"""
CS61A Summer 2012
Skeleton code, intended for use in Lab 5. Uses IDicts instead of
the built-in dict.
"""
from idict import idict_select, idict_insert

def build_successors_table(tokens):
    """Return a dictionary: keys are words; values are tuples of 
successors."""
    table = make_idict()
    prev = '.'
    for word in tokens:
        if idict_select(table, prev):
            "**FILL THIS IN**"

        else:
            "**FILL THIS IN**"

        prev = word
    return table

def construct_sent(word, table):
    """Prints a random sentence starting with word, sampling from table"""
    import random
    result = ' '
    while word not in ('.', '!', '?'):
        "** FILL THIS IN**"

    return result + word

def shakespeare_tokens(path = 'shakespeare.txt', url = 'http://inst.eecs.berkeley.edu/~cs61a/fa11/shakespeare.txt'):
    """Return the words of Shakespeare's plays as a list"""
    import os
    from urllib.request import urlopen
    if os.path.exists(path):
        return open('shakespeare.txt', encoding='ascii').read().split()
    else:
        shakespeare = urlopen(url)
        # Return first 2000 words, to avoid bringing IDicts to its
        # knees (originally returned ~900,000 words!)
        return shakespeare.read().decode(encoding='ascii').split()[:2000]