modifying rlcompleter to support completion through list lookups, updating license information as well

1 files changed, 197 insertions, 0 deletions

diff --git a/python/bncompleter.py b/python/bncompleter.py
new file mode 100644
index 00000000..b80cabca
--- /dev/null
+++ b/python/bncompleter.py
@@ -0,0 +1,197 @@
+""" This file is a modified version of rlcompleter.py from the Python
+project under the Python Software Foundation License 2:
+https://github.com/python/cpython/blob/master/Lib/rlcompleter.py
+https://github.com/python/cpython/blob/master/LICENSE
+
+The only changes made were to modify the regular expression in attr_matches
+and all code that relied on GNU readline (the later more for readability as
+it wasn't required).
+--------------
+Word completion for GNU readline.
+
+The completer completes keywords, built-ins and globals in a selectable
+namespace (which defaults to __main__); when completing NAME.NAME..., it
+evaluates (!) the expression up to the last dot and completes its attributes.
+
+It's very cool to do "import sys" type "sys.", hit the completion key (twice),
+and see the list of names defined by the sys module!
+
+Tip: to use the tab key as the completion key, call
+
+	readline.parse_and_bind("tab: complete")
+
+Notes:
+
+- Exceptions raised by the completer function are *ignored* (and generally cause
+  the completion to fail).  This is a feature -- since readline sets the tty
+  device in raw (or cbreak) mode, printing a traceback wouldn't work well
+  without some complicated hoopla to save, reset and restore the tty state.
+
+- The evaluation of the NAME.NAME... form may cause arbitrary application
+  defined code to be executed if an object with a __getattr__ hook is found.
+  Since it is the responsibility of the application (or the user) to enable this
+  feature, I consider this an acceptable risk.  More complicated expressions
+  (e.g. function calls or indexing operations) are *not* evaluated.
+
+- When the original stdin is not a tty device, GNU readline is never
+  used, and this module (and the readline module) are silently inactive.
+
+"""
+
+import atexit
+import builtins
+import __main__
+
+__all__ = ["Completer"]
+
+class Completer:
+	def __init__(self, namespace = None):
+		"""Create a new completer for the command line.
+
+		Completer([namespace]) -> completer instance.
+
+		If unspecified, the default namespace where completions are performed
+		is __main__ (technically, __main__.__dict__). Namespaces should be
+		given as dictionaries.
+
+		Completer instances should be used as the completion mechanism of
+		readline via the set_completer() call:
+
+		readline.set_completer(Completer(my_namespace).complete)
+		"""
+
+		if namespace and not isinstance(namespace, dict):
+			raise TypeError('namespace must be a dictionary')
+
+		# Don't bind to namespace quite yet, but flag whether the user wants a
+		# specific namespace or to use __main__.__dict__. This will allow us
+		# to bind to __main__.__dict__ at completion time, not now.
+		if namespace is None:
+			self.use_main_ns = 1
+		else:
+			self.use_main_ns = 0
+			self.namespace = namespace
+
+	def complete(self, text, state):
+		"""Return the next possible completion for 'text'.
+
+		This is called successively with state == 0, 1, 2, ... until it
+		returns None.  The completion should begin with 'text'.
+
+		"""
+		if self.use_main_ns:
+			self.namespace = __main__.__dict__
+
+		if not text.strip():
+			if state == 0:
+				return '\t'
+			else:
+				return None
+
+		if state == 0:
+			if "." in text:
+				self.matches = self.attr_matches(text)
+			else:
+				self.matches = self.global_matches(text)
+		try:
+			return self.matches[state]
+		except IndexError:
+			return None
+
+	def _callable_postfix(self, val, word):
+		if callable(val):
+			word = word + "("
+		return word
+
+	def global_matches(self, text):
+		"""Compute matches when text is a simple name.
+
+		Return a list of all keywords, built-in functions and names currently
+		defined in self.namespace that match.
+
+		"""
+		import keyword
+		matches = []
+		seen = {"__builtins__"}
+		n = len(text)
+		for word in keyword.kwlist:
+			if word[:n] == text:
+				seen.add(word)
+				if word in {'finally', 'try'}:
+					word = word + ':'
+				elif word not in {'False', 'None', 'True',
+								  'break', 'continue', 'pass',
+								  'else'}:
+					word = word + ' '
+				matches.append(word)
+		for nspace in [self.namespace, builtins.__dict__]:
+			for word, val in nspace.items():
+				if word[:n] == text and word not in seen:
+					seen.add(word)
+					matches.append(self._callable_postfix(val, word))
+		return matches
+
+	def attr_matches(self, text):
+		"""Compute matches when text contains a dot.
+
+		Assuming the text is of the form NAME.NAME....[NAME], and is
+		evaluable in self.namespace, it will be evaluated and its attributes
+		(as revealed by dir()) are used as possible completions.  (For class
+		instances, class members are also considered.)
+
+		WARNING: this can still invoke arbitrary C code, if an object
+		with a __getattr__ hook is evaluated.
+
+		"""
+		import re
+		m = re.match(r"([\w\[\]]+(\.[\w\[\]]+)*)\.(\w*)", text)
+		if not m:
+			return []
+		expr, attr = m.group(1, 3)
+		try:
+			thisobject = eval(expr, self.namespace)
+		except Exception:
+			return []
+
+		# get the content of the object, except __builtins__
+		words = set(dir(thisobject))
+		words.discard("__builtins__")
+
+		if hasattr(thisobject, '__class__'):
+			words.add('__class__')
+			words.update(get_class_members(thisobject.__class__))
+		matches = []
+		n = len(attr)
+		if attr == '':
+			noprefix = '_'
+		elif attr == '_':
+			noprefix = '__'
+		else:
+			noprefix = None
+		while True:
+			for word in words:
+				if (word[:n] == attr and
+					not (noprefix and word[:n+1] == noprefix)):
+					match = "%s.%s" % (expr, word)
+					try:
+						val = getattr(thisobject, word)
+					except Exception:
+						pass  # Include even if attribute not set
+					else:
+						match = self._callable_postfix(val, match)
+					matches.append(match)
+			if matches or not noprefix:
+				break
+			if noprefix == '_':
+				noprefix = '__'
+			else:
+				noprefix = None
+		matches.sort()
+		return matches
+
+def get_class_members(klass):
+	ret = dir(klass)
+	if hasattr(klass,'__bases__'):
+		for base in klass.__bases__:
+			ret = ret + get_class_members(base)
+	return ret
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