- toolkit.py: added context manager for supression of warnings

DHParser/ebnf.py

@@ -16,15 +16,16 @@ implied.  See the License for the specific language governing
 permissions and limitations under the License.
 """
 
-from collections import OrderedDict
 import keyword
+from collections import OrderedDict
+
 try:
     import regex as re
 except ImportError:
     import re
 from typing import Callable, Dict, List, Set, Tuple
 
-from DHParser.toolkit import load_if_file, escape_re, md5, sane_parser_name
+from DHParser.toolkit import load_if_file, escape_re, md5, sane_parser_name, warnings
 from DHParser.parsers import Grammar, mixin_comment, nil_scanner, Forward, RE, NegativeLookahead, \
     Alternative, Sequence, Optional, Required, OneOrMore, ZeroOrMore, Token, Compiler, \
     ScannerFunc
@@ -439,17 +440,19 @@ class EBNFCompiler(Compiler):
 
         # check for unconnected rules
 
-        defined_symbols.difference_update(self.RESERVED_SYMBOLS)
-
-        def remove_connections(symbol):
-            if symbol in defined_symbols:
-                defined_symbols.remove(symbol)
-                for related in self.rules[symbol][1:]:
-                    remove_connections(str(related))
-        remove_connections(self.root)
-        for leftover in defined_symbols:
-            self.rules[leftover][0].add_error(('Rule "%s" is not connected to parser '
-                                               'root "%s"') % (leftover, self.root))
+        if warnings():
+            defined_symbols.difference_update(self.RESERVED_SYMBOLS)
+
+            def remove_connections(symbol):
+                if symbol in defined_symbols:
+                    defined_symbols.remove(symbol)
+                    for related in self.rules[symbol][1:]:
+                        remove_connections(str(related))
+
+            remove_connections(self.root)
+            for leftover in defined_symbols:
+                self.rules[leftover][0].add_error(('Rule "%s" is not connected to parser '
+                                                   'root "%s"') % (leftover, self.root))
 
         # set root parser and assemble python grammar definition
 

DHParser/parsers.py

@@ -487,7 +487,7 @@ def dsl_error_msg(parser: Parser, error_str: str) -> str:
         str: An error message including the call stack if history 
         tacking has been turned in the grammar object.
     """
-    msg = ["DSL parser specification error:", error_str, "caught by parser", str(parser)]
+    msg = ["DSL parser specification error:", error_str, 'Caught by parser "%s".' % str(parser)]
     if parser.grammar.history:
         msg.extend(["\nCall stack:", parser.grammar.history[-1].stack])
     else:
@@ -768,7 +768,7 @@ class Optional(UnaryOperator):
         super(Optional, self).__init__(parser, name)
         # assert isinstance(parser, Parser)
         assert not isinstance(parser, Optional), \
-            "Nesting options would be redundant: %s(%s)" % \
+            "Redundant nesting of options: %s(%s)" % \
             (str(name), str(parser.name))
         assert not isinstance(parser, Required), \
             "Nesting options with required elements is contradictory: " \

DHParser/testing.py

@@ -237,9 +237,10 @@ def grammar_unit(test_unit, parser_factory, transformer_factory, verbose=False):
                 transform(ast)
                 tests.setdefault('__ast__', {})[test_name] = ast
             if cst.error_flag:
-                errata.append('Match test "%s" for parser "%s" failed:\n\tExpr.:  %s\n\t%s' %
+                errata.append('Match test "%s" for parser "%s" failed:\n\tExpr.:  %s\n\n\t%s' %
                               (test_name, parser_name, '\n\t'.join(test_code.split('\n')),
-                               '\n\t'.join(error_messages(test_code, cst.collect_errors()))))
+                               '\n\t'.join(m.replace('\n', '\n\t\t') for m in
+                                           error_messages(test_code, cst.collect_errors()))))
                 tests.setdefault('__err__', {})[test_name] = errata[-1]
             elif "cst" in tests and mock_syntax_tree(tests["cst"][test_name]) != cst:
                     errata.append('Concrete syntax tree test "%s" for parser "%s" failed:\n%s' %

DHParser/toolkit.py

@@ -45,6 +45,8 @@ __all__ = ['logging',
            'is_logging',
            'log_dir',
            'logfile_basename',
+           'supress_warnings',
+           'warnings',
            'line_col',
            'error_messages',
            'compact_sexpr',
@@ -97,7 +99,7 @@ def log_dir() -> str:
 
 
 @contextlib.contextmanager
-def logging(dirname="LOGS"):
+def logging(dirname: str = "LOGS"):
     """Context manager. Log files within this context will be stored in
     directory ``dirname``. Logging is turned off if name is empty.
     
@@ -116,7 +118,7 @@ def logging(dirname="LOGS"):
     LOGGING = save
 
 
-def is_logging():
+def is_logging() -> bool:
     """-> True, if logging is turned on."""
     global LOGGING
     try:
@@ -125,6 +127,26 @@ def is_logging():
         return False
 
 
+@contextlib.contextmanager
+def supress_warnings(supress: bool = True):
+    global SUPRESS_WARNINGS
+    try:
+        save = SUPRESS_WARNINGS
+    except NameError:
+        save = False  # global default for warning supression is False
+    SUPRESS_WARNINGS = supress
+    yield
+    SUPRESS_WARNINGS = save
+
+
+def warnings() -> bool:
+    global SUPRESS_WARNINGS
+    try:
+        return not SUPRESS_WARNINGS
+    except NameError:
+        return True
+
+
 def line_col(text: str, pos: int) -> Tuple[int, int]:
     """Returns the position within a text as (line, column)-tuple.
     """

examples/LaTeX/LaTeX.ebnf

@@ -6,7 +6,7 @@
 latexdoc   = preamble document
 preamble   = { command }+
 
-document   = { [PARSEP] paragraph } [PARSEP] §EOF
+document   = [PARSEP] sequence [PARSEP] §EOF
 
 genericenv = beginenv sequence §endenv
 beginenv   = "\begin" §( "{" NAME "}" )
@@ -38,9 +38,9 @@ ESCAPED    = /\\[%$&]/
 BRACKETS   = /[\[\]]/                   # left or right square bracket: [ ]
 TEXTCHUNK  = /[^\\%$&\{\}\[\]\s\n]+/    # some piece of text excluding whitespace,
                                         # linefeed and special characters
-WSPC       = /[ \t]*\n?(?!\s*\n)[ \t]*/ # whitespace, including at most one linefeed
+WSPC       = /[ \t]*\n?(?![ \t]*\n)[ \t]*/ # whitespace, including at most one linefeed
 LF         = /[ \t]*\n(?!\s*\n)/        # a linefeed, but not an empty line (i.e. par)
-PARSEP     = /\s*\n\s*\n/               # at least one empty line, i.e.
+PARSEP     = /\n[ \t]*(?=\n)/~          # at least one empty line, i.e.
                                         # [whitespace] linefeed [whitespace] linefeed
 
 EOF        = !/./

examples/LaTeX/recompile_grammar.py

@@ -25,4 +25,7 @@ import sys
 sys.path.extend(['../../', '../', './'])
 
 from DHParser.testing import recompile_grammar
-recompile_grammar('.', True)
+from DHParser.toolkit import supress_warnings
+
+with supress_warnings(True):
+    recompile_grammar('.', True)

examples/LaTeX/tst_grammar.py

@@ -27,7 +27,8 @@ from DHParser import toolkit
 from LaTeXCompiler import get_grammar, get_transformer
 
 with toolkit.logging(True):
-    error_report = testing.grammar_suite('grammar_tests', get_grammar, get_transformer, verbose=True)
+    error_report = testing.grammar_suite('grammar_tests', get_grammar,
+                                         get_transformer, verbose=True)
 assert not error_report, error_report
 
 

examples/Tutorial/Lyrisches_Intermezzo_IV.txt

@@ -14,4 +14,4 @@ so werd' ich ganz und gar gesund.
 Wenn ich mich lehn' an deine Brust,
 kommt's über mich wie Himmelslust,
 doch wenn du sprichst: Ich liebe dich!
-so muß ich weinen bitterlich.
+so muß ich weinen bitterlich.
\ No newline at end of file

examples/Tutorial/recompile_grammar.py

@@ -25,4 +25,5 @@ import sys
 sys.path.extend(['../../', '../', './'])
 
 from DHParser.testing import recompile_grammar
-recompile_grammar('.')
+
+recompile_grammar('.', force=True)