Add 2 things:

- Escape sequence
- Seperation before arguments

corpus/unquoted_argument.txt

@@ -33,3 +33,29 @@ message(STATUS Hello)
     )
   )
 )
+
+===========================================
+Command invocations with leading seperation
+===========================================
+
+message( STATUS)
+message(
+STATUS)
+---
+
+(source_file
+  (command_invocation
+    (identifier)
+    (seperation (space))
+    (arguments
+      (argument (unquoted_argument))
+    )
+  )
+  (command_invocation
+    (identifier)
+    (seperation (line_ending (newline)))
+    (arguments
+      (argument (unquoted_argument))
+    )
+  )
+)

grammar.js

@@ -10,12 +10,27 @@ module.exports = grammar({
     newline: $ => /\n/,
     identifier: $ => /[A-Za-z_][A-Za-z0-9_]*/,
 
+    escape_sequence: $ => choice(
+      $._escape_identity,
+      $._escape_encoded,
+      $._escape_semicolon,
+    ),
+    _escape_identity: $ => /\\[^A-Za-z0-9;]/,
+    _escape_encoded: $ => choice('\\t', '\\r', '\\n'),
+    _escape_semicolon: $ => '\;',
+
+
     argument: $ => choice(
       $.unquoted_argument,
       $.bracket_argument,
     ),
 
-    unquoted_argument: $ => repeat1(/[^ ()#\"\\]/),
+    unquoted_argument: $ => repeat1(
+      choice(
+        /[^ ()#\"\\]/,
+        $.escape_sequence,
+      )
+    ),
 
     bracket_argument: $ => seq(
       $._bracket_open,
@@ -36,7 +51,7 @@ module.exports = grammar({
     command_invocation: $ => seq(
       repeat($.space),
       $.identifier,
-      repeat($.space),
+      repeat($.seperation),
       '(',
       repeat($.seperation),
       optional($.arguments),

src/grammar.json

@@ -37,6 +37,48 @@
       "type": "PATTERN",
       "value": "[A-Za-z_][A-Za-z0-9_]*"
     },
+    "escape_sequence": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "_escape_identity"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_escape_encoded"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_escape_semicolon"
+        }
+      ]
+    },
+    "_escape_identity": {
+      "type": "PATTERN",
+      "value": "\\\\[^A-Za-z0-9;]"
+    },
+    "_escape_encoded": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "\\t"
+        },
+        {
+          "type": "STRING",
+          "value": "\\r"
+        },
+        {
+          "type": "STRING",
+          "value": "\\n"
+        }
+      ]
+    },
+    "_escape_semicolon": {
+      "type": "STRING",
+      "value": ";"
+    },
     "argument": {
       "type": "CHOICE",
       "members": [
@@ -53,8 +95,17 @@
     "unquoted_argument": {
       "type": "REPEAT1",
       "content": {
-        "type": "PATTERN",
-        "value": "[^ ()#\\\"\\\\]"
+        "type": "CHOICE",
+        "members": [
+          {
+            "type": "PATTERN",
+            "value": "[^ ()#\\\"\\\\]"
+          },
+          {
+            "type": "SYMBOL",
+            "name": "escape_sequence"
+          }
+        ]
       }
     },
     "bracket_argument": {
@@ -191,7 +242,7 @@
           "type": "REPEAT",
           "content": {
             "type": "SYMBOL",
-            "name": "space"
+            "name": "seperation"
           }
         },
         {

src/node-types.json

@@ -69,6 +69,11 @@
       ]
     }
   },
+  {
+    "type": "escape_sequence",
+    "named": true,
+    "fields": {}
+  },
   {
     "type": "line_ending",
     "named": true,
@@ -121,7 +126,17 @@
   {
     "type": "unquoted_argument",
     "named": true,
-    "fields": {}
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": false,
+      "types": [
+        {
+          "type": "escape_sequence",
+          "named": true
+        }
+      ]
+    }
   },
   {
     "type": "(",
@@ -139,6 +154,18 @@
     "type": "[",
     "named": false
   },
+  {
+    "type": "\\n",
+    "named": false
+  },
+  {
+    "type": "\\r",
+    "named": false
+  },
+  {
+    "type": "\\t",
+    "named": false
+  },
   {
     "type": "]",
     "named": false