Add file redirects

corpus/commands.txt

@@ -77,3 +77,26 @@ a | b && c; d e f | e g
     (pipeline
       (simple_command (command_name) (argument) (argument))
       (simple_command (command_name) (argument))))))
+
+===============================
+File redirects
+===============================
+
+whoami > /dev/null
+cat a b 2> /dev/null
+2>&1 whoami
+
+---
+
+(program
+  (command (simple_command
+    (command_name)
+    (file_redirect (file_name))))
+  (command (simple_command
+    (command_name)
+    (argument)
+    (argument)
+    (file_redirect (file_descriptor) (file_name))))
+  (command (simple_command
+    (file_redirect (file_descriptor) (file_descriptor))
+    (command_name))))

grammar.js

@@ -16,12 +16,18 @@ module.exports = grammar({
     ),
 
     simple_command: $ => seq(
-      repeat($.environment_variable_assignment),
+      repeat(choice(
+        $.environment_variable_assignment,
+        $.file_redirect
+      )),
       rename($.leading_word, 'command_name'),
       optional(seq(
         /\s+/,
         repeat(rename($.word, 'argument'))
-      ))
+      )),
+      repeat(
+        $.file_redirect
+      )
     ),
 
     pipeline: $ => prec.left(seq(
@@ -49,9 +55,20 @@ module.exports = grammar({
       rename($.word, 'argument')
     ),
 
+    file_redirect: $ => seq(
+      optional($.file_descriptor),
+      choice('<', '>', '<&', '>&'),
+      choice(
+        $.file_descriptor,
+        rename($.word, 'file_name')
+      )
+    ),
+
+    file_descriptor: $ => token(prec(1, /\d+/)),
+
     leading_word: $ => /[^\s=|;]+/,
 
-    word: $ => /[^\s]+/,
+    word: $ => /[^\s<>&]+/,
 
     control_operator: $ => choice(
       '\n',

src/grammar.json

@@ -40,8 +40,17 @@
         {
           "type": "REPEAT",
           "content": {
+            "type": "CHOICE",
+            "members": [
+              {
                 "type": "SYMBOL",
                 "name": "environment_variable_assignment"
+              },
+              {
+                "type": "SYMBOL",
+                "name": "file_redirect"
+              }
+            ]
           }
         },
         {
@@ -79,6 +88,13 @@
               "type": "BLANK"
             }
           ]
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "SYMBOL",
+            "name": "file_redirect"
+          }
         }
       ]
     },
@@ -189,13 +205,79 @@
         }
       ]
     },
+    "file_redirect": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "SYMBOL",
+              "name": "file_descriptor"
+            },
+            {
+              "type": "BLANK"
+            }
+          ]
+        },
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "STRING",
+              "value": "<"
+            },
+            {
+              "type": "STRING",
+              "value": ">"
+            },
+            {
+              "type": "STRING",
+              "value": "<&"
+            },
+            {
+              "type": "STRING",
+              "value": ">&"
+            }
+          ]
+        },
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "SYMBOL",
+              "name": "file_descriptor"
+            },
+            {
+              "type": "RENAME",
+              "content": {
+                "type": "SYMBOL",
+                "name": "word"
+              },
+              "value": "file_name"
+            }
+          ]
+        }
+      ]
+    },
+    "file_descriptor": {
+      "type": "TOKEN",
+      "content": {
+        "type": "PREC",
+        "value": 1,
+        "content": {
+          "type": "PATTERN",
+          "value": "\\d+"
+        }
+      }
+    },
     "leading_word": {
       "type": "PATTERN",
       "value": "[^\\s=|;]+"
     },
     "word": {
       "type": "PATTERN",
-      "value": "[^\\s]+"
+      "value": "[^\\s<>&]+"
     },
     "control_operator": {
       "type": "CHOICE",