From d3b32398b59bf11d29bccdea0b7136192d208491 Mon Sep 17 00:00:00 2001
From: "Niels G. W. Serup" <ngws@metanohi.name>
Date: Fri, 27 Sep 2024 21:13:16 +0200
Subject: [PATCH] Implement DependencyRunner for MapComp

---
 byg/src/DependencyRunner.hs | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/byg/src/DependencyRunner.hs b/byg/src/DependencyRunner.hs
index 68e59aa..f014bcf 100644
--- a/byg/src/DependencyRunner.hs
+++ b/byg/src/DependencyRunner.hs
@@ -1,5 +1,7 @@
 module DependencyRunner
-  ( runDeps
+  ( DepRunM
+  , runDeps
+  , runDepRunM
   ) where
 
 import Types (Value(..), Valuable(..))
@@ -9,7 +11,7 @@ import Evaluation.FunctionIO
 
 import Data.Map (Map)
 import qualified Data.Map as M
-import Control.Monad.State (MonadState, MonadIO, StateT, runState, put, get, modify, liftIO)
+import Control.Monad.State (MonadState, MonadIO, StateT, evalStateT, get, modify, liftIO)
 
 newtype DepRunM a = DepRunM { unDepRunM :: StateT (Map Int Value) IO a }
   deriving (Functor, Applicative, Monad, MonadIO, MonadState (Map Int Value))
@@ -17,6 +19,9 @@ newtype DepRunM a = DepRunM { unDepRunM :: StateT (Map Int Value) IO a }
 runDeps :: [Dependency] -> DepRunM ()
 runDeps = mapM_ runDep
 
+runDepRunM :: DepRunM a -> IO a
+runDepRunM m = evalStateT (unDepRunM m) M.empty
+
 runDep :: Dependency -> DepRunM ()
 runDep (Dependency a action b) = do
   input <- getTokenValue a
@@ -91,4 +96,11 @@ runAction action input = case action of
       _ ->
         error "unexpected"
   MapComp subDeps innerInput innerOutput ->
-    undefined
+    case input of
+      List vs ->
+        (List <$>) $ flip mapM vs $ \v -> do
+          putTokenValue innerInput v
+          runDeps subDeps
+          getTokenValue innerOutput
+      _ ->
+        error "unexpected"