From 6f95f38373e4c8d0bcf6b3de106d1422e56d2845 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Wed, 11 Mar 2026 16:19:40 -0500
Subject: [PATCH] xo-interpreter2: + nil + cons

---
 include/xo/tokenizer2/Token.hpp     | 2 ++
 include/xo/tokenizer2/tokentype.hpp | 3 +++
 src/tokenizer2/Tokenizer.cpp        | 2 ++
 src/tokenizer2/tokentype.cpp        | 1 +
 4 files changed, 8 insertions(+)

diff --git a/include/xo/tokenizer2/Token.hpp b/include/xo/tokenizer2/Token.hpp
index 7537a2b0..0968a9e9 100644
--- a/include/xo/tokenizer2/Token.hpp
+++ b/include/xo/tokenizer2/Token.hpp
@@ -134,6 +134,8 @@ namespace xo {
             /** token for @c "==" **/
             static Token cmpeq_token() { return Token(tokentype::tk_cmpeq); }
 
+            /** token representing keyword @c nil **/
+            static Token nil_token() { return Token(tokentype::tk_nil); }
             /** token representing keyword @c type **/
             static Token type() { return Token(tokentype::tk_type); }
             /** token representing keyword @c def **/
diff --git a/include/xo/tokenizer2/tokentype.hpp b/include/xo/tokenizer2/tokentype.hpp
index d0290b05..5f7e1937 100644
--- a/include/xo/tokenizer2/tokentype.hpp
+++ b/include/xo/tokenizer2/tokentype.hpp
@@ -140,6 +140,9 @@ namespace xo {
             /** operator @c '!=' **/
             tk_cmpne,
 
+            /** keyword @c 'nil' **/
+            tk_nil,
+
             /** keyword @c 'type' **/
             tk_type,
 
diff --git a/src/tokenizer2/Tokenizer.cpp b/src/tokenizer2/Tokenizer.cpp
index f6ac7c2f..2a6f8ed9 100644
--- a/src/tokenizer2/Tokenizer.cpp
+++ b/src/tokenizer2/Tokenizer.cpp
@@ -587,6 +587,8 @@ namespace xo {
                 if ((tk_text == "true") || (tk_text == "false")) {
                     tk_type = tokentype::tk_bool;
                     keep_text = true;
+                } else if (tk_text == "nil") {
+                    tk_type = tokentype::tk_nil;
                 } else if (tk_text == "type") {
                     tk_type = tokentype::tk_type;
                 } else if (tk_text == "def") {
diff --git a/src/tokenizer2/tokentype.cpp b/src/tokenizer2/tokentype.cpp
index 7df59eec..b8a013da 100644
--- a/src/tokenizer2/tokentype.cpp
+++ b/src/tokenizer2/tokentype.cpp
@@ -49,6 +49,7 @@ namespace xo {
                 CASE(tk_cmpeq);
                 CASE(tk_cmpne);
 
+                CASE(tk_nil);
                 CASE(tk_type);
                 CASE(tk_def);
                 CASE(tk_deftype);