def __init__(self, rules='', **more_rules):
"""Construct a grammar.
:arg rules: A string of production rules, one per line.
:arg default_rule: The name of the rule invoked when you call
:meth:`parse()` or :meth:`match()` on the grammar. Defaults to the
first rule. Falls back to None if there are no string-based rules
in this grammar.
:arg more_rules: Additional kwargs whose names are rule names and
values are Expressions or custom-coded callables which accomplish
things the built-in rule syntax cannot. These take precedence over
``rules`` in case of naming conflicts.
"""
decorated_custom_rules = dict(
(k, expression(v, k, self) if isfunction(v) or ismethod(v) else v)
for k, v in iteritems(more_rules))
self._expressions, first = self._expressions_from_rules(
rules, decorated_custom_rules)
self.default_rule = first # may be None
def __init__(self, rules='', **more_rules):
"""Construct a grammar.
:arg rules: A string of production rules, one per line.
:arg default_rule: The name of the rule invoked when you call
:meth:`parse()` or :meth:`match()` on the grammar. Defaults to the
first rule. Falls back to None if there are no string-based rules
in this grammar.
:arg more_rules: Additional kwargs whose names are rule names and
values are Expressions or custom-coded callables which accomplish
things the built-in rule syntax cannot. These take precedence over
``rules`` in case of naming conflicts.
"""
decorated_custom_rules = dict(
(k, expression(v, k, self) if isfunction(v) or
ismethod(v) else
v) for k, v in iteritems(more_rules))
self._expressions, first = self._expressions_from_rules(rules, decorated_custom_rules)
self.default_rule = first # may be None
def __init__(self, rules='', default_rule=None, **custom_rules):
"""Construct a grammar.
:arg rules: A string of production rules, one per line.
:arg default_rule: The name of the rule invoked when you call
:meth:`parse()` or :meth:`match()` on the grammar. Defaults to the
first rule. Falls back to None if there are no string-based rules
in this grammar.
:arg custom_rules: Custom-coded rules: Expressions or plain callables
to accomplish things the built-in rule syntax cannot. These take
precedence over ``rules`` in case of naming conflicts.
"""
decorated_custom_rules = dict(
(k, expression(v, k, self) if isfunction(v) or
ismethod(v) else
v) for k, v in custom_rules.iteritems())
exprs, first = self._expressions_from_rules(rules, decorated_custom_rules)
self.update(exprs)
self.default_rule = exprs[default_rule] if default_rule else first
