Support running the dependency runner from the command line

Will fail currently

byg/src/DependencyRunner.hs

@@ -1,7 +1,7 @@
 module DependencyRunner
   ( DepRunM
   , runDeps
-  , runDepRunM
+  , runDepRunMIO
   ) where
 
 import Types (Value(..), Valuable(..))
@@ -19,8 +19,8 @@ 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
+runDepRunMIO :: DepRunM a -> IO a
+runDepRunMIO m = evalStateT (unDepRunM m) M.empty
 
 runDep :: Dependency -> DepRunM ()
 runDep (Dependency a action b) = do

byg/src/Main.hs

@@ -4,7 +4,9 @@ module Main where
 import Types.Dependency (Dependency, formatDependencyTrees)
 import DependencyGenerator (evalDepGenM)
 import SiteGenerator (generateSite)
+import DependencyRunner (runDeps, runDepRunMIO)
 
+import System.Environment (getArgs)
 import qualified Data.Text.IO as T
 import Language.Haskell.TH.Syntax (lift)
 
@@ -12,4 +14,12 @@ dependencies :: [Dependency]
 dependencies = $(lift (evalDepGenM generateSite))
 
 main :: IO ()
-main = T.putStr $ formatDependencyTrees dependencies
+main = do
+  args <- getArgs
+  case args of
+    ["run"] ->
+      runDepRunMIO $ runDeps dependencies
+    ["tree"] ->
+      T.putStr $ formatDependencyTrees dependencies
+    _ ->
+      error "unexpected arguments"