better representation of evaluated terms in UI

1 files changed, 22 insertions, 2 deletions

diff --git a/lambda-calcul/haskell/public/repl.js b/lambda-calcul/haskell/public/repl.js
index 1d4453f..a99494a 100644
--- a/lambda-calcul/haskell/public/repl.js
+++ b/lambda-calcul/haskell/public/repl.js
@@ -49,10 +49,30 @@ function appendOutput(text) {
     }
 };
 
+function prettyTerm(term) {
+    if(term.tag === "Var") {
+        return term.contents;
+    } else if(term.tag === "Lam") {
+      return "(lam (" + term.contents[0] + ") " + prettyTerm(term.contents[1]) + ")";
+    } else if(term.tag === "App") {
+        return "(" + prettyTerm(term.contents[0]) + " " + prettyTerm(term.contents[1]) + ")";
+    }
+    return JSON.stringify(term);
+}
+
+function prettyType(type) {
+    if(type.tag === "TyVar") {
+        return type.contents;
+    } else if(type.tag === "TyArr") {
+        return "(" + prettyType(type.contents[0]) + " -> " + prettyType(type.contents[1]) + ")";
+    }
+    return JSON.stringify(type);
+}
+
 function formatResult(text) {
     const result = JSON.parse(text);
-    if (result.rendered) {
-        return result.rendered;
+    if (result.tag === "Evaluated") {
+      return prettyTerm(result.contents[0]) + ':' + prettyType(result.contents[1]);
     } else if (result.tag === "Msg" ) {
         return result.contents;
     }