shithub: MicroHs

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Check for multiple definitions in EBinds

--- a/src/MicroHs/Expr.hs

+++ b/src/MicroHs/Expr.hs

@@ -8,7 +8,7 @@

   Expr(..), showExpr,

   Listish(..),

   Lit(..), showLit, eqLit,

-  EBind(..),

+  EBind(..), showEBind,

   Eqn(..),

   EStmt(..),

   EAlts(..),

--- a/src/MicroHs/Parse.hs

+++ b/src/MicroHs/Parse.hs

@@ -380,9 +380,14 @@

 pEqns :: P (Ident, [Eqn])

 pEqns = P.do

-  (name, eqn@(Eqn ps _)) <- pEqn (\ _ _ -> True)

-  neqns <- emany (pSpec ';' *> pEqn (\ n l -> eqIdent n name && l == length ps))

-  P.pure (name, eqn : map snd neqns)

+  (name, eqn@(Eqn ps alts)) <- pEqn (\ _ _ -> True)

+  case (ps, alts) of

+    ([], EAlts [_] []) ->

+      -- don't collect equations when of the form 'i = e'

+      P.pure (name, [eqn])

+    _ -> P.do

+      neqns <- emany (pSpec ';' *> pEqn (\ n l -> eqIdent n name && l == length ps))

+      P.pure (name, eqn : map snd neqns)

 pEqn :: (Ident -> Int -> Bool) -> P (Ident, Eqn)

 pEqn test = P.do

--- a/src/MicroHs/TypeCheck.hs

+++ b/src/MicroHs/TypeCheck.hs

@@ -1183,8 +1183,7 @@

 tCheckPat t ap ta = T.do

 --  traceM $ "tcPat: " ++ show ap

   let vs = filter (not . isUnderscore) $ patVars ap

-  T.when (anySameBy eqIdent vs) $

-    tcError (getSLocIdent (head vs)) "Multiply defined"

+  multCheck vs

   env <- T.mapM (\ v -> (v,) <$> newUVar) vs

   withExtVals env $ T.do

     pp <- withTCMode TCPat $ tCheckExpr t ap

@@ -1191,6 +1190,12 @@

     () <- checkArity 0 pp

     ta pp

+multCheck :: [Ident] -> T ()

+multCheck vs =

+  T.when (anySameBy eqIdent vs) $ T.do

+    let v = head vs

+    tcError (getSLocIdent v) $ "Multiply defined: " ++ showIdent v

+

 checkArity :: Int -> EPat -> T ()

 checkArity n (EApp f a) = T.do

   checkArity (n+1) f

@@ -1222,6 +1227,7 @@

   let

     tmap = M.fromList [ (i, t) | BSign i t <- xbs ]

     xs = concatMap getBindVars xbs

+  multCheck xs

   xts <- T.mapM (tcBindVarT tmap) xs

   withExtVals xts $ T.do

     nbs <- T.mapM tcBind xbs

-- 

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