-- Translate Yhc Core primitives to Erlang BIFs and runtime-provided
-- functions.

module Yhc.Core.BackEnd.Erlang.TransPrim where

import Data.Char
import Data.Maybe
import qualified Data.Map as M
import Yhc.Core.Extra

import Yhc.Core.BackEnd.Erlang.TT.Ecore
import Yhc.Core.BackEnd.Erlang.TT.Ebif
import Yhc.Core.BackEnd.Erlang.CorePrep

prim2bifAnno :: CoreFunc -> CoreAnnotations -> Maybe BifSpec

prim2bifAnno cf anno = prim2bif cf

prim2bif :: CoreFunc -> Maybe BifSpec

prim2bif (CorePrim {coreFuncName = "MUL_W"}) = isBif "*"
prim2bif (CorePrim {coreFuncName = "ADD_W"}) = isBif "+"
prim2bif (CorePrim {coreFuncName = "SUB_W"}) = isBif "-"
prim2bif (CorePrim {coreFuncName = "LE_W" }) = isBif "<="
prim2bif (CorePrim {coreFuncName = "LT_W" }) = isBif "<"
prim2bif (CorePrim {coreFuncName = "GT_W" }) = isBif ">"
prim2bif (CorePrim {coreFuncName = "GE_W" }) = isBif ">="
prim2bif (CorePrim {coreFuncName = "EQ_W" }) = isBif "=="
prim2bif (CorePrim {coreFuncName = "NE_W" }) = isBif "=/="
prim2bif (CorePrim {coreFuncName = "NEG_W" }) = Just ("erlang", "-", 1)

prim2bif (CorePrim {coreFuncName = "MUL_L"}) = isBif "*"
prim2bif (CorePrim {coreFuncName = "ADD_L"}) = isBif "+"
prim2bif (CorePrim {coreFuncName = "SUB_L"}) = isBif "-"
prim2bif (CorePrim {coreFuncName = "LE_L" }) = isBif "<="
prim2bif (CorePrim {coreFuncName = "LT_L" }) = isBif "<"
prim2bif (CorePrim {coreFuncName = "GT_L" }) = isBif ">"
prim2bif (CorePrim {coreFuncName = "GE_L" }) = isBif ">="
prim2bif (CorePrim {coreFuncName = "EQ_L" }) = isBif "=="
prim2bif (CorePrim {coreFuncName = "NE_L" }) = isBif "=/="
prim2bif (CorePrim {coreFuncName = "NEG_L" }) = Just ("erlang", "-", 1)

prim2bif (CorePrim {coreFuncName = "EQ_C" }) = isBif "=="

prim2bif (CorePrim {coreFuncName = "THROW_E" }) = Just ("erlang", "throw", 1)

-- All primitives not listed above, and belonging to the Normal Set
-- are expected to be implemented in Erlang in the module "yc2erl".
-- Since original names of primitives are uppercased, they are lowercased
-- in the Erlang implementation. That is, CMP_W corresponds to
-- yc2erl:cmp_w

prim2bif (CorePrim {coreFuncName = pn}) | pn `M.member` normPrimSpecMap =
  let (_:_:_:arity:_) = fromJust $ M.lookup pn normPrimSpecMap
  in  Just ("yc2erl", map toLower pn, read arity)

prim2bif z = error $ "prim2bif: primitive " ++ show z ++ " does not belong to the Normal Set " ++
  "nor does it have proper annotation"