Add quoted command names, subshells

corpus/commands.txt

@@ -37,6 +37,17 @@ echo 'hi'
     (command_substitution (command (command_name)))))
   (command (command_name) (single_quoted_argument)))
 
+===============================
+Quoted command names
+===============================
+
+"$a/$b" c
+
+---
+
+(program
+  (command (quoted_argument (expansion (variable_name)) (expansion (variable_name))) (argument)))
+
 ===============================
 Commands with numeric arguments
 ===============================

corpus/control_flow.txt

@@ -84,3 +84,16 @@ esac
       (command (command_name) (argument)))
     (case_item (argument)
       (command (command_name) (argument)))))
+
+===============================
+Subshells
+===============================
+
+(
+  ./start-server --port=80
+) &
+
+---
+
+(program
+  (subshell (command (command_name) (argument))))

grammar.js

@@ -32,7 +32,8 @@ module.exports = grammar({
       $.if_statement,
       $.case_statement,
       $.pipeline,
-      $.list
+      $.list,
+      $.subshell
     ),
 
     while_statement: $ => seq(
@@ -83,7 +84,7 @@ module.exports = grammar({
       $.value,
       ')',
       repeat($._terminated_statement),
-      optional(';;')
+      ';;'
     ),
 
     bracket_command: $ => choice(
@@ -96,7 +97,12 @@ module.exports = grammar({
         $.environment_variable_assignment,
         $.file_redirect
       )),
-      rename($.leading_word, 'command_name'),
+      choice(
+        rename(choice($.leading_word), 'command_name'),
+        ':',
+        $.quoted_argument,
+        $.single_quoted_argument
+      ),
       optional(seq(
         /\s+/,
         repeat($.value)
@@ -119,6 +125,12 @@ module.exports = grammar({
       $.statement
     )),
 
+    subshell: $ => seq(
+      '(',
+      repeat($._terminated_statement),
+      ')'
+    ),
+
     environment_variable_assignment: $ => seq(
       rename($.leading_word, 'variable_name'),
       '=',
@@ -151,14 +163,17 @@ module.exports = grammar({
 
     expansion: $ => seq(
       '$',
-      rename($.word, 'variable_name')
+      choice(
+        rename($.word, 'variable_name'),
+        '$'
+      )
     ),
 
     operator_expansion: $ => seq(
       '${',
       rename($.leading_word, 'variable_name'),
       optional(seq(
-        choice(':', ':?', '='),
+        choice(':', ':?', '=', ':-'),
         $.value
       )),
       '}'
@@ -200,6 +215,6 @@ module.exports = grammar({
 
     comment: $ => /#.*/,
 
-    terminator: $ => choice(';', ';;', '\n'),
+    terminator: $ => choice(';', ';;', '\n', '&'),
   }
 });

src/grammar.json

@@ -55,6 +55,10 @@
         {
           "type": "SYMBOL",
           "name": "list"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "subshell"
         }
       ]
     },
@@ -245,16 +249,8 @@
           }
         },
         {
-          "type": "CHOICE",
-          "members": [
-            {
-              "type": "STRING",
-              "value": ";;"
-            },
-            {
-              "type": "BLANK"
-            }
-          ]
+          "type": "STRING",
+          "value": ";;"
         }
       ]
     },
@@ -323,12 +319,34 @@
           }
         },
         {
-          "type": "RENAME",
-          "content": {
-            "type": "SYMBOL",
-            "name": "leading_word"
-          },
-          "value": "command_name"
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "RENAME",
+              "content": {
+                "type": "CHOICE",
+                "members": [
+                  {
+                    "type": "SYMBOL",
+                    "name": "leading_word"
+                  }
+                ]
+              },
+              "value": "command_name"
+            },
+            {
+              "type": "STRING",
+              "value": ":"
+            },
+            {
+              "type": "SYMBOL",
+              "name": "quoted_argument"
+            },
+            {
+              "type": "SYMBOL",
+              "name": "single_quoted_argument"
+            }
+          ]
         },
         {
           "type": "CHOICE",
@@ -432,6 +450,26 @@
         ]
       }
     },
+    "subshell": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "("
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "SYMBOL",
+            "name": "_terminated_statement"
+          }
+        },
+        {
+          "type": "STRING",
+          "value": ")"
+        }
+      ]
+    },
     "environment_variable_assignment": {
       "type": "SEQ",
       "members": [
@@ -539,12 +577,21 @@
           "value": "$"
         },
         {
-          "type": "RENAME",
-          "content": {
-            "type": "SYMBOL",
-            "name": "word"
-          },
-          "value": "variable_name"
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "RENAME",
+              "content": {
+                "type": "SYMBOL",
+                "name": "word"
+              },
+              "value": "variable_name"
+            },
+            {
+              "type": "STRING",
+              "value": "$"
+            }
+          ]
         }
       ]
     },
@@ -583,6 +630,10 @@
                     {
                       "type": "STRING",
                       "value": "="
+                    },
+                    {
+                      "type": "STRING",
+                      "value": ":-"
                     }
                   ]
                 },
@@ -764,6 +815,10 @@
         {
           "type": "STRING",
           "value": "\n"
+        },
+        {
+          "type": "STRING",
+          "value": "&"
         }
       ]
     }