- DHParser/confguration.py new module: centralizes all configuration values

DHParser/__init__.py

@@ -18,10 +18,12 @@ implied.  See the License for the specific language governing
 permissions and limitations under the License.
 """
 
+# Flat namespace for the DHParser Package. Is this a good idea...?
+
 from .compile import *
+from .configuration import *
 from .dsl import *
 from .ebnf import *
-# Flat namespace for the DHParser Package. Is this a good idea...?
 from .error import *
 from .log import *
 from .parse import *
@@ -37,4 +39,4 @@ name = "DHParser"
 __author__ = "Eckhart Arnold <arnold@badw.de>"
 __copyright__ = "http://www.apache.org/licenses/LICENSE-2.0"
 # __all__ = ['toolkit', 'stringview', 'error', 'syntaxtree', 'preprocess', 'parse',
-# 'transform', 'ebnf', 'dsl', 'testing', 'versionnumber']
+# 'transform', 'ebnf', 'dsl', 'testing', 'versionnumber', 'configuration']

DHParser/configuration.py

+# configuration.py - default configuration values for DHParser
+#
+# Copyright 2016  by Eckhart Arnold (arnold@badw.de)
+#                 Bavarian Academy of Sciences an Humanities (badw.de)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.  See the License for the specific language governing
+# permissions and limitations under the License.
+
+"""
+Module "configuration.py" defines the default configuration for DHParser.
+The configuration values can be changed while running via the
+DHParser.toolkit.get_config_value() and DHParser.toolkit.get_config_value()-
+functions.
+
+The presets can also be overwritten before(!) spawning any parsing processes by
+overwriting the values in the CONFIG_PRESET dictionary.
+
+The recommended way to use a different configuration in any custom code using
+DHParser is to use the second method, i.e. to overwrite the values for which
+this is desired in the CONFIG_PRESET dictionary right after the start of the
+programm and before any DHParser-function is invoked.
+"""
+
+from typing import Dict, Hashable, Any
+
+__all__ = ('CONFIG_PRESET',)
+
+CONFIG_PRESET = dict()  # type: Dict[Hashable, Any]
+
+
+# DHParser.ebnfy.EBNFCompiler class adds the the EBNF-grammar to the
+# docstring of the generated Grammar-class
+# Default value: False
+CONFIG_PRESET['add_grammar_source_to_parser_docstring'] = False
+
+# Flattens anonymous nodes, by removing the node and adding its childeren
+# to the parent node in place of the removed node. This is a very useful
+# optimization that should be truned on except for learning or teaching
+# purposes, in which case a concrete syntax tree that more diligently
+# reflects the parser structure may be helpful.
+CONFIG_PRESET['flatten_tree_while_parsing'] = True
+
+# Carries out static analysis on the the parser tree before parsing starts
+# to ensure its correctness. Possible values are:
+# 'early' - static analysis is carried out by DHParser.ebnf.EBNFCompiler,
+#           already. Any errors it revealed will be located in the EBNF
+#           source code. This naturally only works for parser that are
+#           generated from an EBNF syntax declaration.
+# 'late' -  static analysis is carried out when instantiating a Grammar
+#           (sub-)class. This works also for parser trees that are
+#           handwritten in Python using the parser classes from module
+#           `parse`. It slightly slows down instantiation of Grammar
+#           clasees, though.
+# 'none' -  no static analysis at all (not recommended).
+# Default value: "early"
+CONFIG_PRESET['static_analysis'] = "early"
+
+# Defines the output format for the serialization of syntax trees.
+# Possible values are:
+# 'XML'          - output as XML
+# 'S-expression' - output as S-expression, i.e. a list-like format
+# 'compact'      - compact tree output, i.e. children a represented
+#                  on indented lines with no opening or closing tags,
+#                  brackets etc.
+# Default values: "compact" for conctrete syntax trees and "XML" for
+#                 abstract syntax trees and "S-expression" for any
+#                 other kind of tree.
+CONFIG_PRESET['cst_serialization'] = "compact"
+CONFIG_PRESET['ast_serialization'] = "XML"
+CONFIG_PRESET['default_serialization'] = "S-expression"
+
+# Allows (coarse-grained) parallelization for running tests via the
+# Python multiprocessing module
+# Default value: True
+CONFIG_PRESET['test_parallelization'] = True

DHParser/ebnf.py

@@ -37,7 +37,8 @@ from DHParser.parse import Grammar, mixin_comment, Forward, RegExp, Whitespace,
 from DHParser.preprocess import nil_preprocessor, PreprocessorFunc
 from DHParser.syntaxtree import Node, WHITESPACE_PTYPE, TOKEN_PTYPE
 from DHParser.toolkit import load_if_file, escape_re, md5, sane_parser_name, re, expand_table, \
-    GLOBALS, CONFIG_PRESET, get_config_value, unrepr, compile_python_object, typing
+    GLOBALS, get_config_value, unrepr, compile_python_object, typing
+from DHParser.configuration import CONFIG_PRESET
 from DHParser.transform import TransformationFunc, traverse, remove_brackets, \
     reduce_single_child, replace_by_single_child, remove_expendables, \
     remove_tokens, flatten, forbid, assert_content
@@ -61,18 +62,6 @@ __all__ = ('get_ebnf_preprocessor',
            'CompilerFactoryFunc')
 
 
-########################################################################
-#
-# Presets
-#
-########################################################################
-
-CONFIG_PRESET['add_grammar_source_to_parser_docstring'] = False
-# CONFIG_PRESET['static_analysis'] = "early" # do a static analysis right
-#                                            # after ebnf compilation
-# already set in parse.py - config vars should probably moved to a
-#                           a dedicated global module
-
 ########################################################################
 #
 # source code support

DHParser/foreign_typing.LICENSE

-A. HISTORY OF THE SOFTWARE
-==========================
-
-Python was created in the early 1990s by Guido van Rossum at Stichting
-Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands
-as a successor of a language called ABC.  Guido remains Python's
-principal author, although it includes many contributions from others.
-
-In 1995, Guido continued his work on Python at the Corporation for
-National Research Initiatives (CNRI, see http://www.cnri.reston.va.us)
-in Reston, Virginia where he released several versions of the
-software.
-
-In May 2000, Guido and the Python core development team moved to
-BeOpen.com to form the BeOpen PythonLabs team.  In October of the same
-year, the PythonLabs team moved to Digital Creations (now Zope
-Corporation, see http://www.zope.com).  In 2001, the Python Software
-Foundation (PSF, see http://www.python.org/psf/) was formed, a
-non-profit organization created specifically to own Python-related
-Intellectual Property.  Zope Corporation is a sponsoring member of
-the PSF.
-
-All Python releases are Open Source (see http://www.opensource.org for
-the Open Source Definition).  Historically, most, but not all, Python
-releases have also been GPL-compatible; the table below summarizes
-the various releases.
-
-    Release         Derived     Year        Owner       GPL-
-                    from                                compatible? (1)
-
-    0.9.0 thru 1.2              1991-1995   CWI         yes
-    1.3 thru 1.5.2  1.2         1995-1999   CNRI        yes
-    1.6             1.5.2       2000        CNRI        no
-    2.0             1.6         2000        BeOpen.com  no
-    1.6.1           1.6         2001        CNRI        yes (2)
-    2.1             2.0+1.6.1   2001        PSF         no
-    2.0.1           2.0+1.6.1   2001        PSF         yes
-    2.1.1           2.1+2.0.1   2001        PSF         yes
-    2.1.2           2.1.1       2002        PSF         yes
-    2.1.3           2.1.2       2002        PSF         yes
-    2.2 and above   2.1.1       2001-now    PSF         yes
-
-Footnotes:
-
-(1) GPL-compatible doesn't mean that we're distributing Python under
-    the GPL.  All Python licenses, unlike the GPL, let you distribute
-    a modified version without making your changes open source.  The
-    GPL-compatible licenses make it possible to combine Python with
-    other software that is released under the GPL; the others don't.
-
-(2) According to Richard Stallman, 1.6.1 is not GPL-compatible,
-    because its license has a choice of law clause.  According to
-    CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1
-    is "not incompatible" with the GPL.
-
-Thanks to the many outside volunteers who have worked under Guido's
-direction to make these releases possible.
-
-
-B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON
-===============================================================
-
-PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
---------------------------------------------
-
-1. This LICENSE AGREEMENT is between the Python Software Foundation
-("PSF"), and the Individual or Organization ("Licensee") accessing and
-otherwise using this software ("Python") in source or binary form and
-its associated documentation.
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-2. Subject to the terms and conditions of this License Agreement, PSF hereby
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-CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1
----------------------------------------
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-CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2
---------------------------------------------------
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-Copyright (c) 1991 - 1995, Stichting Mathematisch Centrum Amsterdam,
-The Netherlands.  All rights reserved.
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DHParser/parse.py

@@ -39,8 +39,9 @@ from DHParser.preprocess import BEGIN_TOKEN, END_TOKEN, RX_TOKEN_NAME
 from DHParser.stringview import StringView, EMPTY_STRING_VIEW
 from DHParser.syntaxtree import Node, FrozenNode, RootNode, WHITESPACE_PTYPE, \
     TOKEN_PTYPE, ZOMBIE_TAG, ResultType
-from DHParser.toolkit import sane_parser_name, escape_control_characters, get_config_value,\
-    CONFIG_PRESET, re, typing, cython
+from DHParser.toolkit import sane_parser_name, escape_control_characters, get_config_value, \
+    re, typing, cython
+from DHParser.configuration import CONFIG_PRESET
 from typing import Callable, cast, List, Tuple, Set, Dict, DefaultDict, Union, Optional, Any
 
 
@@ -85,20 +86,6 @@ __all__ = ('Parser',
            'Forward')
 
 
-########################################################################
-#
-# Presets
-#
-########################################################################
-
-CONFIG_PRESET['flatten_tree_while_parsing'] = True
-CONFIG_PRESET['static_analysis'] = "early"
-# 'early': do static analysis already when compiling and EBNF grammar, see ebnf.py
-# 'late': do a static analysis, the first time a grammar class is instantiated
-# 'none': no static analysis of the grammar
-# TODO:  move all presests to a dedicated configuration module
-
-
 ########################################################################
 #
 # Parser base class

DHParser/syntaxtree.py

@@ -28,7 +28,7 @@ import copy
 
 from DHParser.error import Error, ErrorCode, linebreaks, line_col
 from DHParser.stringview import StringView
-from DHParser.toolkit import re
+from DHParser.toolkit import get_config_value, re
 from typing import Callable, cast, Iterator, List, AbstractSet, Set, Union, Tuple, Optional
 
 
@@ -40,6 +40,7 @@ __all__ = ('WHITESPACE_PTYPE',
            'StrictResultType',
            'ChildrenType',
            'Node',
+           'serialize',
            'FrozenNode',
            'tree_sanity_check',
            'RootNode',
@@ -731,6 +732,33 @@ class Node:  # (collections.abc.Sized): Base class omitted for cython-compatibil
         return sum(child.tree_size() for child in self.children) + 1
 
 
+def serialize(node: Node, how: str='default') -> str:
+    """
+    Serializes the tree starting with `node` either as S-expression, XML
+    or in compact form. Possible values for `how` are 'S-expression',
+    'XML', 'compact' accordingly, or 'AST', 'CST', 'default' in which case
+    the value of respective configuration variable determines the
+    serialization format. (See module `configuration.py`.)
+    """
+    switch = how.lower()
+
+    if switch == 'ast':
+        switch = get_config_value('ast_serialization').lower()
+    elif switch == 'cst':
+        switch = get_config_value('cst_serialization').lower()
+    elif switch == 'default':
+        switch = get_config_value('default_serialization').lower()
+
+    if switch == 's-expression':
+        return node.as_sxpr()
+    elif switch == 'xml':
+        return node.as_xml()
+    elif switch == 'compact':
+        return node.as_sxpr(compact=True)
+    else:
+        raise ValueError('Unknown serialization %s, %s' % (how, switch))
+
+
 class FrozenNode(Node):
     """
     FrozenNode is an immutable kind of Node, i.e. it must not be changed

DHParser/testing.py

@@ -28,7 +28,6 @@ main cause of trouble when constructing a context free Grammar.
 
 import collections
 import concurrent.futures
-# import configparser
 import copy
 import fnmatch
 import inspect
@@ -36,14 +35,14 @@ import json
 import multiprocessing
 import os
 import sys
+from typing import Dict, List, Union, cast
 
 from DHParser.error import Error, is_error, adjust_error_locations
 from DHParser.log import is_logging, clear_logs, log_parsing_history
 from DHParser.parse import UnknownParserError, Parser, Lookahead
-from DHParser.syntaxtree import Node, RootNode, parse_tree, flatten_sxpr, ZOMBIE_TAG
-from DHParser.toolkit import load_if_file, re, typing
+from DHParser.syntaxtree import Node, RootNode, parse_tree, flatten_sxpr, serialize, ZOMBIE_TAG
+from DHParser.toolkit import get_config_value, set_config_value, load_if_file, re
 
-from typing import Dict, List, Union, cast
 
 __all__ = ('unit_from_config',
            'unit_from_json',
@@ -262,10 +261,10 @@ def get_report(test_unit):
             cst = tests.get('__cst__', {}).get(test_name, None)
             if cst and (not ast or str(test_name).endswith('*')):
                 report.append('\n### CST')
-                report.append(indent(cst.as_sxpr(compact=True)))
+                report.append(indent(serialize(cst, 'cst')))
             if ast:
                 report.append('\n### AST')
-                report.append(indent(ast.as_xml()))
+                report.append(indent(serialize(ast, 'ast')))
         for test_name, test_code in tests.get('fail', dict()).items():
             heading = 'Fail-test "%s"' % test_name
             report.append('\n%s\n%s\n' % (heading, '-' * len(heading)))
@@ -408,7 +407,7 @@ def grammar_unit(test_unit, parser_factory, transformer_factory, report=True, ve
                 if compare:
                     if not compare.equals(cst):
                         errata.append('Concrete syntax tree test "%s" for parser "%s" failed:\n%s' %
-                                      (test_name, parser_name, cst.as_sxpr()))
+                                      (test_name, parser_name, serialize(cst, 'cst')))
                     if verbose:
                         infostr = '      cst-test "' + test_name + '" ... '
                         write(infostr + ("OK" if len(errata) == errflag else "FAIL"))
@@ -502,21 +501,33 @@ def grammar_suite(directory, parser_factory, transformer_factory,
     os.chdir(directory)
     if is_logging():
         clear_logs()
-    with concurrent.futures.ProcessPoolExecutor(multiprocessing.cpu_count()) as pool:
-        errata_futures = []
-        for filename in sorted(os.listdir()):
+
+    if get_config_value('test_parallelization'):
+        with concurrent.futures.ProcessPoolExecutor(multiprocessing.cpu_count()) as pool:
+            results = []
+            for filename in sorted(os.listdir('.')):
+                if any(fnmatch.fnmatch(filename, pattern) for pattern in fn_patterns):
+                    parameters = filename, parser_factory, transformer_factory, report, verbose
+                    results.append((filename, pool.submit(grammar_unit, *parameters)))
+                    # grammar_unit(*parameters)
+            for filename, err_future in results:
+                try:
+                    errata = err_future.result()
+                    if errata:
+                        all_errors[filename] = errata
+                except ValueError as e:
+                    if not ignore_unknown_filetypes or str(e).find("Unknown") < 0:
+                        raise e
+    else:
+        results = []
+        for filename in sorted(os.listdir('.')):
             if any(fnmatch.fnmatch(filename, pattern) for pattern in fn_patterns):
                 parameters = filename, parser_factory, transformer_factory, report, verbose
-                errata_futures.append((filename, pool.submit(grammar_unit, *parameters)))
-                # grammar_unit(*parameters)
-        for filename, err_future in errata_futures:
-            try:
-                errata = err_future.result()
-                if errata:
-                    all_errors[filename] = errata
-            except ValueError as e:
-                if not ignore_unknown_filetypes or str(e).find("Unknown") < 0:
-                    raise e
+                results.append((filename, grammar_unit(*parameters)))
+        for filename, errata in results:
+            if errata:
+                all_errors[filename] = errata
+
     os.chdir(save_cwd)
     error_report = []
     err_N = 0
@@ -760,15 +771,21 @@ def run_path(path):
         sys.path.append(path)
         files = os.listdir(path)
         result_futures = []
-        with concurrent.futures.ProcessPoolExecutor(multiprocessing.cpu_count()) as pool:
+
+        if get_config_value('test_parallelization'):
+            with concurrent.futures.ProcessPoolExecutor(multiprocessing.cpu_count()) as pool:
+                for f in files:
+                    result_futures.append(pool.submit(run_file, f))
+                    # run_file(f)  # for testing!
+                for r in result_futures:
+                    try:
+                        _ = r.result()
+                    except AssertionError as failure:
+                        print(failure)
+        else:
             for f in files:
-                result_futures.append(pool.submit(run_file, f))
-                # run_file(f)  # for testing!
-            for r in result_futures:
-                try:
-                    _ = r.result()
-                except AssertionError as failure:
-                    print(failure)
+                run_file(f)
+
     else:
         path, fname = os.path.split(path)
         sys.path.append(path)

DHParser/toolkit.py

@@ -22,7 +22,6 @@ several of the the other DHParser-Modules or that are just very generic
 so that they are best defined in a toolkit-module.
 """
 
-import codecs
 import hashlib
 import io
 import multiprocessing
@@ -34,14 +33,8 @@ try:
 except ImportError:
     import re
 import sys
-
-try:
-    import typing
-except ImportError:
-    import DHParser.foreign_typing as typing
-    sys.modules['typing'] = typing  # make it possible to import from typing
-
-from typing import Any, Iterable, Sequence, Set, Union, Dict, Hashable, cast
+import typing
+from typing import Any, Iterable, Sequence, Set, Union, Dict, Hashable
 
 try:
     import cython
@@ -52,6 +45,8 @@ except ImportError:
     cython_optimized = False            # type: bool
     import DHParser.shadow_cython as cython
 
+from DHParser.configuration import CONFIG_PRESET