module Main where

import Data.Monoid ((<>))
import Data.Text (Text)
import qualified Data.Text as Text

import Codec.Beam.Instructions
import qualified Codec.Beam as Beam
import qualified Eunit


main :: IO ()
main =
  Eunit.run
    [ Eunit.test "loads_empty"
        [ Beam.insertModuleInfo ]
        [ "?assertMatch({module, loads_empty}, code:load_file(loads_empty))"
        , "?assertEqual(erlang:get_module_info(loads_empty), loads_empty:module_info())"
        , "?assertEqual(erlang:get_module_info(loads_empty, attributes), loads_empty:module_info(attributes))"
        ]
        []

    -- From beam_asm: 
    , withConstant "number_five" id (5 :: Int)
    , withConstant "number_one_thousand" id (5 :: Int)
    , withConstant "number_two_thousand_forty_seven" id (2047 :: Int)
    , withConstant "number_two_thousand_forty_eight" id (2048 :: Int)
    , withConstant "number_negative_one" id (-1 :: Int)
    , withConstant "number_large_negative" id (-4294967295 :: Int)
    , withConstant "number_large_positive" id (4294967295 :: Int)
    , withConstant "number_very_large_positive" id (429496729501 :: Int)

    -- Atom table encodings
    , withConstant "arbitrary_atom" id ("hello" :: Text)
    , withConstant "module_name_atom" id ("module_name_atom" :: Text)
    , withConstant_ "constant_nil" Beam.Nil "[]"

    -- Comparisons
    , Eunit.test "is_equal"
        [ Beam.export "test" 2 ]
        [ "?assertNot(is_equal:test(2, 3))"
        , "?assertNot(is_equal:test(2.0, 3))"
        , "?assert(is_equal:test(2.0, 2))"
        , "?assert(is_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_eq
    , Eunit.test "is_not_equal"
        [ Beam.export "test" 2 ]
        [ "?assert(is_not_equal:test(2, 3))"
        , "?assert(is_not_equal:test(2.0, 3))"
        , "?assertNot(is_not_equal:test(2.0, 2))"
        , "?assertNot(is_not_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_ne
    , Eunit.test "is_exactly_equal"
        [ Beam.export "test" 2 ]
        [ "?assertNot(is_exactly_equal:test(2, 3))"
        , "?assertNot(is_exactly_equal:test(2.0, 3))"
        , "?assertNot(is_exactly_equal:test(2.0, 2))"
        , "?assert(is_exactly_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_eq_exact
    , Eunit.test "is_not_exactly_equal"
        [ Beam.export "test" 2 ]
        [ "?assert(is_not_exactly_equal:test(2, 3))"
        , "?assert(is_not_exactly_equal:test(2.0, 3))"
        , "?assert(is_not_exactly_equal:test(2.0, 2))"
        , "?assertNot(is_not_exactly_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_ne_exact
    , Eunit.test "is_less_than"
        [ Beam.export "test" 2 ]
        [ "?assert(is_less_than:test(5, 6))"
        , "?assertNot(is_less_than:test(6, 5))"
        , "?assertNot(is_less_than:test(5.0, 5))"
        , "?assertNot(is_less_than:test(6.0, 5.0))"
        ]
        $ withCmp is_lt
    , Eunit.test "is_greater_than_or_equal"
        [ Beam.export "test" 2 ]
        [ "?assertNot(is_greater_than_or_equal:test(5, 6))"
        , "?assert(is_greater_than_or_equal:test(6, 5))"
        , "?assert(is_greater_than_or_equal:test(5.0, 5))"
        , "?assert(is_greater_than_or_equal:test(6.0, 5.0))"
        ]
        $ withCmp is_ge

    -- Literal table encodings
    , withConstant_ "atom" (Beam.Atom "hiya") "hiya"
    , withConstant_ "float" (Beam.Float 3.1415) "3.1415"
    , withConstant_ "bitstring" (Beam.Binary "teapot") "<<\"teapot\">>"
    , withConstant_ "empty_tuple" (Beam.Tuple []) "{}"
    , withConstant_ "small_tuple" (Beam.Tuple [Beam.Integer 1]) "{1}"
    , withConstant_ "empty_list" (Beam.List []) "[]"
    , withConstant_ "small_list" (Beam.List [Beam.Integer 4, Beam.Integer 5]) "[4, 5]"
    , withConstant_ "empty_map" (Beam.Map []) "#{}"
    , withConstant_ "small_map" (Beam.Map [(Beam.Atom "a", Beam.Integer 1), (Beam.Atom "b", Beam.Integer 2)]) "#{a=>1,b=>2}"

    , Eunit.test "large_tuple"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(300, tuple_size(large_tuple:test()))"
        , "?assertEqual(300, element(300, large_tuple:test()))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.Tuple (map Beam.Integer [1..300])) (Beam.X 0)
        , return'
        ]

    , Eunit.test "multiple_literals"
        [ Beam.export "test" 0 ]
        [ "?assert(multiple_literals:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.Atom "dummy") (Beam.X 0)
        , move (Beam.Atom "true") (Beam.X 0)
        , return'
        ]

    , Eunit.test "call_into_identity"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(1023, call_into_identity:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.Integer 1023) (Beam.X 0)
        , call_only 1 (Beam.Label 4)
        , return'
        , label (Beam.Label 3)
        , func_info "identity" 1
        , label (Beam.Label 4)
        , return'
        ]

    -- Type checks
    , Eunit.test "is_nil"
        [ Beam.export "test" 1 ]
        [ "?assert(is_nil:test([]))"
        , "?assertNot(is_nil:test(23))"
        , "?assertNot(is_nil:test([23]))"
        ]
        $ withType is_nil
    , Eunit.test "is_list"
        [ Beam.export "test" 1 ]
        [ "?assert(is_list:test([]))"
        , "?assertNot(is_list:test(23))"
        , "?assert(is_list:test([23]))"
        ]
        $ withType is_list
    , Eunit.test "is_nonempty_list"
        [ Beam.export "test" 1 ]
        [ "?assertNot(is_nonempty_list:test([]))"
        , "?assertNot(is_nonempty_list:test(23))"
        , "?assert(is_nonempty_list:test([23]))"
        ]
        $ withType is_nonempty_list
    , Eunit.test "is_map"
        [ Beam.export "test" 1 ]
        [ "?assert(is_map:test(#{}))"
        , "?assertNot(is_map:test(23))"
        , "?assert(is_map:test(#{a=>23}))"
        ]
        $ withType is_map

    -- Based on /#x_and_y_regs_in_memory
    , Eunit.test "allocate_for_call_fun"
        [ Beam.export "apply2" 3 ]
        [ "_add = fun 'erlang':'+'/2"
        , "?assertEqual(4, allocate_for_call_fun:apply2(2, 2, _add))"
        ]
        [ label (Beam.Label 1)
        , func_info "apply2" 3
        , label (Beam.Label 2)
        , allocate 2 3
        , move (Beam.X 2) (Beam.Y 1)
        , move (Beam.X 1) (Beam.Y 0)
        , call 1 (Beam.Label 4)
        , move (Beam.X 0) (Beam.X 1)
        , move (Beam.Y 0) (Beam.X 0)
        , move (Beam.X 1) (Beam.Y 0)
        , call 1 (Beam.Label 4)
        , move (Beam.Y 1) (Beam.X 2)
        , move (Beam.X 0) (Beam.X 1)
        , move (Beam.Y 0) (Beam.X 0)
        , call_fun 2
        , deallocate 2
        , return'
        , label (Beam.Label 3)
        , func_info "identity" 1
        , label (Beam.Label 4)
        , return'
        ]

    , Eunit.test "external_fun"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(3, (external_fun:test())(1, 2))" ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.ExternalFun (Beam.Import "erlang" "+" 2)) (Beam.X 0)
        , return'
        ]

    , Eunit.test "get_tuple_element"
        [ Beam.export "first" 1
        , Beam.export "second" 1
        ]
        [ "?assertEqual(2, get_tuple_element:first({2}))"
        , "?assertEqual(hi, get_tuple_element:second({oh, hi, there}))"
        ]
        [ label (Beam.Label 1)
        , func_info "first" 1
        , label (Beam.Label 2)
        , get_tuple_element (Beam.X 0) 0 (Beam.X 0)
        , return'
        , label (Beam.Label 3)
        , func_info "second" 1
        , label (Beam.Label 4)
        , get_tuple_element (Beam.X 0) 1 (Beam.X 0)
        , return'
        ]

    , Eunit.test "set_tuple_element"
        [ Beam.export "make" 1 ]
        [ "?assertEqual({dream, work}, set_tuple_element:make({team, work}))"
        ]
        [ label (Beam.Label 1)
        , func_info "make" 1
        , label (Beam.Label 2)
        , set_tuple_element ("dream" :: Text) (Beam.X 0) 0
        , return'
        ]

    , Eunit.test "put_list"
        [ Beam.export "test" 0 ]
        [ "?assertEqual([one, 2], put_list:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , put_list (Beam.Integer 2) Beam.Nil (Beam.X 0)
        , put_list ("one" :: Text) (Beam.X 0) (Beam.X 0)
        , return'
        ]

    , Eunit.test "make_a_tuple"
        [ Beam.export "test" 0 ]
        [ "?assertEqual({one, 2}, make_a_tuple:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , put_tuple (2 :: Int) (Beam.X 0)
        , put ("one" :: Text)
        , put (2 :: Int)
        , return'
        ]

    , Eunit.test "make_a_map"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(#{a=>1, 2=>b}, make_a_map:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , put_map_assoc (Beam.Label 0) (Beam.Map []) (Beam.X 0)
            [ (Beam.toSource (Beam.Atom "a"), Beam.toSource (1 :: Int))
            , (Beam.toSource (2 :: Int), Beam.toSource (Beam.Atom "b"))
            ]
        , return'
        ]

    , Eunit.test "get_from_map"
        [ Beam.export "test" 2 ]
        [ "?assertEqual(5, get_from_map:test(#{a=>5}, a))"
        , "?assertEqual(error, get_from_map:test(#{}, a))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 2
        , label (Beam.Label 2)
        , get_map_elements (Beam.Label 3) (Beam.X 0)
            [ (Beam.toSource (Beam.X 1), Beam.toRegister (Beam.X 0))
            ]
        , return'
        , label (Beam.Label 3)
        , move ("error" :: Text) (Beam.X 0)
        , return'
        ]

    , Eunit.test "get_da_list"
        [ Beam.export "second" 1 ]
        [ "?assertEqual(2, get_da_list:second([1,2,3]))"
        ]
        [ label (Beam.Label 1)
        , func_info "second" 1
        , label (Beam.Label 2)
        , get_list (Beam.X 0) (Beam.X 1) (Beam.X 0)
        , get_list (Beam.X 0) (Beam.X 0) (Beam.X 1)
        , return'
        ]

    , Eunit.test "jumping_around"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(yay, jumping_around:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , jump (Beam.Label 4)
        , label (Beam.Label 3)
        , move ("yay" :: Text) (Beam.X 0)
        , return'
        , label (Beam.Label 4)
        , jump (Beam.Label 3)
        ]

    , Eunit.test "simple_lambda"
        [ Beam.export "test" 1 ]
        [ "?assertEqual(to_capture, (simple_lambda:test(to_capture))())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 1
        , label (Beam.Label 2)
        , make_fun2 (Beam.Lambda "lambda_function" 0 (Beam.Label 4) 1)
        , return'
        , label (Beam.Label 3)
        , func_info "backing_function" 1
        , label (Beam.Label 4)
        , return'
        ]

    , Eunit.test "external_call"
        [ Beam.export "test" 2 ]
        [ "?assertEqual(3, external_call:test(1, 2))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 2
        , label (Beam.Label 2)
        , call_ext_only (Beam.Import "erlang" "+" 2)
        , return'
        ]

    , Eunit.test "float_math"
        [ Beam.export "sum" 2 ]
        [ "?assertEqual(5.0, float_math:sum(2, 3.0))"
        ]
        [ label (Beam.Label 1)
        , func_info "sum" 2
        , label (Beam.Label 2)
        , fconv (Beam.X 0) (Beam.F 0)
        , fmove (Beam.X 1) (Beam.F 1)
        , fclearerror
        , fadd (Beam.F 0) (Beam.F 1) (Beam.F 0)
        , fmove (Beam.F 0) (Beam.X 0)
        , return'
        ]

    , Eunit.test "destinations"
        [ Beam.export "test" 1 ]
        [ "?assertEqual(four, destinations:test(4))"
        , "?assertEqual(five, destinations:test(5))"
        , "?assertEqual(neither, destinations:test(6))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 1
        , label (Beam.Label 2)
        , select_val (Beam.X 0) (Beam.Label 3)
            [ (Beam.Label 4, Beam.toSource (4 :: Int))
            , (Beam.Label 5, Beam.toSource (5 :: Int))
            ]
        , label (Beam.Label 3)
        , move ("neither" :: Text) (Beam.X 0)
        , return'
        , label (Beam.Label 4)
        , move ("four" :: Text) (Beam.X 0)
        , return'
        , label (Beam.Label 5)
        , move ("five" :: Text) (Beam.X 0)
        , return'
        ]
    ]



-- HELPERS
  Having these in one spot makes it easier to see the pain - points in the API .
  I imagine that some of these will eventually live in a utility module within src/.


withConstant_ :: Beam.IsSource s => String -> s -> String -> Eunit.Test
withConstant_ name term =
  withConstant name (const term)


withConstant :: (Erlang a, Beam.IsSource s) => String -> (a -> s) -> a -> Eunit.Test
withConstant name toSource value =
  Eunit.test name
    [ Beam.export "check" 0 ]
    [ "?assertEqual(" <> erlang value <> ", " <> name <> ":check())"
    ]
    [ label (Beam.Label 1)
    , func_info "check" 0
    , label (Beam.Label 2)
    , move (toSource value) (Beam.X 0)
    , return'
    ]

withCmp :: (Beam.Label -> Beam.X -> Beam.X -> Beam.Op) -> [Beam.Op]
withCmp toOp =
  jumpFunction 2 $ \i -> toOp i (Beam.X 0) (Beam.X 1)


withType :: (Beam.Label -> Beam.X -> Beam.Op) -> [Beam.Op]
withType toOp =
  jumpFunction 1 $ \i -> toOp i (Beam.X 0)


jumpFunction :: Int -> (Beam.Label -> Beam.Op) -> [Beam.Op]
jumpFunction args decision =
  [ label (Beam.Label 1)
  , func_info "test" args
  , label (Beam.Label 2)
  , decision (Beam.Label 3)
  , move ("true" :: Text) (Beam.X 0)
  , return'
  , label (Beam.Label 3)
  , move ("false" :: Text) (Beam.X 0)
  , return'
  ]



  PRINT ERLANG LITERALS


class Erlang a where
  erlang :: a -> String

instance Erlang a => Erlang [a] where
  erlang = mconcat . map erlang

instance Erlang Text where
  erlang = Text.unpack

instance Erlang Int where
  erlang = erlang . show

instance Erlang Char where
  erlang x = [x]

 From beam_asm: 
 Atom table encodings
 Comparisons
 Literal table encodings
 Type checks
 Based on /#x_and_y_regs_in_memory
 HELPERS
module Main where

import Data.Monoid ((<>))
import Data.Text (Text)
import qualified Data.Text as Text

import Codec.Beam.Instructions
import qualified Codec.Beam as Beam
import qualified Eunit


main :: IO ()
main =
  Eunit.run
    [ Eunit.test "loads_empty"
        [ Beam.insertModuleInfo ]
        [ "?assertMatch({module, loads_empty}, code:load_file(loads_empty))"
        , "?assertEqual(erlang:get_module_info(loads_empty), loads_empty:module_info())"
        , "?assertEqual(erlang:get_module_info(loads_empty, attributes), loads_empty:module_info(attributes))"
        ]
        []

    , withConstant "number_five" id (5 :: Int)
    , withConstant "number_one_thousand" id (5 :: Int)
    , withConstant "number_two_thousand_forty_seven" id (2047 :: Int)
    , withConstant "number_two_thousand_forty_eight" id (2048 :: Int)
    , withConstant "number_negative_one" id (-1 :: Int)
    , withConstant "number_large_negative" id (-4294967295 :: Int)
    , withConstant "number_large_positive" id (4294967295 :: Int)
    , withConstant "number_very_large_positive" id (429496729501 :: Int)

    , withConstant "arbitrary_atom" id ("hello" :: Text)
    , withConstant "module_name_atom" id ("module_name_atom" :: Text)
    , withConstant_ "constant_nil" Beam.Nil "[]"

    , Eunit.test "is_equal"
        [ Beam.export "test" 2 ]
        [ "?assertNot(is_equal:test(2, 3))"
        , "?assertNot(is_equal:test(2.0, 3))"
        , "?assert(is_equal:test(2.0, 2))"
        , "?assert(is_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_eq
    , Eunit.test "is_not_equal"
        [ Beam.export "test" 2 ]
        [ "?assert(is_not_equal:test(2, 3))"
        , "?assert(is_not_equal:test(2.0, 3))"
        , "?assertNot(is_not_equal:test(2.0, 2))"
        , "?assertNot(is_not_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_ne
    , Eunit.test "is_exactly_equal"
        [ Beam.export "test" 2 ]
        [ "?assertNot(is_exactly_equal:test(2, 3))"
        , "?assertNot(is_exactly_equal:test(2.0, 3))"
        , "?assertNot(is_exactly_equal:test(2.0, 2))"
        , "?assert(is_exactly_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_eq_exact
    , Eunit.test "is_not_exactly_equal"
        [ Beam.export "test" 2 ]
        [ "?assert(is_not_exactly_equal:test(2, 3))"
        , "?assert(is_not_exactly_equal:test(2.0, 3))"
        , "?assert(is_not_exactly_equal:test(2.0, 2))"
        , "?assertNot(is_not_exactly_equal:test(2.0, 2.0))"
        ]
        $ withCmp is_ne_exact
    , Eunit.test "is_less_than"
        [ Beam.export "test" 2 ]
        [ "?assert(is_less_than:test(5, 6))"
        , "?assertNot(is_less_than:test(6, 5))"
        , "?assertNot(is_less_than:test(5.0, 5))"
        , "?assertNot(is_less_than:test(6.0, 5.0))"
        ]
        $ withCmp is_lt
    , Eunit.test "is_greater_than_or_equal"
        [ Beam.export "test" 2 ]
        [ "?assertNot(is_greater_than_or_equal:test(5, 6))"
        , "?assert(is_greater_than_or_equal:test(6, 5))"
        , "?assert(is_greater_than_or_equal:test(5.0, 5))"
        , "?assert(is_greater_than_or_equal:test(6.0, 5.0))"
        ]
        $ withCmp is_ge

    , withConstant_ "atom" (Beam.Atom "hiya") "hiya"
    , withConstant_ "float" (Beam.Float 3.1415) "3.1415"
    , withConstant_ "bitstring" (Beam.Binary "teapot") "<<\"teapot\">>"
    , withConstant_ "empty_tuple" (Beam.Tuple []) "{}"
    , withConstant_ "small_tuple" (Beam.Tuple [Beam.Integer 1]) "{1}"
    , withConstant_ "empty_list" (Beam.List []) "[]"
    , withConstant_ "small_list" (Beam.List [Beam.Integer 4, Beam.Integer 5]) "[4, 5]"
    , withConstant_ "empty_map" (Beam.Map []) "#{}"
    , withConstant_ "small_map" (Beam.Map [(Beam.Atom "a", Beam.Integer 1), (Beam.Atom "b", Beam.Integer 2)]) "#{a=>1,b=>2}"

    , Eunit.test "large_tuple"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(300, tuple_size(large_tuple:test()))"
        , "?assertEqual(300, element(300, large_tuple:test()))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.Tuple (map Beam.Integer [1..300])) (Beam.X 0)
        , return'
        ]

    , Eunit.test "multiple_literals"
        [ Beam.export "test" 0 ]
        [ "?assert(multiple_literals:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.Atom "dummy") (Beam.X 0)
        , move (Beam.Atom "true") (Beam.X 0)
        , return'
        ]

    , Eunit.test "call_into_identity"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(1023, call_into_identity:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.Integer 1023) (Beam.X 0)
        , call_only 1 (Beam.Label 4)
        , return'
        , label (Beam.Label 3)
        , func_info "identity" 1
        , label (Beam.Label 4)
        , return'
        ]

    , Eunit.test "is_nil"
        [ Beam.export "test" 1 ]
        [ "?assert(is_nil:test([]))"
        , "?assertNot(is_nil:test(23))"
        , "?assertNot(is_nil:test([23]))"
        ]
        $ withType is_nil
    , Eunit.test "is_list"
        [ Beam.export "test" 1 ]
        [ "?assert(is_list:test([]))"
        , "?assertNot(is_list:test(23))"
        , "?assert(is_list:test([23]))"
        ]
        $ withType is_list
    , Eunit.test "is_nonempty_list"
        [ Beam.export "test" 1 ]
        [ "?assertNot(is_nonempty_list:test([]))"
        , "?assertNot(is_nonempty_list:test(23))"
        , "?assert(is_nonempty_list:test([23]))"
        ]
        $ withType is_nonempty_list
    , Eunit.test "is_map"
        [ Beam.export "test" 1 ]
        [ "?assert(is_map:test(#{}))"
        , "?assertNot(is_map:test(23))"
        , "?assert(is_map:test(#{a=>23}))"
        ]
        $ withType is_map

    , Eunit.test "allocate_for_call_fun"
        [ Beam.export "apply2" 3 ]
        [ "_add = fun 'erlang':'+'/2"
        , "?assertEqual(4, allocate_for_call_fun:apply2(2, 2, _add))"
        ]
        [ label (Beam.Label 1)
        , func_info "apply2" 3
        , label (Beam.Label 2)
        , allocate 2 3
        , move (Beam.X 2) (Beam.Y 1)
        , move (Beam.X 1) (Beam.Y 0)
        , call 1 (Beam.Label 4)
        , move (Beam.X 0) (Beam.X 1)
        , move (Beam.Y 0) (Beam.X 0)
        , move (Beam.X 1) (Beam.Y 0)
        , call 1 (Beam.Label 4)
        , move (Beam.Y 1) (Beam.X 2)
        , move (Beam.X 0) (Beam.X 1)
        , move (Beam.Y 0) (Beam.X 0)
        , call_fun 2
        , deallocate 2
        , return'
        , label (Beam.Label 3)
        , func_info "identity" 1
        , label (Beam.Label 4)
        , return'
        ]

    , Eunit.test "external_fun"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(3, (external_fun:test())(1, 2))" ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , move (Beam.ExternalFun (Beam.Import "erlang" "+" 2)) (Beam.X 0)
        , return'
        ]

    , Eunit.test "get_tuple_element"
        [ Beam.export "first" 1
        , Beam.export "second" 1
        ]
        [ "?assertEqual(2, get_tuple_element:first({2}))"
        , "?assertEqual(hi, get_tuple_element:second({oh, hi, there}))"
        ]
        [ label (Beam.Label 1)
        , func_info "first" 1
        , label (Beam.Label 2)
        , get_tuple_element (Beam.X 0) 0 (Beam.X 0)
        , return'
        , label (Beam.Label 3)
        , func_info "second" 1
        , label (Beam.Label 4)
        , get_tuple_element (Beam.X 0) 1 (Beam.X 0)
        , return'
        ]

    , Eunit.test "set_tuple_element"
        [ Beam.export "make" 1 ]
        [ "?assertEqual({dream, work}, set_tuple_element:make({team, work}))"
        ]
        [ label (Beam.Label 1)
        , func_info "make" 1
        , label (Beam.Label 2)
        , set_tuple_element ("dream" :: Text) (Beam.X 0) 0
        , return'
        ]

    , Eunit.test "put_list"
        [ Beam.export "test" 0 ]
        [ "?assertEqual([one, 2], put_list:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , put_list (Beam.Integer 2) Beam.Nil (Beam.X 0)
        , put_list ("one" :: Text) (Beam.X 0) (Beam.X 0)
        , return'
        ]

    , Eunit.test "make_a_tuple"
        [ Beam.export "test" 0 ]
        [ "?assertEqual({one, 2}, make_a_tuple:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , put_tuple (2 :: Int) (Beam.X 0)
        , put ("one" :: Text)
        , put (2 :: Int)
        , return'
        ]

    , Eunit.test "make_a_map"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(#{a=>1, 2=>b}, make_a_map:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , put_map_assoc (Beam.Label 0) (Beam.Map []) (Beam.X 0)
            [ (Beam.toSource (Beam.Atom "a"), Beam.toSource (1 :: Int))
            , (Beam.toSource (2 :: Int), Beam.toSource (Beam.Atom "b"))
            ]
        , return'
        ]

    , Eunit.test "get_from_map"
        [ Beam.export "test" 2 ]
        [ "?assertEqual(5, get_from_map:test(#{a=>5}, a))"
        , "?assertEqual(error, get_from_map:test(#{}, a))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 2
        , label (Beam.Label 2)
        , get_map_elements (Beam.Label 3) (Beam.X 0)
            [ (Beam.toSource (Beam.X 1), Beam.toRegister (Beam.X 0))
            ]
        , return'
        , label (Beam.Label 3)
        , move ("error" :: Text) (Beam.X 0)
        , return'
        ]

    , Eunit.test "get_da_list"
        [ Beam.export "second" 1 ]
        [ "?assertEqual(2, get_da_list:second([1,2,3]))"
        ]
        [ label (Beam.Label 1)
        , func_info "second" 1
        , label (Beam.Label 2)
        , get_list (Beam.X 0) (Beam.X 1) (Beam.X 0)
        , get_list (Beam.X 0) (Beam.X 0) (Beam.X 1)
        , return'
        ]

    , Eunit.test "jumping_around"
        [ Beam.export "test" 0 ]
        [ "?assertEqual(yay, jumping_around:test())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 0
        , label (Beam.Label 2)
        , jump (Beam.Label 4)
        , label (Beam.Label 3)
        , move ("yay" :: Text) (Beam.X 0)
        , return'
        , label (Beam.Label 4)
        , jump (Beam.Label 3)
        ]

    , Eunit.test "simple_lambda"
        [ Beam.export "test" 1 ]
        [ "?assertEqual(to_capture, (simple_lambda:test(to_capture))())"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 1
        , label (Beam.Label 2)
        , make_fun2 (Beam.Lambda "lambda_function" 0 (Beam.Label 4) 1)
        , return'
        , label (Beam.Label 3)
        , func_info "backing_function" 1
        , label (Beam.Label 4)
        , return'
        ]

    , Eunit.test "external_call"
        [ Beam.export "test" 2 ]
        [ "?assertEqual(3, external_call:test(1, 2))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 2
        , label (Beam.Label 2)
        , call_ext_only (Beam.Import "erlang" "+" 2)
        , return'
        ]

    , Eunit.test "float_math"
        [ Beam.export "sum" 2 ]
        [ "?assertEqual(5.0, float_math:sum(2, 3.0))"
        ]
        [ label (Beam.Label 1)
        , func_info "sum" 2
        , label (Beam.Label 2)
        , fconv (Beam.X 0) (Beam.F 0)
        , fmove (Beam.X 1) (Beam.F 1)
        , fclearerror
        , fadd (Beam.F 0) (Beam.F 1) (Beam.F 0)
        , fmove (Beam.F 0) (Beam.X 0)
        , return'
        ]

    , Eunit.test "destinations"
        [ Beam.export "test" 1 ]
        [ "?assertEqual(four, destinations:test(4))"
        , "?assertEqual(five, destinations:test(5))"
        , "?assertEqual(neither, destinations:test(6))"
        ]
        [ label (Beam.Label 1)
        , func_info "test" 1
        , label (Beam.Label 2)
        , select_val (Beam.X 0) (Beam.Label 3)
            [ (Beam.Label 4, Beam.toSource (4 :: Int))
            , (Beam.Label 5, Beam.toSource (5 :: Int))
            ]
        , label (Beam.Label 3)
        , move ("neither" :: Text) (Beam.X 0)
        , return'
        , label (Beam.Label 4)
        , move ("four" :: Text) (Beam.X 0)
        , return'
        , label (Beam.Label 5)
        , move ("five" :: Text) (Beam.X 0)
        , return'
        ]
    ]



  Having these in one spot makes it easier to see the pain - points in the API .
  I imagine that some of these will eventually live in a utility module within src/.


withConstant_ :: Beam.IsSource s => String -> s -> String -> Eunit.Test
withConstant_ name term =
  withConstant name (const term)


withConstant :: (Erlang a, Beam.IsSource s) => String -> (a -> s) -> a -> Eunit.Test
withConstant name toSource value =
  Eunit.test name
    [ Beam.export "check" 0 ]
    [ "?assertEqual(" <> erlang value <> ", " <> name <> ":check())"
    ]
    [ label (Beam.Label 1)
    , func_info "check" 0
    , label (Beam.Label 2)
    , move (toSource value) (Beam.X 0)
    , return'
    ]

withCmp :: (Beam.Label -> Beam.X -> Beam.X -> Beam.Op) -> [Beam.Op]
withCmp toOp =
  jumpFunction 2 $ \i -> toOp i (Beam.X 0) (Beam.X 1)


withType :: (Beam.Label -> Beam.X -> Beam.Op) -> [Beam.Op]
withType toOp =
  jumpFunction 1 $ \i -> toOp i (Beam.X 0)


jumpFunction :: Int -> (Beam.Label -> Beam.Op) -> [Beam.Op]
jumpFunction args decision =
  [ label (Beam.Label 1)
  , func_info "test" args
  , label (Beam.Label 2)
  , decision (Beam.Label 3)
  , move ("true" :: Text) (Beam.X 0)
  , return'
  , label (Beam.Label 3)
  , move ("false" :: Text) (Beam.X 0)
  , return'
  ]



  PRINT ERLANG LITERALS


class Erlang a where
  erlang :: a -> String

instance Erlang a => Erlang [a] where
  erlang = mconcat . map erlang

instance Erlang Text where
  erlang = Text.unpack

instance Erlang Int where
  erlang = erlang . show

instance Erlang Char where
  erlang x = [x]
