Updated deps, removed Prim.undefined, no unused arguments.

Author: Unisay

flake.lock

@@ -5,9 +5,19 @@
     flake-utils.url = "github:numtide/flake-utils";
     easy-purescript-nix.url = "github:justinwoo/easy-purescript-nix";
   };
-  outputs = { self, nixpkgs, flake-utils, haskellNix, easy-purescript-nix }:
-    let supportedSystems = [ "x86_64-linux" ];
-    in flake-utils.lib.eachSystem supportedSystems (system:
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+      haskellNix,
+      easy-purescript-nix,
+    }:
+    let
+      supportedSystems = [ "x86_64-linux" ];
+    in
+    flake-utils.lib.eachSystem supportedSystems (
+      system:
       let
         easy-ps = easy-purescript-nix.packages.${system};
         pkgs = import nixpkgs {
@@ -21,49 +31,59 @@
               src = ./.;
               compiler-nix-name = "ghc98";
               evalSystem = "x86_64-linux";
-              modules = let prof = false;
-              in [{
-                doHaddock = false;
-                doHoogle = false;
-                enableProfiling = prof;
-                enableLibraryProfiling = prof;
-              }];
+              modules =
+                let
+                  prof = false;
+                in
+                [
+                  {
+                    doHaddock = false;
+                    doHoogle = false;
+                    enableProfiling = prof;
+                    enableLibraryProfiling = prof;
+                  }
+                ];
 
               name = "purescript-lua";
 
               shell = {
                 tools = {
-                  cabal = {};
-                  fourmolu = {};
-                  hlint = {};
-                  haskell-language-server = {};
+                  cabal = { };
+                  fourmolu = { };
+                  hlint = { };
+                  haskell-language-server = { };
                 };
                 buildInputs = with pkgs; [
                   cachix
-                  lua51Packages.lua
-                  lua51Packages.luacheck
                   easy-ps.purs-0_15_15
                   easy-ps.spago
+                  lua51Packages.lua
+                  lua51Packages.luacheck
+                  nil
                   treefmt
                   upx
                   yamlfmt
                 ];
               };
-
             };
           })
         ];
         flake = pkgs.psluaProject.flake { };
-      in flake // {
+      in
+      flake
+      // {
         legacyPackages = pkgs;
         packages.default = flake.packages."pslua:exe:pslua";
         packages.static = flake.ciJobs.x86_64-unknown-linux-musl.packages."pslua:exe:pslua";
-      });
+      }
+    );
 
   # --- Flake Local Nix Configuration ----------------------------
   nixConfig = {
-    extra-substituters =
-      [ "https://cache.iog.io" "https://purescript-lua.cachix.org" ];
+    extra-substituters = [
+      "https://cache.iog.io"
+      "https://purescript-lua.cachix.org"
+    ];
     extra-trusted-public-keys = [
       "hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ="
       "purescript-lua.cachix.org-1:yLs4ei2HtnuPtzLekOrW3xdfm95+Etw15gwgyIGTayA="

flake.nix

@@ -28,7 +28,6 @@ import Language.PureScript.PSString
   , decodeStringEscaping
   )
 import Relude.Extra (toFst)
-import Relude.Unsafe qualified as Unsafe
 import Text.Megaparsec qualified as Megaparsec
 import Text.Pretty.Simple (pShow)
 import Text.Show (Show (..))
@@ -135,7 +134,10 @@ useAnnotation name = do
 mkImports ∷ RepM [ModuleName]
 mkImports = do
   Cfn.Module {moduleName, moduleImports} ← gets contextModule
-  pure $ filter (isIncluded moduleName) (snd <$> moduleImports)
+  pure $
+    -- it's ok to always add prim as an explicit import:
+    -- DCE removes it if it's not used.
+    ModuleName "Prim" : [i | (_ann, i) ← moduleImports, isIncluded moduleName i]
  where
   isIncluded ∷ PS.ModuleName → ModuleName → Bool
   isIncluded currentModule modname = modname /= currentModule
@@ -170,7 +172,7 @@ collectDataDeclarations cfnModules = Map.unions do
             | bind ← Cfn.moduleBindings cfnModule
             , Cfn.Constructor _ann tyName ctorName fields ← boundExp bind
             ]
-      , let ty = fst (Unsafe.head ctors) -- groupBy never makes an empty group
+      , let ty = fst (head (NE.fromList ctors)) -- groupBy never makes an empty group
       , let algebraicType = if length ctors == 1 then ProductType else SumType
       ]
  where

lib/Language/PureScript/Backend/IR.hs

@@ -6,7 +6,7 @@ import Data.Graph (graphFromEdges', reverseTopSort)
 import Data.Map qualified as Map
 import Language.PureScript.Backend.IR.Inliner qualified as Inline
 import Language.PureScript.Backend.IR.Names
-  ( ModuleName
+  ( ModuleName (..)
   , Name (..)
   , PropName (PropName)
   , QName (QName)

lib/Language/PureScript/Backend/IR/Linker.hs

@@ -4,7 +4,6 @@ module Language.PureScript.Backend.Lua
   ( fromUberModule
   , fromIR
   , fromName
-  -- , qualifyName
   , qualifyName
   , Error (..)
   ) where
@@ -23,7 +22,7 @@ import Data.Traversable (for)
 import Language.PureScript.Backend.IR qualified as IR
 import Language.PureScript.Backend.IR.Linker (UberModule (..))
 import Language.PureScript.Backend.IR.Linker qualified as Linker
-import Language.PureScript.Backend.IR.Query (usesPrimModule, usesRuntimeLazy)
+import Language.PureScript.Backend.IR.Query (usesRuntimeLazy)
 import Language.PureScript.Backend.Lua.Fixture qualified as Fixture
 import Language.PureScript.Backend.Lua.Key qualified as Key
 import Language.PureScript.Backend.Lua.Linker.Foreign qualified as Foreign
@@ -32,7 +31,7 @@ import Language.PureScript.Backend.Lua.Name qualified as Name
 import Language.PureScript.Backend.Lua.Types (ParamF (..))
 import Language.PureScript.Backend.Lua.Types qualified as Lua
 import Language.PureScript.Backend.Types (AppOrModule (..))
-import Language.PureScript.Names (ModuleName, runModuleName)
+import Language.PureScript.Names (ModuleName (..), runModuleName)
 import Language.PureScript.Names qualified as PS
 import Path (Abs, Dir, Path)
 import Prelude hiding (exp, local)
@@ -82,13 +81,9 @@ fromUberModule foreigns needsRuntimeLazy appOrModule uber = (`evalStateT` 0) do
           recBinds ← forM (toList recGroup) \(IR.QName modname name, irExp) →
             (modname,name,) . asExpression
               <$> fromIR foreigns Set.empty modname irExp
-          let declarations = DList.fromList do
-                (modname, name, _exp) ← recBinds
-                pure $ mkBinding modname (fromName name) Lua.Nil
-              assignments = DList.fromList do
-                (modname, name, exp) ← recBinds
-                pure $ mkBinding modname (fromName name) exp
-          pure $ declarations <> assignments
+          pure $ DList.fromList do
+            (modname, name, exp) ← recBinds
+            pure $ mkBinding modname (fromName name) exp
 
     returnExp ←
       case appOrModule of
@@ -111,25 +106,19 @@ fromUberModule foreigns needsRuntimeLazy appOrModule uber = (`evalStateT` 0) do
       )
 
   pure . mconcat $
-    [ [Lua.assign moduleVar (Lua.table []) | not (null bindings)]
-    , [ mkBinding Fixture.primModule Fixture.undefined Lua.Nil
-      | usesPrimModule uber
-      ]
-    , [Fixture.runtimeLazy | untag needsRuntimeLazy && usesRuntimeLazy uber]
+    [ [Fixture.runtimeLazy | untag needsRuntimeLazy && usesRuntimeLazy uber]
     , [Fixture.objectUpdate | UsesObjectUpdate ← [usesObjectUpdate]]
+    , [Lua.local1 Fixture.moduleName (Lua.table []) | not (null bindings)]
     , toList (DList.snoc bindings returnStat)
     ]
 
 mkBinding ∷ ModuleName → Lua.Name → Lua.Exp → Lua.Statement
 mkBinding modname name =
   Lua.assign $
     Lua.VarField
-      (Lua.ann (Lua.var moduleVar))
+      (Lua.ann (Lua.varName Fixture.moduleName))
       (qualifyName modname name)
 
-moduleVar ∷ Lua.Var
-moduleVar = Lua.VarName [Lua.name|M|]
-
 asExpression ∷ Either Lua.Chunk Lua.Exp → Lua.Exp
 asExpression = \case
   Left chunk → Lua.chunkToExpression chunk
@@ -206,26 +195,29 @@ fromIR foreigns topLevelNames modname ir = case ir of
       Lua.functionCall (Lua.varName Fixture.objectUpdateName) [obj, vals]
   IR.Abs _ann param expr → do
     e ← goExp expr
-    luaParam ←
-      Lua.ParamNamed
-        <$> case param of
-          IR.ParamUnused _ann → uniqueName "unused"
-          IR.ParamNamed _ann name → pure (fromName name)
-    pure . Right $ Lua.functionDef [luaParam] [Lua.return e]
-  IR.App _ann expr param → do
+    let luaParams = case param of
+          IR.ParamUnused _ann → []
+          IR.ParamNamed _ann name → [ParamNamed (fromName name)]
+    pure . Right $ Lua.functionDef luaParams [Lua.return e]
+  IR.App _ann expr arg → do
     e ← goExp expr
-    a ← goExp param
-    pure . Right $ Lua.functionCall e [a]
+    Right . Lua.functionCall e <$> case arg of
+      -- PS sometimes inserts syntetic unused argument "Prim.undefined"
+      IR.Ref _ann (IR.Imported (IR.ModuleName "Prim") (IR.Name "undefined")) _ →
+        pure []
+      _ → goExp arg <&> \a → [a]
   IR.Ref _ann qualifiedName index →
     pure . Right $ case qualifiedName of
       IR.Local name
         | topLevelName ← qualifyName modname (fromName name)
         , Set.member topLevelName topLevelNames →
-            Lua.varField (Lua.var moduleVar) topLevelName
+            Lua.varField (Lua.varName Fixture.moduleName) topLevelName
       IR.Local name →
         Lua.varName (fromNameWithIndex name index)
       IR.Imported modname' name →
-        Lua.varField (Lua.var moduleVar) (qualifyName modname' (fromName name))
+        Lua.varField
+          (Lua.varName Fixture.moduleName)
+          (qualifyName modname' (fromName name))
   IR.Let _ann bindings bodyExp → do
     body ← go bodyExp
     recs ←
@@ -294,11 +286,5 @@ keyCtor = Lua.String "$ctor"
 --------------------------------------------------------------------------------
 -- Helpers ---------------------------------------------------------------------
 
-uniqueName ∷ MonadState Natural m ⇒ Text → m Lua.Name
-uniqueName prefix = do
-  index ← get
-  modify' (+ 1)
-  pure $ Lua.unsafeName (prefix <> show index)
-
 qualifyName ∷ ModuleName → Lua.Name → Lua.Name
-qualifyName modname = Fixture.psluaName . Name.join2 (fromModuleName modname)
+qualifyName modname = Name.join2 (fromModuleName modname)