Merge pull request #16 from nmattia/nm-tmp

Remove moduleIsMain

snack-lib/default.nix

@@ -97,44 +97,34 @@ let
   # Returns an attribute set where the keys are the module names and the values
   # are the '.o's
   flattenModuleObjects = ghcWith: mod0:
-    let
-      go = mod: attrs0:
-        let
-          objectName = x:
-            # TODO: can't justuse "moduleName.o" because some modules get
-            # renamed to "Main.o" :/ Also, hard coding the object file based on
-            # the module name feels icky
-            if x.moduleIsMain
-            then "Main.o"
-            else moduleToObject x.moduleName;
-          attrs1 = f attrs0 mod;
-          f = acc: elem:
-            if lib.attrsets.hasAttr elem.moduleName acc
-            then acc # breaks infinite recursion
-            else acc //
-              { "${elem.moduleName}" =
-                "${buildModule ghcWith elem}/${objectName elem}";
+    lib.fix (f: acc0: mods:
+      let
+        insertMod = acc: mod:
+          if lib.attrsets.hasAttr mod.moduleName acc
+          then acc
+          else
+            let acc' = acc //
+              { "${mod.moduleName}" =
+                "${buildModule ghcWith mod}/${moduleToObject mod.moduleName}";
               };
-        in
-          lib.lists.foldl f attrs1 mod.moduleImports;
-    in go mod0 {};
+            in f acc' mod.moduleImports;
+       in
+        lib.foldl insertMod acc0 mods
+      )
+      # XXX: the main modules need special handling regarding the object name
+      { "${mod0.moduleName}" = "${buildModule ghcWith mod0}/Main.o";}
+      mod0.moduleImports;
 
-  # TODO: this should be ghcWith
   linkModuleObjects = ghcWith: mod: # main module
     let
       objAttrs = flattenModuleObjects ghcWith mod;
       objList = lib.attrsets.mapAttrsToList (x: y: y) objAttrs;
-      # TODO: all recursive dependencies of "mod"
       deps = allTransitiveDeps [mod];
       ghc = ghcWith deps;
       ghcOptsArgs = lib.strings.escapeShellArgs mod.moduleGhcOpts;
       packageList = map (p: "-package ${p}") deps;
-    in stdenv.mkDerivation
-      { name = "linker";
-        src = null;
-        builder = writeScript "linker-builder"
+    in runCommand "linker" {}
         ''
-          source $stdenv/setup
           mkdir -p $out
           ${ghc}/bin/ghc \
             ${lib.strings.escapeShellArgs packageList} \
@@ -142,7 +132,6 @@ let
             ${ghcOptsArgs} \
             -o $out/out
         '';
-      };
 
   allModuleDirectories = modSpec:
     lib.lists.concatLists

snack-lib/module-spec.nix

@@ -10,14 +10,12 @@ rec {
     makeModuleSpec =
     modName:
     modImports:
-    isMain:
     modFiles:
     modDirs:
     modBase:
     modDeps:
     modGhcOpts:
     { moduleName = modName;
-      moduleIsMain = isMain;
 
       # local module imports, i.e. not part of an external dependency
       moduleImports = modImports;
@@ -34,6 +32,8 @@ rec {
 
   # Create a module spec by following the dependencies. This assumes that the
   # specified module is a "Main" module.
+  # TODO: pretty sure things will silently go wrong if several modules in the
+  # dependency tree share a common name
     makeModuleSpecRec =
     baseByModuleName:
     filesByModuleName:
@@ -41,19 +41,18 @@ rec {
     depsByModuleName:
     ghcOptsByModuleName:
     lib.fix
-      (f: isMain: modName:
+      (f: modName:
         makeModuleSpec
           modName
-          (map (f false)
+          (map f
             (lib.lists.filter (mn: baseByModuleName mn != null) (listModuleImports baseByModuleName modName))
           )
-          isMain
           (filesByModuleName modName)
           (dirsByModuleName modName)
           (baseByModuleName modName)
           (depsByModuleName modName)
           (ghcOptsByModuleName modName)
-      ) true;
+      );
 
   # Returns a list of all modules in the module spec graph
   flattenModuleSpec = modSpec:

snack-lib/modules.nix

@@ -14,6 +14,7 @@ rec {
     (lib.strings.replaceChars ["."] ["/"] mod) + ".hs";
 
   # Turns a module name into the filepath of its object file
+  # TODO: bad name, this is module _name_ to object
   moduleToObject = mod:
     (lib.strings.replaceChars ["."] ["/"] mod) + ".o";
 

tests/library/app/Bar.hs

@@ -0,0 +1,7 @@
+module Bar where
+
+import Conduit
+import FooBar
+
+main :: IO ()
+main = runConduit $ spitOut .| takeC 5 .| digest

tests/library/app/Foo.hs

@@ -1,5 +1,4 @@
-import Conduit
-import FooBar
+import qualified Bar
 
 main :: IO ()
-main = runConduit $ spitOut .| takeC 5 .| digest
+main = Bar.main