Fixture.hs

{-# LANGUAGE QuasiQuotes #-}

module Language.PureScript.Backend.Lua.Fixture where

import Data.String.Interpolate (__i)
import Language.PureScript.Backend.Lua.Name (Name, name, unsafeName)
import Language.PureScript.Backend.Lua.Name qualified as Name
import Language.PureScript.Backend.Lua.Types hiding (var)

--------------------------------------------------------------------------------
-- Hard-coded Lua pieces -------------------------------------------------------

uniqueName ∷ MonadState Natural m ⇒ Text → m Name
uniqueName prefix = do
  index ← get
  modify' (+ 1)
  pure $ unsafeName (prefix <> show index)

psluaName ∷ Name → Name
psluaName = Name.join2 [name|PSLUA|]

moduleName ∷ Name.Name
moduleName = [name|M|]

runtimeLazyName ∷ Name
runtimeLazyName = psluaName [name|runtime_lazy|]

runtimeLazy ∷ Statement
runtimeLazy =
  ForeignSourceStat
    [__i|
    local function #{Name.toText runtimeLazyName}(name)
      return function(init)
        return function()
          local state = 0
          local val = nil
          if state == 2 then
            return val
          else
            if state == 1 then
              return error(name .. " was needed before it finished initializing")
            else
              state = 1
              val = init()
              state = 2
              return val
            end
          end
        end
      end
    end
    |]

objectUpdateName ∷ Name
objectUpdateName = psluaName [name|object_update|]

objectUpdate ∷ Statement
objectUpdate =
  ForeignSourceStat
    [__i|
    local function #{Name.toText objectUpdateName}(o, patches)
      local o_copy = {}
      for k, v in pairs(o) do
        local patch_v = patches[k]
        if patch_v ~= nil then
          o_copy[k] = patch_v
        else
          o_copy[k] = v
        end
      end
      return o_copy
    end
    |]