add True, False, None

src/grammar.json

@@ -122,6 +122,14 @@
         {
           "type": "SYMBOL",
           "name": "translated_string"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "boolean"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "none"
         }
       ]
     },
@@ -150,6 +158,23 @@
         }
       ]
     },
+    "boolean": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "True"
+        },
+        {
+          "type": "STRING",
+          "value": "False"
+        }
+      ]
+    },
+    "none": {
+      "type": "STRING",
+      "value": "None"
+    },
     "attribute": {
       "type": "PATTERN",
       "value": "[a-zA-Z0-9][a-zA-Z0-9_]*(?:\\.[a-zA-Z0-9][a-zA-Z0-9_]*)*"

src/node-types.json

@@ -396,6 +396,11 @@
       ]
     }
   },
+  {
+    "type": "boolean",
+    "named": true,
+    "fields": {}
+  },
   {
     "type": "cache_clause",
     "named": true,
@@ -1699,6 +1704,14 @@
       "multiple": false,
       "required": true,
       "types": [
+        {
+          "type": "boolean",
+          "named": true
+        },
+        {
+          "type": "none",
+          "named": true
+        },
         {
           "type": "number",
           "named": true
@@ -2650,6 +2663,14 @@
     "type": ">=",
     "named": false
   },
+  {
+    "type": "False",
+    "named": false
+  },
+  {
+    "type": "True",
+    "named": false
+  },
   {
     "type": "_(",
     "named": false
@@ -3074,6 +3095,10 @@
     "type": "media",
     "named": false
   },
+  {
+    "type": "none",
+    "named": true
+  },
   {
     "type": "noop",
     "named": false