dt)
-	return self:_call("update", dt)
+	return self:_call_and_transition("update", dt)
 end
 
+--draw the current state
 function state_machine:draw()
 	self:_call("draw")
 end
 
+--wrap a state machine in a table suitable for use directly as a state in another state_machine
+--upon entry, this machine will be forced into enter_state
+--the parent will be accessible under m.parent
+function state_machine:as_state(enter_state)
+	if not self._as_state then
+		self._as_state = {
+			enter = function(m, s)
+				self.parent = m
+				self:set_state(enter_state)
+			end,
+			update = function(m, s, dt)
+				return self:update(dt)
+			end,
+			draw = function(m, s)
+				return self:draw()
+			end,
+		}
+	end
+	return self._as_state
+end
+
 return state_machine