diff options
Diffstat (limited to 'pyparsing/core.py')
| -rw-r--r-- | pyparsing/core.py | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/pyparsing/core.py b/pyparsing/core.py index 1866fc2..0b0b2c8 100644 --- a/pyparsing/core.py +++ b/pyparsing/core.py @@ -1,6 +1,7 @@ # # core.py # +from collections import deque import os import typing from typing import ( @@ -488,6 +489,23 @@ class ParserElement(ABC): self.suppress_warnings_.append(warning_type) return self + def visit_all(self): + """General-purpose method to yield all expressions and sub-expressions + in a grammar. Typically just for internal use. + """ + to_visit = deque([self]) + seen = set() + while to_visit: + cur = to_visit.popleft() + + # guard against looping forever through recursive grammars + if cur in seen: + continue + seen.add(cur) + + to_visit.extend(cur.recurse()) + yield cur + def copy(self) -> "ParserElement": """ Make a copy of this :class:`ParserElement`. Useful for defining @@ -1751,10 +1769,11 @@ class ParserElement(ABC): self.debug = True return self - def set_debug(self, flag: bool = True) -> "ParserElement": + def set_debug(self, flag: bool = True, recurse: bool = False) -> "ParserElement": """ Enable display of debugging messages while doing pattern matching. Set ``flag`` to ``True`` to enable, ``False`` to disable. + Set ``recurse`` to ``True`` to set the debug flag on this expression and all sub-expressions. Example:: @@ -1788,6 +1807,11 @@ class ParserElement(ABC): which makes debugging and exception messages easier to understand - for instance, the default name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``. """ + if recurse: + for expr in self.visit_all(): + expr.set_debug(flag, recurse=False) + return self + if flag: self.set_debug_actions( _default_start_debug_action, |