from __future__ import generators
import __builtin__

from keyword import kwlist

def completions(str, domains):
    longest_prefix = None
    r = []
    for list in domains:
        if not list is None:
            for e in list:
                print "trying: %s" % e
                if e.startswith(str) and not e in r:
                    r.append(e)
    return r

dir_ast = parser.expr("__builtin__.dir")
def complete_string(str, globals, locals):
    last_dot = str.rfind('.')
    if last_dot > 0:
        e = eval(str[:last_dot], globals, locals)
        c = completions(str[last_dot+1:], [ dir(e) ])
    else:
        c = completions(str, [ locals, globals, __builtin__, kwlist ] )
    print "%s completed to: %s" % (str, c)
    return c