ebnf.py: added a fast-path ebnf-Parser if less flexibility regarding the variants

of EBNF-syntax is acceptable.

DHParser/ebnf.py

@@ -674,13 +674,13 @@ def get_ebnf_grammar() -> EBNFGrammar:
                 raise AttributeError
     except AttributeError:
         if mode in ('fixed', 'configurable'):
-            grammar = FixedEBNFGrammar()
+            grammar = FixedEBNFGrammar(static_analysis=False)
             if mode == "fixed":
                 # configure grammar once
                 update_scanner(grammar, get_config_value('delimiter_set'))
             THREAD_LOCALS.ebnf_grammar_singleton = grammar
         else:
-            grammar = EBNFGrammar()
+            grammar = EBNFGrammar(static_analysis=False)
             THREAD_LOCALS.ebnf_grammar_singleton = grammar
     if mode == 'configurable':
         # configure grammar on each request of the grammar object

DHParser/parse.py

@@ -1121,9 +1121,11 @@ class Grammar:
 
     def __init__(self, root: Parser = None, static_analysis: Optional[bool] = None) -> None:
         """Constructor of class Grammar.
-        :param root: Overrides default root parser. By default the root parser
-            is the parser assigned to the class field `root__`. This is useful for
-            executing or testing certain parts of a complex parser ensemble.
+        :param root: If not None, this is goind to be the root parser of the grammar.
+            This allows to first construct an ensemble of parser objects and then
+            link those objects in a grammar-object, rather than adding the parsers
+            as fields to a derived class of class Grammar. (See the doc-tests in this
+            module for examples.)
         :param static_analysis: If not None, this overrides the config value
             "static_analysis".
         """