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Diffstat (limited to 'src/pip/_vendor/pyparsing/exceptions.py')
| -rw-r--r-- | src/pip/_vendor/pyparsing/exceptions.py | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/src/pip/_vendor/pyparsing/exceptions.py b/src/pip/_vendor/pyparsing/exceptions.py new file mode 100644 index 000000000..a38447bb0 --- /dev/null +++ b/src/pip/_vendor/pyparsing/exceptions.py @@ -0,0 +1,267 @@ +# exceptions.py + +import re +import sys +import typing + +from .util import col, line, lineno, _collapse_string_to_ranges +from .unicode import pyparsing_unicode as ppu + + +class ExceptionWordUnicode(ppu.Latin1, ppu.LatinA, ppu.LatinB, ppu.Greek, ppu.Cyrillic): + pass + + +_extract_alphanums = _collapse_string_to_ranges(ExceptionWordUnicode.alphanums) +_exception_word_extractor = re.compile("([" + _extract_alphanums + "]{1,16})|.") + + +class ParseBaseException(Exception): + """base exception class for all parsing runtime exceptions""" + + # Performance tuning: we construct a *lot* of these, so keep this + # constructor as small and fast as possible + def __init__( + self, + pstr: str, + loc: int = 0, + msg: typing.Optional[str] = None, + elem=None, + ): + self.loc = loc + if msg is None: + self.msg = pstr + self.pstr = "" + else: + self.msg = msg + self.pstr = pstr + self.parser_element = self.parserElement = elem + self.args = (pstr, loc, msg) + + @staticmethod + def explain_exception(exc, depth=16): + """ + Method to take an exception and translate the Python internal traceback into a list + of the pyparsing expressions that caused the exception to be raised. + + Parameters: + + - exc - exception raised during parsing (need not be a ParseException, in support + of Python exceptions that might be raised in a parse action) + - depth (default=16) - number of levels back in the stack trace to list expression + and function names; if None, the full stack trace names will be listed; if 0, only + the failing input line, marker, and exception string will be shown + + Returns a multi-line string listing the ParserElements and/or function names in the + exception's stack trace. + """ + import inspect + from .core import ParserElement + + if depth is None: + depth = sys.getrecursionlimit() + ret = [] + if isinstance(exc, ParseBaseException): + ret.append(exc.line) + ret.append(" " * (exc.column - 1) + "^") + ret.append("{}: {}".format(type(exc).__name__, exc)) + + if depth > 0: + callers = inspect.getinnerframes(exc.__traceback__, context=depth) + seen = set() + for i, ff in enumerate(callers[-depth:]): + frm = ff[0] + + f_self = frm.f_locals.get("self", None) + if isinstance(f_self, ParserElement): + if frm.f_code.co_name not in ("parseImpl", "_parseNoCache"): + continue + if id(f_self) in seen: + continue + seen.add(id(f_self)) + + self_type = type(f_self) + ret.append( + "{}.{} - {}".format( + self_type.__module__, self_type.__name__, f_self + ) + ) + + elif f_self is not None: + self_type = type(f_self) + ret.append("{}.{}".format(self_type.__module__, self_type.__name__)) + + else: + code = frm.f_code + if code.co_name in ("wrapper", "<module>"): + continue + + ret.append("{}".format(code.co_name)) + + depth -= 1 + if not depth: + break + + return "\n".join(ret) + + @classmethod + def _from_exception(cls, pe): + """ + internal factory method to simplify creating one type of ParseException + from another - avoids having __init__ signature conflicts among subclasses + """ + return cls(pe.pstr, pe.loc, pe.msg, pe.parserElement) + + @property + def line(self) -> str: + """ + Return the line of text where the exception occurred. + """ + return line(self.loc, self.pstr) + + @property + def lineno(self) -> int: + """ + Return the 1-based line number of text where the exception occurred. + """ + return lineno(self.loc, self.pstr) + + @property + def col(self) -> int: + """ + Return the 1-based column on the line of text where the exception occurred. + """ + return col(self.loc, self.pstr) + + @property + def column(self) -> int: + """ + Return the 1-based column on the line of text where the exception occurred. + """ + return col(self.loc, self.pstr) + + def __str__(self) -> str: + if self.pstr: + if self.loc >= len(self.pstr): + foundstr = ", found end of text" + else: + # pull out next word at error location + found_match = _exception_word_extractor.match(self.pstr, self.loc) + if found_match is not None: + found = found_match.group(0) + else: + found = self.pstr[self.loc : self.loc + 1] + foundstr = (", found %r" % found).replace(r"\\", "\\") + else: + foundstr = "" + return "{}{} (at char {}), (line:{}, col:{})".format( + self.msg, foundstr, self.loc, self.lineno, self.column + ) + + def __repr__(self): + return str(self) + + def mark_input_line(self, marker_string: str = None, *, markerString=">!<") -> str: + """ + Extracts the exception line from the input string, and marks + the location of the exception with a special symbol. + """ + markerString = marker_string if marker_string is not None else markerString + line_str = self.line + line_column = self.column - 1 + if markerString: + line_str = "".join( + (line_str[:line_column], markerString, line_str[line_column:]) + ) + return line_str.strip() + + def explain(self, depth=16) -> str: + """ + Method to translate the Python internal traceback into a list + of the pyparsing expressions that caused the exception to be raised. + + Parameters: + + - depth (default=16) - number of levels back in the stack trace to list expression + and function names; if None, the full stack trace names will be listed; if 0, only + the failing input line, marker, and exception string will be shown + + Returns a multi-line string listing the ParserElements and/or function names in the + exception's stack trace. + + Example:: + + expr = pp.Word(pp.nums) * 3 + try: + expr.parse_string("123 456 A789") + except pp.ParseException as pe: + print(pe.explain(depth=0)) + + prints:: + + 123 456 A789 + ^ + ParseException: Expected W:(0-9), found 'A' (at char 8), (line:1, col:9) + + Note: the diagnostic output will include string representations of the expressions + that failed to parse. These representations will be more helpful if you use `set_name` to + give identifiable names to your expressions. Otherwise they will use the default string + forms, which may be cryptic to read. + + Note: pyparsing's default truncation of exception tracebacks may also truncate the + stack of expressions that are displayed in the ``explain`` output. To get the full listing + of parser expressions, you may have to set ``ParserElement.verbose_stacktrace = True`` + """ + return self.explain_exception(self, depth) + + markInputline = mark_input_line + + +class ParseException(ParseBaseException): + """ + Exception thrown when a parse expression doesn't match the input string + + Example:: + + try: + Word(nums).set_name("integer").parse_string("ABC") + except ParseException as pe: + print(pe) + print("column: {}".format(pe.column)) + + prints:: + + Expected integer (at char 0), (line:1, col:1) + column: 1 + + """ + + +class ParseFatalException(ParseBaseException): + """ + User-throwable exception thrown when inconsistent parse content + is found; stops all parsing immediately + """ + + +class ParseSyntaxException(ParseFatalException): + """ + Just like :class:`ParseFatalException`, but thrown internally + when an :class:`ErrorStop<And._ErrorStop>` ('-' operator) indicates + that parsing is to stop immediately because an unbacktrackable + syntax error has been found. + """ + + +class RecursiveGrammarException(Exception): + """ + Exception thrown by :class:`ParserElement.validate` if the + grammar could be left-recursive; parser may need to enable + left recursion using :class:`ParserElement.enable_left_recursion<ParserElement.enable_left_recursion>` + """ + + def __init__(self, parseElementList): + self.parseElementTrace = parseElementList + + def __str__(self) -> str: + return "RecursiveGrammarException: {}".format(self.parseElementTrace) |