Playdate code snippets

lua_amendments.lua

-- Tiny snippet to bring a sort-of `require` functionality,
-- where return values of a module (or pdz files in this case)
-- will be cached, and the file only be run once.
-- After `import`ing this file in your main file, you can use `require` similar to how you would in basic Lua.
-- This also adds convenience wrappers around `playdate.file.load()` and `playdate.file.run()`,
-- to pose as `loadfile()` and `dofile()` respectively.

local pd <const> = playdate


local function loadfile(pdzFile, ...)
  return pd.file.load(pdzFile, ...)
end
_G.loadfile = loadfile


local assert <const> = assert

local function dofile (filename)
  local f = assert(loadfile(filename))
  return f()
end
_G.dofile = dofile


local seen <const> = {}
local cache <const> = {}

local function require(pdzFile)
  print("Require: " .. pdzFile)
  if seen[pdzFile] then
    return cache[pdzFile]
  end
  local value = dofile(pdzFile)
  seen[pdzFile] = true
  cache[pdzFile] = value
  return value
end
_G.require = require

macros.fnl

; Fennel macro module which can be imported via `(import-macros ...)`

; creates a local that is tagged as a constant and can't be reassigned (which brings a bit more performance)
(fn const [name x]
  `(lua ,(.. "local " (tostring name) " <const> = " (tostring x))))

; Wrap a body of code in `gfx.pushContext(img) ... gfx.popContext()`.
; (Assumes that `playdate.graphics` is assigned to a local const named `gfx`)
(fn with-context [img ...]
  (let [tbl [`(gfx.pushContext ,img) ...]]
    (table.insert tbl `(gfx.popContext))
    `(do ,(unpack tbl))))

; Sample a body of code via `CoreLibs/utilities/sampler`
; (remember to import that library if you want to use this)
(fn sampling [sample-name ...]
  `(sample ,sample-name
     (fn [] ,...)))


{: const
 : with-context
 : sampling}