json: fix explosive integral grammar rules

Author: ochafik

examples/json_schema_to_grammar.py

@@ -12,8 +12,9 @@
 
 PRIMITIVE_RULES = {
     'boolean': '("true" | "false") space',
-    'integral-part': '[0-9] | [1-9] [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]?',
-    'decimal-part': '[0-9] [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]? [0-9]?',
+    'decimal-part': '[0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] [0-9]?)?)?)?)?)?)?)?)?)?',
+    'integral-part': '[0-9] | [1-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] ([0-9] [0-9]?)?)?)?)?)?)?)?)?)?',
+
     # 'number': '("-"? ([0-9] | [1-9] [0-9]*)) ("." [0-9]+)? ([eE] [-+]? [0-9]+)? space',
     # 'integer': '("-"? ([0-9] | [1-9] [0-9]*)) space',
     'number': '("-"? integral-part) ("." decimal-part)? ([eE] [-+]? integral-part)? space',