Add support for exporting environment variables (#4)

* Add support for exporting environment variables

* Support multiple exports in one command

Also improves the structure of the AST so the variable name and the
assigned expression aren't free-floating

* Allow for multiple declarations in local declarations as well

Simplify the generated nodes.

* Commit generated code

* Consolidate declarations into a single declaration_command

This also adds support for declare, typeset, and readonly

* Rename environment_variable_assignment to variable_assignment

corpus/commands.txt

@@ -72,11 +72,11 @@ VAR1=a VAR2="ok" git diff --word-diff=color
 
 (program
   (command
-    (environment_variable_assignment (variable_name) (word))
+    (variable_assignment (variable_name) (word))
     (command_name (word)))
   (command
-    (environment_variable_assignment (variable_name) (word))
-    (environment_variable_assignment (variable_name) (string))
+    (variable_assignment (variable_name) (word))
+    (variable_assignment (variable_name) (string))
     (command_name (word))
     (word)
     (word)))
@@ -91,8 +91,8 @@ VAR2= echo
 ---
 
 (program
-  (environment_variable_assignment (variable_name))
-  (command (environment_variable_assignment (variable_name)) (command_name (word))))
+  (variable_assignment (variable_name))
+  (command (variable_assignment (variable_name)) (command_name (word))))
 
 ===================================
 Pipelines

corpus/expressions.txt

@@ -144,22 +144,62 @@ find "`dirname $file`" -name "$base"'*'
       (raw_string))))
 
 =========================================
-Local Variable Declaration
+Variable declaration: declare & typeset
 =========================================
 
-function a {
-  local a=42
-  local b
-}
+declare var1
+typeset -i -r var2=42 var3=10
 
 ---
 
 (program
-  (function_definition
-    (word)
-    (compound_statement
-      (local_variable_declaration (simple_variable_name) (word))
-      (local_variable_declaration (simple_variable_name)))))
+  (declaration_command (simple_variable_name))
+  (declaration_command (argument) (argument)
+    (variable_assignment (variable_name) (word))
+    (variable_assignment (variable_name) (word))))
+
+=========================================
+Variable declaration: readonly
+=========================================
+
+readonly var1
+readonly var2=42
+
+---
+
+(program
+  (declaration_command (simple_variable_name))
+  (declaration_command (variable_assignment (variable_name) (word))))
+
+=========================================
+Variable declaration: local
+=========================================
+
+local a=42 b
+local -r c
+
+---
+
+(program
+  (declaration_command
+    (variable_assignment (variable_name) (word))
+    (simple_variable_name))
+  (declaration_command (argument) (simple_variable_name)))
+
+=========================================
+Variable declaration: export
+=========================================
+
+export PATH
+export FOOBAR PATH="$PATH:/usr/foobar/bin"
+
+---
+
+(program
+  (declaration_command (simple_variable_name))
+  (declaration_command
+    (simple_variable_name)
+    (variable_assignment (variable_name) (string (simple_expansion (variable_name))))))
 
 =========================================
 Arrays and array expansions
@@ -177,14 +217,14 @@ a+=(foo "bar" $(baz))
 ---
 
 (program
-  (environment_variable_assignment (variable_name) (array))
-  (environment_variable_assignment (variable_name) (array (word) (word) (word)))
+  (variable_assignment (variable_name) (array))
+  (variable_assignment (variable_name) (array (word) (word) (word)))
   (command (command_name (word)) (expansion (variable_name)))
   (command (command_name (word)) (expansion (variable_name)))
-  (environment_variable_assignment
+  (variable_assignment
     (subscript (variable_name) (simple_expansion (variable_name)))
     (word))
-  (environment_variable_assignment
+  (variable_assignment
     (variable_name)
     (array
       (word)

corpus/programs.txt

@@ -32,10 +32,10 @@ f=g   \
     (word)
     (word))
   (command
-    (environment_variable_assignment
+    (variable_assignment
       (variable_name)
       (word))
-    (environment_variable_assignment
+    (variable_assignment
       (variable_name)
       (word))
     (command_name (word))

grammar.js

@@ -47,11 +47,9 @@ module.exports = grammar({
     // Statements
 
     _statement: $ => choice(
-      $.environment_variable_assignment,
-      // Local variable are only allowed inside the body of a function, but to
-      // keep the grammar simple we'll ignore that requirements.
-      $.local_variable_declaration,
+      $.variable_assignment,
       $.command,
+      $.declaration_command,
       $.bracket_command,
       $.for_statement,
       $.while_statement,
@@ -167,7 +165,7 @@ module.exports = grammar({
 
     command: $ => prec.left(seq(
       repeat(choice(
-        $.environment_variable_assignment,
+        $.variable_assignment,
         $.file_redirect
       )),
       $.command_name,
@@ -180,7 +178,7 @@ module.exports = grammar({
 
     command_name: $ => $._expression,
 
-    environment_variable_assignment: $ => seq(
+    variable_assignment: $ => seq(
       choice(
         $.variable_name,
         $.subscript
@@ -188,10 +186,13 @@ module.exports = grammar({
       $._assignment
     ),
 
-    local_variable_declaration: $ => seq(
-      'local',
+    declaration_command: $ => seq(
+      choice('declare', 'typeset', 'export', 'readonly', 'local'),
+      repeat(alias(seq('-', $.word), 'argument')),
+      repeat(choice(
         $.simple_variable_name,
-      optional($._assignment)
+        $.variable_assignment
+      ))
     ),
 
     _assignment: $ => seq(

src/grammar.json

@@ -26,16 +26,16 @@
       "members": [
         {
           "type": "SYMBOL",
-          "name": "environment_variable_assignment"
-        },
-        {
-          "type": "SYMBOL",
-          "name": "local_variable_declaration"
+          "name": "variable_assignment"
         },
         {
           "type": "SYMBOL",
           "name": "command"
         },
+        {
+          "type": "SYMBOL",
+          "name": "declaration_command"
+        },
         {
           "type": "SYMBOL",
           "name": "bracket_command"
@@ -546,7 +546,7 @@
               "members": [
                 {
                   "type": "SYMBOL",
-                  "name": "environment_variable_assignment"
+                  "name": "variable_assignment"
                 },
                 {
                   "type": "SYMBOL",
@@ -589,7 +589,7 @@
       "type": "SYMBOL",
       "name": "_expression"
     },
-    "environment_variable_assignment": {
+    "variable_assignment": {
       "type": "SEQ",
       "members": [
         {
@@ -611,29 +611,71 @@
         }
       ]
     },
-    "local_variable_declaration": {
+    "declaration_command": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "STRING",
+              "value": "declare"
+            },
+            {
+              "type": "STRING",
+              "value": "typeset"
+            },
+            {
+              "type": "STRING",
+              "value": "export"
+            },
+            {
+              "type": "STRING",
+              "value": "readonly"
+            },
+            {
+              "type": "STRING",
+              "value": "local"
+            }
+          ]
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "ALIAS",
+            "content": {
               "type": "SEQ",
               "members": [
                 {
                   "type": "STRING",
-          "value": "local"
+                  "value": "-"
                 },
+                {
+                  "type": "SYMBOL",
+                  "name": "word"
+                }
+              ]
+            },
+            "named": false,
+            "value": "argument"
+          }
+        },
+        {
+          "type": "REPEAT",
+          "content": {
+            "type": "CHOICE",
+            "members": [
               {
                 "type": "SYMBOL",
                 "name": "simple_variable_name"
               },
-        {
-          "type": "CHOICE",
-          "members": [
               {
                 "type": "SYMBOL",
-              "name": "_assignment"
-            },
-            {
-              "type": "BLANK"
+                "name": "variable_assignment"
               }
             ]
           }
+        }
       ]
     },
     "_assignment": {