4 files changed, 9 insertions, 5 deletions
diff --git a/ast/CC/Context.hs b/ast/CC/Context.hs
index b86685d..68378d7 100644
--- a/ast/CC/Context.hs
+++ b/ast/CC/Context.hs
@@ -1,5 +1,7 @@
 module CC.Context where
 
+import Data.Map.Strict (Map)
+
 import CC.AST.Typed
 
 
@@ -7,4 +9,4 @@ import CC.AST.Typed
 data Context = Context FilePath Builtins
 
 -- | Information about builtins supported by the enabled backend
-data Builtins = Builtins [(Name, Type)]
+data Builtins = Builtins (Map Name Type)
diff --git a/backend/CC/Backend/Dumb.hs b/backend/CC/Backend/Dumb.hs
index 7982a06..3210dab 100644
--- a/backend/CC/Backend/Dumb.hs
+++ b/backend/CC/Backend/Dumb.hs
@@ -1,11 +1,13 @@
 module CC.Backend.Dumb(builtins) where
 
+import qualified Data.Map.Strict as Map
+
 import CC.AST.Typed
 import CC.Context
 
 
 builtins :: Builtins
-builtins = Builtins
+builtins = Builtins . Map.fromList $
     [ ("print", TFun TInt (TTup []))
     , ("fst", TFun (TTup [TyVar 1, TyVar 2]) (TyVar 1))
     , ("snd", TFun (TTup [TyVar 1, TyVar 2]) (TyVar 2))
diff --git a/compcomp.cabal b/compcomp.cabal
index 0b65ac1..9e941aa 100644
--- a/compcomp.cabal
+++ b/compcomp.cabal
@@ -32,13 +32,13 @@ library               cc-typecheck
 library               cc-backend-dumb
     import:           deps
     hs-source-dirs:   backend
-    build-depends:    cc-ast, cc-utils
+    build-depends:    containers, cc-ast, cc-utils
     exposed-modules:  CC.Backend.Dumb
 
 library               cc-ast
     import:           deps
     hs-source-dirs:   ast
-    build-depends:    cc-utils
+    build-depends:    containers, cc-utils
     exposed-modules:  CC.AST.Source, CC.AST.Typed, CC.Context
 
 library               cc-utils
diff --git a/typecheck/CC/Typecheck.hs b/typecheck/CC/Typecheck.hs
index 8803a62..f61103e 100644
--- a/typecheck/CC/Typecheck.hs
+++ b/typecheck/CC/Typecheck.hs
@@ -193,7 +193,7 @@ inferList env (expr : exprs) = do
 
 runPass :: Context -> S.Program -> Either TCError T.Program
 runPass (Context _ (Builtins builtins)) prog =
-    let env = Env (Map.fromList [(name, generalise emptyEnv ty) | (name, ty) <- builtins])
+    let env = Env (Map.map (generalise emptyEnv) builtins)
     in runTM (typeCheck env prog)
 
 typeCheck :: Env -> S.Program -> TM T.Program