update regexes to match django

grammar.js

@@ -73,9 +73,12 @@ const django = grammar({
       seq($.filter, repeat(seq(token.immediate("|"), $.filter))),
     value: ($) => choice($.literal, $.variable_attribute),
     literal: ($) => seq(choice($.number, $.string), $._after_literal),
-    number: ($) => /[-+]?(?:[0-9]+(?:\.[0-9]*)?|\.[0-9]+)(?:[eE][0-9]+)?/,
+    // digits, with single underscores allowed between them, as Python's
+    // int() and float() accept ("1_000") and Django's Variable relies on
+    number: ($) =>
+      /[-+]?(?:[0-9](?:_?[0-9])*(?:\.(?:[0-9](?:_?[0-9])*)?)?|\.[0-9](?:_?[0-9])*)(?:[eE][0-9](?:_?[0-9])*)?/,
     string: ($) => /"(?:[^"\\]|\\[^\n])*"|'(?:[^'\\]|\\[^\n])*'/,
-    attribute: ($) => /[a-zA-Z0-9_]+(?:\.[a-zA-Z0-9_]+)*/,
+    attribute: ($) => /[a-zA-Z0-9][a-zA-Z0-9_]*(?:\.[a-zA-Z0-9][a-zA-Z0-9_]*)*/,
     variable_attribute: ($) =>
       seq($.identifier, optional(seq(token.immediate("."), $.attribute))),
     identifier: ($) => /[a-zA-Z][a-zA-Z0-9_]*/,

src/grammar.json

@@ -138,7 +138,7 @@
     },
     "number": {
       "type": "PATTERN",
-      "value": "[-+]?(?:[0-9]+(?:\\.[0-9]*)?|\\.[0-9]+)(?:[eE][0-9]+)?"
+      "value": "[-+]?(?:[0-9](?:_?[0-9])*(?:\\.(?:[0-9](?:_?[0-9])*)?)?|\\.[0-9](?:_?[0-9])*)(?:[eE][0-9](?:_?[0-9])*)?"
     },
     "string": {
       "type": "PATTERN",
@@ -146,7 +146,7 @@
     },
     "attribute": {
       "type": "PATTERN",
-      "value": "[a-zA-Z0-9_]+(?:\\.[a-zA-Z0-9_]+)*"
+      "value": "[a-zA-Z0-9][a-zA-Z0-9_]*(?:\\.[a-zA-Z0-9][a-zA-Z0-9_]*)*"
     },
     "variable_attribute": {
       "type": "SEQ",

test/corpus/template_variable.txt

@@ -246,3 +246,31 @@ Template Variable Signed Number
           (number)))))
   (content))
 
+==================
+Template Variable Underscore Separated Number
+==================
+
+{{ 1_000 }}
+
+---
+
+(template
+  (content)
+  (template_variable
+    (filtered_value
+      (value
+        (literal
+          (number)))))
+  (content))
+
+==================
+Template Variable Attribute Beginning With Underscore
+:error
+==================
+
+{{ user._private }}
+
+---
+
+(ERROR)
+