Add builtin arithmetic operators

* also allow choosing evaluator
* ensures equivalence of evaluators up-to α-renaming
* checks server accepts answers from challenge

1 files changed, 10 insertions, 6 deletions

diff --git a/lambda-calcul/haskell/src/Minilang/REPL/Run.hs b/lambda-calcul/haskell/src/Minilang/REPL/Run.hs
index 8b9b844..26f3cad 100644
--- a/lambda-calcul/haskell/src/Minilang/REPL/Run.hs
+++ b/lambda-calcul/haskell/src/Minilang/REPL/Run.hs
@@ -8,7 +8,7 @@ module Minilang.REPL.Run where
 
 import Control.Monad.Catch
 import Data.Text hiding (replicate)
-import Minilang.Lambda (loadProgram, evalInEnv)
+import Minilang.Lambda (loadProgram, evalInEnvWith)
 import Minilang.Lambda.Eval (newEnv)
 import Minilang.Lambda.Infer (extendContext, infer, newContext)
 import qualified Minilang.Lambda.Infer as Infer
@@ -34,11 +34,11 @@ handleUserInput ::
   Text ->
   m ()
 handleUserInput txt = do
-  repl@REPLEnv {language, env, context} <- getEnv
+  repl@REPLEnv {language, evaluator, env, context} <- getEnv
   case parse txt of
     Left err -> output (Msg $ pack $ show err)
     Right (Def ident body) -> do
-      let v = evalInEnv env body
+      let v = evalInEnvWith evaluator env body
       case language of
         Typed ->
           case infer v of
@@ -54,7 +54,7 @@ handleUserInput txt = do
           setEnv $ repl {env = (ident, v) : env}
           output (Defined ident (TyVar "<?>"))
     Right expr -> do
-      let v = evalInEnv env expr
+      let v = evalInEnvWith evaluator env expr
           ast = resugar v
       case language of
         Typed ->
@@ -86,6 +86,10 @@ handleCommand (Set (SelectLanguage lang)) =
   getEnv >>= \e ->
     setEnv (e {language = lang})
       >> output (Msg $ "Language set to " <> pack (show lang))
+handleCommand (Set (SelectEvaluator ev)) =
+  getEnv >>= \e ->
+    setEnv (e {evaluator = ev})
+      >> output (Msg $ "Evaluator set to " <> pack (show ev))
 handleCommand Help =
   output (Msg helpText)
 
@@ -94,11 +98,11 @@ loadProgramInEnv ::
   Text ->
   m ()
 loadProgramInEnv prog = do
-  repl@REPLEnv {env, context, language} <- getEnv
+  repl@REPLEnv {env, context, language, evaluator} <- getEnv
   case parseProgram prog of
     Left err -> output (Msg $ pack $ show err)
     Right exprs -> do
-      case loadProgram language env context exprs of
+      case loadProgram evaluator language env context exprs of
         Left typeError -> output (Msg $ pack $ show typeError)
         Right (results, env', context') -> do
           setEnv (repl {env = env', context = context'})