Merge branch 'master' of gitlab.lrz.de:badw-it/DHParser

.gitignore

@@ -22,3 +22,4 @@ build/
 dist/
 MANIFEST
 playground/*
+DevScripts/DHParser.py

DHParser/__init__.py

@@ -18,6 +18,7 @@ implied.  See the License for the specific language governing
 permissions and limitations under the License.
 """
 
+from .base import *
 from .dsl import *
 from .ebnf import *
 from .parser import *
@@ -30,4 +31,4 @@ from .versionnumber import __version__
 
 __author__ = "Eckhart Arnold <arnold@badw.de>"
 __copyright__ = "http://www.apache.org/licenses/LICENSE-2.0"
-# __all__ = ['toolkit', 'syntaxtree', 'parser', 'transform', 'ebnf', 'dsl', 'testing', 'versionnumber']  # flat namespace
+# __all__ = ['toolkit', 'base', 'syntaxtree', 'parser', 'transform', 'ebnf', 'dsl', 'testing', 'versionnumber']  # flat namespace

DHParser/base.py

+"""base.py - various base classes that are used across several other
+             the DHParser-modules.
+
+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.
+"""
+import collections
+from typing import Hashable, Iterable, Iterator, Optional, Tuple
+
+
+__all__ = ('ParserBase',
+           'WHITESPACE_PTYPE',
+           'TOKEN_PTYPE',
+           'MockParser',
+           'ZombieParser',
+           'ZOMBIE_PARSER',
+           'Error',
+           'is_error',
+           'is_warning',
+           'has_errors',
+           'only_errors',
+           'StringView',
+           'EMPTY_STRING_VIEW')
+
+
+#######################################################################
+#
+# parser base and mock parsers
+#
+#######################################################################
+
+
+class ParserBase:
+    """
+    ParserBase is the base class for all real and mock parser classes.
+    It is defined here, because Node objects require a parser object
+    for instantiation.
+    """
+    def __init__(self, name=''):  # , pbases=frozenset()):
+        self.name = name  # type: str
+        self._ptype = ':' + self.__class__.__name__  # type: str
+
+    def __repr__(self):
+        return self.name + self.ptype
+
+    def __str__(self):
+        return self.name + (' = ' if self.name else '') + repr(self)
+
+    @property
+    def ptype(self) -> str:
+        return self._ptype
+
+    @property
+    def repr(self) -> str:
+        return self.name if self.name else repr(self)
+
+
+WHITESPACE_PTYPE = ':Whitespace'
+TOKEN_PTYPE = ':Token'
+
+
+class MockParser(ParserBase):
+    """
+    MockParser objects can be used to reconstruct syntax trees from a
+    serialized form like S-expressions or XML. Mock objects can mimic
+    different parser types by assigning them a ptype on initialization.
+
+    Mock objects should not be used for anything other than
+    syntax tree (re-)construction. In all other cases where a parser
+    object substitute is needed, chose the singleton ZOMBIE_PARSER.
+    """
+    def __init__(self, name='', ptype=''):  # , pbases=frozenset()):
+        assert not ptype or ptype[0] == ':'
+        super(MockParser, self).__init__(name)
+        self.name = name
+        self._ptype = ptype or ':' + self.__class__.__name__
+
+
+class ZombieParser(MockParser):
+    """
+    Serves as a substitute for a Parser instance.
+
+    ``ZombieParser`` is the class of the singelton object
+    ``ZOMBIE_PARSER``. The  ``ZOMBIE_PARSER`` has a name and can be
+    called, but it never matches. It serves as a substitute where only
+    these (or one of these properties) is needed, but no real Parser-
+    object is instantiated.
+    """
+    alive = False
+
+    def __init__(self):
+        super(ZombieParser, self).__init__("__ZOMBIE__")
+        assert not self.__class__.alive, "There can be only one!"
+        assert self.__class__ == ZombieParser, "No derivatives, please!"
+        self.__class__.alive = True
+
+    def __copy__(self):
+        return self
+
+    def __deepcopy__(self, memo):
+        return self
+
+    def __call__(self, text):
+        """Better call Saul ;-)"""
+        return None, text
+
+
+ZOMBIE_PARSER = ZombieParser()
+
+
+#######################################################################
+#
+# error reporting
+#
+#######################################################################
+
+
+class Error:
+    __slots__ = ['message', 'level', 'code', 'pos', 'line', 'column']
+
+    WARNING   = 1
+    ERROR     = 1000
+    HIGHEST   = ERROR
+
+    def __init__(self, message: str, level: int=ERROR, code: Hashable=0):
+        self.message = message
+        assert level >= 0
+        self.level = level or Error.ERROR
+        self.code = code
+        self.pos = -1
+        self.line = -1
+        self.column = -1
+
+    def __str__(self):
+        prefix = ''
+        if self.line > 0:
+            prefix = "line: %3i, column: %2i, " % (self.line, self.column)
+        return prefix + "%s: %s" % (self.level_str, self.message)
+
+    @property
+    def level_str(self):
+        return "Warning" if is_warning(self.level) else "Error"
+
+
+def is_warning(level: int) -> bool:
+    return level < Error.ERROR
+
+
+def is_error(level:  int) -> bool:
+    return level >= Error.ERROR
+
+
+def has_errors(messages: Iterable[Error], level: int=Error.ERROR) -> bool:
+    """
+    Returns True, if at least one entry in `messages` has at
+    least the given error `level`.
+    """
+    for err_obj in messages:
+        if err_obj.level >= level:
+            return True
+    return False
+
+
+def only_errors(messages: Iterable[Error], level: int=Error.ERROR) -> Iterator[Error]:
+    """
+    Returns an Iterator that yields only those messages that have
+    at least the given error level.
+    """
+    return (err for err in messages if err.level >= level)
+
+
+#######################################################################
+#
+# string view
+#
+#######################################################################
+
+
+class StringView(collections.abc.Sized):
+    """"A rudimentary StringView class, just enough for the use cases
+    in parser.py.
+
+    Slicing Python-strings always yields copies of a segment of the original
+    string. See: https://mail.python.org/pipermail/python-dev/2008-May/079699.html
+    However, this becomes costly (in terms of space and as a consequence also
+    time) when parsing longer documents. Unfortunately, Python's `memoryview`
+    does not work for unicode strings. Hence, the StringView class.
+    """
+
+    __slots__ = ['text', 'begin', 'end', 'len', 'fullstring_flag']
+
+    def __init__(self, text: str, begin: Optional[int] = 0, end: Optional[int] = None) -> None:
+        self.text = text  # type: str
+        self.begin = 0  # type: int
+        self.end = 0    # type: int
+        self.begin, self.end = StringView.real_indices(begin, end, len(text))
+        self.len = max(self.end - self.begin, 0)
+        self.fullstring_flag = (self.begin == 0 and self.len == len(self.text))
+
+    @staticmethod
+    def real_indices(begin, end, len):
+        def pack(index, len):
+            index = index if index >= 0 else index + len
+            return 0 if index < 0 else len if index > len else index
+        if begin is None:  begin = 0
+        if end is None:  end = len
+        return pack(begin, len), pack(end, len)
+
+    def __bool__(self):
+        return bool(self.text) and self.end > self.begin
+
+    def __len__(self):
+        return self.len
+
+    def __str__(self):
+        if self.fullstring_flag:  # optimization: avoid slicing/copying
+            return self.text
+        return self.text[self.begin:self.end]
+
+    def __getitem__(self, index):
+        # assert isinstance(index, slice), "As of now, StringView only allows slicing."
+        # assert index.step is None or index.step == 1, \
+        #     "Step sizes other than 1 are not yet supported by StringView"
+        start, stop = StringView.real_indices(index.start, index.stop, self.len)
+        return StringView(self.text, self.begin + start, self.begin + stop)
+
+    def __eq__(self, other):
+        return str(self) == str(other)  # PERFORMANCE WARNING: This creates copies of the strings
+
+    def count(self, sub, start=None, end=None) -> int:
+        if self.fullstring_flag:
+            return self.text.count(sub, start, end)
+        elif start is None and end is None:
+            return self.text.count(sub, self.begin, self.end)
+        else:
+            start, end = StringView.real_indices(start, end, self.len)
+            return self.text.count(sub, self.begin + start, self.begin + end)
+
+    def find(self, sub, start=None, end=None) -> int:
+        if self.fullstring_flag:
+            return self.text.find(sub, start, end)
+        elif start is None and end is None:
+            return self.text.find(sub, self.begin, self.end) - self.begin
+        else:
+            start, end = StringView.real_indices(start, end, self.len)
+            return self.text.find(sub, self.begin + start, self.begin + end) - self.begin
+
+    def rfind(self, sub, start=None, end=None) -> int:
+        if self.fullstring_flag:
+            return self.text.rfind(sub, start, end)
+        if start is None and end is None:
+            return self.text.rfind(sub, self.begin, self.end) - self.begin
+        else:
+            start, end = StringView.real_indices(start, end, self.len)
+            return self.text.rfind(sub, self.begin + start, self.begin + end) - self.begin
+
+    def startswith(self, prefix: str, start:int = 0, end:Optional[int] = None) -> bool:
+        start += self.begin
+        end = self.end if end is None else self.begin + end
+        return self.text.startswith(prefix, start, end)
+
+    def match(self, regex):
+        return regex.match(self.text, pos=self.begin, endpos=self.end)
+
+    def index(self, absolute_index: int) -> int:
+        """
+        Converts an index for a string watched by a StringView object
+        to an index relative to the string view object, e.g.:
+        >>> sv = StringView('xxIxx')[2:3]
+        >>> match = sv.match(re.compile('I'))
+        >>> match.end()
+        3
+        >>> sv.index(match.end())
+        1
+        """
+        return absolute_index - self.begin
+
+    def indices(self, absolute_indices: Iterable[int]) -> Tuple[int, ...]:
+        """Converts indices for a string watched by a StringView object
+        to indices relative to the string view object. See also: `sv_index()`
+        """
+        return tuple(index - self.begin for index in absolute_indices)
+
+    def search(self, regex):
+        return regex.search(self.text, pos=self.begin, endpos=self.end)
+
+
+EMPTY_STRING_VIEW = StringView('')
\ No newline at end of file

DHParser/dsl.py

@@ -15,7 +15,7 @@ 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 ``DSLsupport`` contains various functions to support the
+Module ``dsl`` contains various functions to support the
 compilation of domain specific languages based on an EBNF-grammar.
 """
 
@@ -26,9 +26,9 @@ try:
 except ImportError:
     import re
 try:
-    from typing import Any, cast, Tuple, Union, Iterable
+    from typing import Any, cast, Tuple, Union, Iterator, Iterable
 except ImportError:
-    from .typing34 import Any, cast, Tuple, Union, Iterable
+    from .typing34 import Any, cast, Tuple, Union, Iterator, Iterable
 
 from DHParser.ebnf import EBNFCompiler, grammar_changed, \
     get_ebnf_preprocessor, get_ebnf_grammar, get_ebnf_transformer, get_ebnf_compiler, \
@@ -36,6 +36,7 @@ from DHParser.ebnf import EBNFCompiler, grammar_changed, \
 from DHParser.toolkit import logging, load_if_file, is_python_code, compile_python_object
 from DHParser.parser import Grammar, Compiler, compile_source, nil_preprocessor, PreprocessorFunc
 from DHParser.syntaxtree import Node, TransformationFunc
+from DHParser.base import Error, is_error, has_errors, only_errors
 
 __all__ = ('GrammarError',
            'CompilationError',
@@ -120,31 +121,48 @@ if __name__ == "__main__":
 '''
 
 
-class GrammarError(Exception):
+class DSLException(Exception):
+    """
+    Base class for DSL-exceptions.
+    """
+    def __init__(self, errors):
+        assert isinstance(errors, Iterator) or isinstance(errors, list) \
+               or isinstance(errors, tuple)
+        self.errors = errors
+
+    def __str__(self):
+        return '\n'.join(str(err) for err in self.errors)
+
+
+class GrammarError(DSLException):
     """
     Raised when (already) the grammar of a domain specific language (DSL)
     contains errors.
     """
-
-    def __init__(self, error_messages, grammar_src):
-        self.error_messages = error_messages
+    def __init__(self, errors, grammar_src):
+        super().__init__(errors)
         self.grammar_src = grammar_src
 
 
-class CompilationError(Exception):
+class CompilationError(DSLException):
     """
     Raised when a string or file in a domain specific language (DSL)
     contains errors.
     """
-    def __init__(self, error_messages, dsl_text, dsl_grammar, AST, result):
-        self.error_messages = error_messages
+    def __init__(self, errors, dsl_text, dsl_grammar, AST, result):
+        super().__init__(errors)
         self.dsl_text = dsl_text
         self.dsl_grammar = dsl_grammar
         self.AST = AST
         self.result = result
 
-    def __str__(self):
-        return '\n'.join(self.error_messages)
+
+def error_str(messages: Iterable[Error]) -> str:
+    """
+    Returns all true errors (i.e. not just warnings) from the
+    `messages` as a concatenated multiline string.
+    """
+    return '\n\n'.join(str(m) for m in  messages if is_error(m.level))
 
 
 def grammar_instance(grammar_representation) -> Tuple[Grammar, str]:
@@ -158,13 +176,13 @@ def grammar_instance(grammar_representation) -> Tuple[Grammar, str]:
         # read grammar
         grammar_src = load_if_file(grammar_representation)
         if is_python_code(grammar_src):
-            parser_py, errors, AST = grammar_src, '', None
+            parser_py, messages, AST = grammar_src, [], None
         else:
             with logging(False):
-                parser_py, errors, AST = compile_source(grammar_src, None,
+                parser_py, messages, AST = compile_source(grammar_src, None,
                     get_ebnf_grammar(), get_ebnf_transformer(), get_ebnf_compiler())
-        if errors:
-            raise GrammarError('\n\n'.join(errors), grammar_src)
+        if has_errors(messages):
+            raise GrammarError(only_errors(messages), grammar_src)
         parser_root = compile_python_object(DHPARSER_IMPORTS + parser_py, '\w+Grammar$')()
     else:
         # assume that dsl_grammar is a ParserHQ-object or Grammar class
@@ -194,11 +212,11 @@ def compileDSL(text_or_file: str,
     assert isinstance(compiler, Compiler)
 
     parser, grammar_src = grammar_instance(dsl_grammar)
-    result, errors, AST = compile_source(text_or_file, preprocessor, parser,
+    result, messages, AST = compile_source(text_or_file, preprocessor, parser,
                                          ast_transformation, compiler)
-    if errors:
+    if has_errors(messages):
         src = load_if_file(text_or_file)
-        raise CompilationError(errors, src, grammar_src, AST, result)
+        raise CompilationError(only_errors(messages), src, grammar_src, AST, result)
     return result
 
 
@@ -298,10 +316,10 @@ def load_compiler_suite(compiler_suite: str) -> \
     else:
         # assume source is an ebnf grammar. Is there really any reasonable application case for this?
         with logging(False):
-            compile_py, errors, AST = compile_source(source, None,
+            compile_py, messages, AST = compile_source(source, None,
                 get_ebnf_grammar(), get_ebnf_transformer(), get_ebnf_compiler())
-        if errors:
-            raise GrammarError('\n\n'.join(errors), source)
+        if has_errors(messages):
+            raise GrammarError(only_errors(messages), source)
         preprocessor = get_ebnf_preprocessor
         parser = get_ebnf_grammar
         ast = get_ebnf_transformer
@@ -388,8 +406,7 @@ def compile_on_disk(source_file: str, compiler_suite="", extension=".xml"):
             extension.
             
     Returns:
-        A list of error messages or an empty list if there were no 
-        errors. 
+        A (potentially empty) list of error or warning messages.
     """
     filepath = os.path.normpath(source_file)
     # with open(source_file, encoding="utf-8") as f:
@@ -405,9 +422,9 @@ def compile_on_disk(source_file: str, compiler_suite="", extension=".xml"):
         cfactory = get_ebnf_compiler
     compiler1 = cfactory()
     compiler1.set_grammar_name(compiler_name, source_file)
-    result, errors, ast = compile_source(source_file, sfactory(), pfactory(), tfactory(), compiler1)
-    if errors:
-        return errors
+    result, messages, ast = compile_source(source_file, sfactory(), pfactory(), tfactory(), compiler1)
+    if has_errors(messages):
+        return messages
 
     elif cfactory == get_ebnf_compiler:  # trans == get_ebnf_transformer or trans == EBNFTransformer:  # either an EBNF- or no compiler suite given
         ebnf_compiler = cast(EBNFCompiler, compiler1)
@@ -484,7 +501,7 @@ def compile_on_disk(source_file: str, compiler_suite="", extension=".xml"):
         finally:
             if f:  f.close()
 
-    return []
+    return messages
 
 
 def recompile_grammar(ebnf_filename, force=False) -> bool:
@@ -511,19 +528,20 @@ def recompile_grammar(ebnf_filename, force=False) -> bool:
     base, ext = os.path.splitext(ebnf_filename)
     compiler_name = base + 'Compiler.py'
     error_file_name = base + '_ebnf_ERRORS.txt'
-    errors = []  # type: Iterable[str]
+    messages = []  # type: Iterable[str]
     if (not os.path.exists(compiler_name) or force or
             grammar_changed(compiler_name, ebnf_filename)):
         # print("recompiling parser for: " + ebnf_filename)
-        errors = compile_on_disk(ebnf_filename)
-        if errors:
+        messages = compile_on_disk(ebnf_filename)
+        if messages:
             # print("Errors while compiling: " + ebnf_filename + '!')
-            with open(error_file_name, 'w') as f:
-                for e in errors:
-                    f.write(e)
+            with open(error_file_name, 'w', encoding="UTF-8") as f:
+                for e in messages:
+                    f.write(str(e))
                     f.write('\n')
-            return False
+            if has_errors(messages):
+                return False
 
-    if not errors and os.path.exists(error_file_name):
+    if not messages and os.path.exists(error_file_name):
         os.remove(error_file_name)
     return True

DHParser/ebnf.py

@@ -33,7 +33,8 @@ from DHParser.toolkit import load_if_file, escape_re, md5, sane_parser_name
 from DHParser.parser import Grammar, mixin_comment, nil_preprocessor, Forward, RE, NegativeLookahead, \
     Alternative, Series, Option, Required, OneOrMore, ZeroOrMore, Token, Compiler, \
     PreprocessorFunc
-from DHParser.syntaxtree import WHITESPACE_PTYPE, TOKEN_PTYPE, Node, TransformationFunc
+from DHParser.syntaxtree import Node, TransformationFunc
+from DHParser.base import WHITESPACE_PTYPE, TOKEN_PTYPE, Error
 from DHParser.transform import TransformationDict, traverse, remove_brackets, \
     reduce_single_child, replace_by_single_child, remove_expendables, \
     remove_tokens, flatten, forbid, assert_content, remove_infix_operator
@@ -397,8 +398,7 @@ class EBNFCompiler(Compiler):
                            'literalws': ['right'],
                            'tokens': set(),  # alt. 'preprocessor_tokens'
                            'filter': dict(),  # alt. 'filter'
-                           'ignorecase': False,
-                           'testing': False}
+                           'ignorecase': False}
 
     @property
     def result(self) -> str:
@@ -544,22 +544,18 @@ class EBNFCompiler(Compiler):
 
         # check for unconnected rules
 
-        if not self.directives['testing']:
-            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_symbol)
-            for leftover in defined_symbols:
-                self.rules[leftover][0].add_error(('Rule "%s" is not connected to parser '
-                                                   'root "%s" !') % (leftover,
-                                                                     self.root_symbol) + ' (Use directive "@testing=True" '
-                    'to supress this error message.)')
-                # root_node.error_flag = True
+        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_symbol)
+        for leftover in defined_symbols:
+            self.rules[leftover][0].add_error(('Rule "%s" is not connected to '
+                'parser root "%s" !') % (leftover, self.root_symbol), Error.WARNING)
 
         # set root_symbol parser and assemble python grammar definition
 
@@ -587,7 +583,7 @@ class EBNFCompiler(Compiler):
             else:
                 assert nd.parser.name == "directive", nd.as_sxpr()
                 self.compile(nd)
-                node.error_flag = node.error_flag or nd.error_flag
+                node.error_flag = max(node.error_flag, nd.error_flag)
         self.definitions.update(definitions)
 
         return self.assemble_parser(definitions, node)
@@ -679,9 +675,9 @@ class EBNFCompiler(Compiler):
             if value:
                 self.re_flags.add('i')
 
-        elif key == 'testing':
-            value = str(node.children[1])
-            self.directives['testing'] = value.lower() not in {"off", "false", "no"}
+        # elif key == 'testing':
+        #     value = str(node.children[1])
+        #     self.directives['testing'] = value.lower() not in {"off", "false", "no"}
 
         elif key == 'literalws':
             value = {item.lower() for item in self.compile(node.children[1])}

DHParser/parser.py

@@ -75,10 +75,10 @@ except ImportError:
     from .typing34 import Any, Callable, cast, Dict, Iterator, List, Set, Tuple, Union, Optional
 
 from DHParser.toolkit import is_logging, log_dir, logfile_basename, escape_re, sane_parser_name
-from DHParser.syntaxtree import WHITESPACE_PTYPE, TOKEN_PTYPE, ZOMBIE_PARSER, ParserBase, \
-    Node, TransformationFunc
-from DHParser.toolkit import StringView, EMPTY_STRING_VIEW, sv_match, sv_index, sv_search, \
-    load_if_file, error_messages, line_col
+from DHParser.syntaxtree import Node, TransformationFunc
+from DHParser.base import ParserBase, WHITESPACE_PTYPE, TOKEN_PTYPE, ZOMBIE_PARSER, Error, is_error, has_errors, \
+    StringView, EMPTY_STRING_VIEW
+from DHParser.toolkit import load_if_file, error_messages, line_col
 
 __all__ = ('PreprocessorFunc',
            'HistoryRecord',
@@ -161,15 +161,17 @@ class HistoryRecord:
         self.call_stack = [p for p in call_stack if p.ptype != ":Forward"]  # type: List['Parser']
         self.node = node                # type: Node
         self.remaining = remaining      # type: int
-        document = call_stack[-1].grammar.document__.text if call_stack else ''
-        self.line_col = line_col(document, len(document) - remaining)  # type: Tuple[int, int]
+        self.line_col = (1, 1)          # type: Tuple[int, int]
+        if call_stack:
+            document = call_stack[-1].grammar.document__.text
+            self.line_col = line_col(document, len(document) - remaining)
 
     def __str__(self):
         return 'line %i, column %i:  %s  "%s"' % \
                (self.line_col[0], self.line_col[1], self.stack, str(self.node))
 
     def err_msg(self) -> str:
-        return self.ERROR + ": " + "; ".join(self.node._errors).replace('\n', '\\')
+        return self.ERROR + ": " + "; ".join(str(e) for e in self.node._errors).replace('\n', '\\')
 
     @property
     def stack(self) -> str:
@@ -179,7 +181,7 @@ class HistoryRecord:
     @property
     def status(self) -> str:
         return self.FAIL if self.node is None else \
-            self.err_msg() if self.node._errors else self.MATCH
+            self.err_msg() if has_errors(self.node._errors) else self.MATCH
 
     @property
     def extent(self) -> slice:
@@ -276,7 +278,7 @@ def add_parser_guard(parser_func):