From c2d722d5abd121da48969e61d72e59f8101ea95a Mon Sep 17 00:00:00 2001
From: Mike Cifelli <michael.cifelli@gmail.com>
Date: Sun, 12 Mar 2017 14:18:37 -0400
Subject: [PATCH] Fix nested comma handling in a backquote

---
 src/function/builtin/BackquoteEvaluator.java |  7 +++++++
 test/function/builtin/EVALTester.java        | 14 ++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/function/builtin/BackquoteEvaluator.java b/src/function/builtin/BackquoteEvaluator.java
index c882423..e62738c 100644
--- a/src/function/builtin/BackquoteEvaluator.java
+++ b/src/function/builtin/BackquoteEvaluator.java
@@ -57,6 +57,8 @@ class BackquoteEvaluator {
             throw new AtSignNotInCommaException();
         else if (expression.isComma())
             resolveCommaExpression(expression);
+        else if (expression.isList())
+            resolveListExpression(expression);
         else
             addResolvedExpression(expression);
     }
@@ -122,6 +124,11 @@ class BackquoteEvaluator {
         leader = (Cons) leader.getRest();
     }
 
+    private void resolveListExpression(SExpression expression) {
+        BackquoteEvaluator evaluator = new BackquoteEvaluator(new BackquoteExpression(expression));
+        addResolvedExpression(evaluator.evaluate());
+    }
+
     private static class CommaEvaluationResult {
 
         private SExpression result;
diff --git a/test/function/builtin/EVALTester.java b/test/function/builtin/EVALTester.java
index 2b51bd4..ec6b9ff 100644
--- a/test/function/builtin/EVALTester.java
+++ b/test/function/builtin/EVALTester.java
@@ -148,4 +148,18 @@ public class EVALTester {
         assertIsErrorWithMessage(new UnmatchedAtSignException());
     }
 
+    @Test
+    public void evalQuoteInNestedList() {
+        String input = "(let ((g 27)) `((,g)))";
+
+        assertSExpressionsMatch(parseString("((27))"), evaluateString(input));
+    }
+
+    @Test
+    public void evalAtSignInNestedList() {
+        String input = "(let ((g '(1 2 3))) `((,@g)))";
+
+        assertSExpressionsMatch(parseString("((1 2 3))"), evaluateString(input));
+    }
+
 }