def __init__(self, **kw):
"""
Abstract representation of parser
Keyword arguments:
- read - a callable accepting an int arg (nbytes) and returning a string,
default is this class' read() method
- file - a file object, or string of a pathname to open as a file, defaults
to sys.stdin. Note that you can leave this blank, and pass a file keyword
argument to the .run() method.
- verbose - set to 1 to enable verbose output messages, default 0
- keepfiles - if non-zero, keeps any files generated in the
course of building the parser engine; by default, all these
files get deleted upon a successful engine build
- defaultNodeClass - the class to use for creating parse nodes, default
is self.defaultNodeClass (in this base class, BisonNode)
"""
# setup
read = kw.get('read', None)
if read:
self.read = read
fileobj = kw.get('file', None)
if fileobj:
if isinstance(fileobj, str):
try:
fileobj = open(fileobj, 'rb')
except:
raise Exception('Cannot open input file %s' % fileobj)
self.file = fileobj
else:
self.file = sys.stdin
nodeClass = kw.get('defaultNodeClass', None)
if nodeClass:
self.defaultNodeClass = nodeClass
self.verbose = kw.get('verbose', 0)
if 'keepfiles' in kw:
self.keepfiles = kw['keepfiles']
# if engine lib name not declared, invent ont
if not self.bisonEngineLibName:
self.bisonEngineLibName = self.__class__.__module__ + '-parser'
# get an engine
self.engine = ParserEngine(self)
