add basic keywords

grammar.js

@@ -1,13 +1,33 @@
 module.exports = grammar({
   name: "d2",
 
+  word: ($) => $._word,
+
   rules: {
     // TODO: add the actual grammar rules
     source_file: ($) => repeat($._definition),
 
-    _definition: ($) => choice($.connection, $.shape),
+    _definition: ($) => choice($.attribute, $.connection, $.shape),
 
-    _end: ($) => choice(";", "\n"),
+    _end: ($) => choice(";", "\n", "\0"),
+
+    attribute: ($) =>
+      choice(
+        seq(
+          $.identifier,
+          repeat1(seq($.dot, $.keyword)),
+          ":",
+          alias($.label, $.attribute_value),
+          $._end
+        ),
+        seq(
+          $.keyword,
+          repeat(seq($.dot, $.keyword)),
+          ":",
+          alias($.label, $.attribute_value),
+          $._end
+        )
+      ),
 
     connection: ($) =>
       seq(
@@ -33,6 +53,8 @@ module.exports = grammar({
 
     identifier: ($) => $._identifier,
 
+    keyword: ($) => choice("direction"),
+
     _identifier: ($) =>
       prec.right(
         seq(

src/grammar.json

@@ -1,5 +1,6 @@
 {
   "name": "d2",
+  "word": "_word",
   "rules": {
     "source_file": {
       "type": "REPEAT",
@@ -11,6 +12,10 @@
     "_definition": {
       "type": "CHOICE",
       "members": [
+        {
+          "type": "SYMBOL",
+          "name": "attribute"
+        },
         {
           "type": "SYMBOL",
           "name": "connection"
@@ -31,6 +36,99 @@
         {
           "type": "STRING",
           "value": "\n"
+        },
+        {
+          "type": "STRING",
+          "value": "\u0000"
+        }
+      ]
+    },
+    "attribute": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "SYMBOL",
+              "name": "identifier"
+            },
+            {
+              "type": "REPEAT1",
+              "content": {
+                "type": "SEQ",
+                "members": [
+                  {
+                    "type": "SYMBOL",
+                    "name": "dot"
+                  },
+                  {
+                    "type": "SYMBOL",
+                    "name": "keyword"
+                  }
+                ]
+              }
+            },
+            {
+              "type": "STRING",
+              "value": ":"
+            },
+            {
+              "type": "ALIAS",
+              "content": {
+                "type": "SYMBOL",
+                "name": "label"
+              },
+              "named": true,
+              "value": "attribute_value"
+            },
+            {
+              "type": "SYMBOL",
+              "name": "_end"
+            }
+          ]
+        },
+        {
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "SYMBOL",
+              "name": "keyword"
+            },
+            {
+              "type": "REPEAT",
+              "content": {
+                "type": "SEQ",
+                "members": [
+                  {
+                    "type": "SYMBOL",
+                    "name": "dot"
+                  },
+                  {
+                    "type": "SYMBOL",
+                    "name": "keyword"
+                  }
+                ]
+              }
+            },
+            {
+              "type": "STRING",
+              "value": ":"
+            },
+            {
+              "type": "ALIAS",
+              "content": {
+                "type": "SYMBOL",
+                "name": "label"
+              },
+              "named": true,
+              "value": "attribute_value"
+            },
+            {
+              "type": "SYMBOL",
+              "name": "_end"
+            }
+          ]
         }
       ]
     },
@@ -170,6 +268,15 @@
       "type": "SYMBOL",
       "name": "_identifier"
     },
+    "keyword": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "direction"
+        }
+      ]
+    },
     "_identifier": {
       "type": "PREC_RIGHT",
       "value": 0,

src/node-types.json

@@ -4,6 +4,48 @@
     "named": true,
     "fields": {}
   },
+  {
+    "type": "attribute",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": true,
+      "types": [
+        {
+          "type": "attribute_value",
+          "named": true
+        },
+        {
+          "type": "dot",
+          "named": true
+        },
+        {
+          "type": "identifier",
+          "named": true
+        },
+        {
+          "type": "keyword",
+          "named": true
+        }
+      ]
+    }
+  },
+  {
+    "type": "attribute_value",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": false,
+      "types": [
+        {
+          "type": "string",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "connection",
     "named": true,
@@ -32,6 +74,11 @@
     "named": true,
     "fields": {}
   },
+  {
+    "type": "keyword",
+    "named": true,
+    "fields": {}
+  },
   {
     "type": "label",
     "named": true,
@@ -78,6 +125,10 @@
       "multiple": true,
       "required": false,
       "types": [
+        {
+          "type": "attribute",
+          "named": true
+        },
         {
           "type": "connection",
           "named": true
@@ -94,6 +145,10 @@
     "named": true,
     "fields": {}
   },
+  {
+    "type": "\u0000",
+    "named": false
+  },
   {
     "type": "\n",
     "named": false
@@ -138,6 +193,10 @@
     "type": "`",
     "named": false
   },
+  {
+    "type": "direction",
+    "named": false
+  },
   {
     "type": "dot",
     "named": true

test/corpus/attributes.txt

@@ -0,0 +1,12 @@
+==================
+Keywords
+==================
+
+direction: value
+
+---
+
+(source_file
+  (attribute (keyword) (attribute_value))
+)
+