Add rules for variable ref and related tests

corpus/quoted_argument.txt

@@ -64,3 +64,44 @@ with line break")
     )
   )
 )
+
+======================
+One variable reference
+======================
+
+message("${var}")
+
+---
+(source_file
+  (command_invocation
+    (identifier)
+    (arguments
+     (argument
+      (quoted_argument
+        (variable_ref (normal_var))
+      )
+     )
+    )
+  )
+)
+
+=======================
+Two Variable references
+=======================
+
+message("${var} ${var}")
+
+---
+(source_file
+  (command_invocation
+    (identifier)
+    (arguments
+     (argument
+      (quoted_argument
+        (variable_ref (normal_var))
+        (variable_ref (normal_var))
+      )
+     )
+    )
+  )
+)

corpus/unquoted_argument.txt

@@ -84,3 +84,23 @@ STATUS)
     )
   )
 )
+
+====================
+Variable referencing
+====================
+message(${var})
+---
+
+(source_file
+  (command_invocation
+    (identifier)
+    (arguments
+      (argument
+        (unquoted_argument
+          (variable_ref (normal_var))
+        )
+      )
+    )
+  )
+)
+

grammar.js

@@ -19,6 +19,20 @@ module.exports = grammar({
     _escape_encoded: $ => choice('\\t', '\\r', '\\n'),
     _escape_semicolon: $ => '\;',
 
+    variable_ref: $ => choice(
+      $.normal_var,
+      $.env_var,
+      $.cache_var,
+    ),
+    _literal_variable: $ => choice(
+      /[a-zA-Z0-9/_.+-]/,
+      $.escape_sequence,
+    ),
+    normal_var: $ => seq('${', repeat1($._literal_variable), '}'),
+    env_var: $ => seq('$ENV{', repeat1($._literal_variable), '}'),
+    cache_var: $ => seq('$CACHE{', repeat1($._literal_variable), '}'),
+
+
 
     argument: $ => choice(
       $.bracket_argument,
@@ -26,7 +40,6 @@ module.exports = grammar({
       $.unquoted_argument,
     ),
 
-
     bracket_argument: $ => seq(
       $._bracket_open,
       optional($._bracket_content),
@@ -38,6 +51,7 @@ module.exports = grammar({
 
     quoted_argument: $ => seq('"', repeat($._quoted_element), '"'),
     _quoted_element: $ => choice(
+      $.variable_ref,
       /[^\\"]/,
       $.escape_sequence,
       seq('\\', $.newline),
@@ -45,18 +59,19 @@ module.exports = grammar({
 
     unquoted_argument: $ => repeat1(
       choice(
+        $.variable_ref,
         /[^ ()#\"\\]/,
         $.escape_sequence,
       )
     ),
 
-
     arguments: $ => seq($.argument, repeat($._seperated_arguments)),
     _seperated_arguments: $ => prec.left(seq(
       repeat1($.seperation),
       optional($.argument)
     )),
 
+
     command_invocation: $ => seq(
       repeat($.space),
       $.identifier,

src/grammar.json

@@ -79,6 +79,96 @@
       "type": "STRING",
       "value": ";"
     },
+    "variable_ref": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "normal_var"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "env_var"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "cache_var"
+        }
+      ]
+    },
+    "_literal_variable": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "PATTERN",
+          "value": "[a-zA-Z0-9/_.+-]"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "escape_sequence"
+        }
+      ]
+    },
+    "normal_var": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "${"
+        },
+        {
+          "type": "REPEAT1",
+          "content": {
+            "type": "SYMBOL",
+            "name": "_literal_variable"
+          }
+        },
+        {
+          "type": "STRING",
+          "value": "}"
+        }
+      ]
+    },
+    "env_var": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "$ENV{"
+        },
+        {
+          "type": "REPEAT1",
+          "content": {
+            "type": "SYMBOL",
+            "name": "_literal_variable"
+          }
+        },
+        {
+          "type": "STRING",
+          "value": "}"
+        }
+      ]
+    },
+    "cache_var": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "$CACHE{"
+        },
+        {
+          "type": "REPEAT1",
+          "content": {
+            "type": "SYMBOL",
+            "name": "_literal_variable"
+          }
+        },
+        {
+          "type": "STRING",
+          "value": "}"
+        }
+      ]
+    },
     "argument": {
       "type": "CHOICE",
       "members": [
@@ -191,6 +281,10 @@
     "_quoted_element": {
       "type": "CHOICE",
       "members": [
+        {
+          "type": "SYMBOL",
+          "name": "variable_ref"
+        },
         {
           "type": "PATTERN",
           "value": "[^\\\\\"]"
@@ -219,6 +313,10 @@
       "content": {
         "type": "CHOICE",
         "members": [
+          {
+            "type": "SYMBOL",
+            "name": "variable_ref"
+          },
           {
             "type": "PATTERN",
             "value": "[^ ()#\\\"\\\\]"

src/node-types.json

@@ -46,6 +46,21 @@
     "named": true,
     "fields": {}
   },
+  {
+    "type": "cache_var",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": false,
+      "types": [
+        {
+          "type": "escape_sequence",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "command_invocation",
     "named": true,
@@ -73,6 +88,21 @@
       ]
     }
   },
+  {
+    "type": "env_var",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": false,
+      "types": [
+        {
+          "type": "escape_sequence",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "escape_sequence",
     "named": true,
@@ -93,6 +123,21 @@
       ]
     }
   },
+  {
+    "type": "normal_var",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": false,
+      "types": [
+        {
+          "type": "escape_sequence",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "quoted_argument",
     "named": true,
@@ -108,6 +153,10 @@
         {
           "type": "newline",
           "named": true
+        },
+        {
+          "type": "variable_ref",
+          "named": true
         }
       ]
     }
@@ -157,6 +206,33 @@
         {
           "type": "escape_sequence",
           "named": true
+        },
+        {
+          "type": "variable_ref",
+          "named": true
+        }
+      ]
+    }
+  },
+  {
+    "type": "variable_ref",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "cache_var",
+          "named": true
+        },
+        {
+          "type": "env_var",
+          "named": true
+        },
+        {
+          "type": "normal_var",
+          "named": true
         }
       ]
     }
@@ -165,6 +241,18 @@
     "type": "\"",
     "named": false
   },
+  {
+    "type": "$CACHE{",
+    "named": false
+  },
+  {
+    "type": "$ENV{",
+    "named": false
+  },
+  {
+    "type": "${",
+    "named": false
+  },
   {
     "type": "(",
     "named": false
@@ -212,5 +300,9 @@
   {
     "type": "space",
     "named": true
+  },
+  {
+    "type": "}",
+    "named": false
   }
 ]