# piglatin.py
# Walker M. White (wmw2)
# September 4, 2013
"""Module for converting English words to Pig Latin

This module contains two functions: first_vowel and pigify. The first
is a helper function of the second (which is the primary function).
You are to implement the second function. While you are encouraged to
test your answer, you do not need to write a unit test.  Simply
write down some possible test cases, and show those test cases to
your instructor to get credit"""

def first_vowel(w):
    """Returns: position of the first vowel; -1 if no vowels.
    
    There is a better way to do this function with for-loops, 
    but we have not covered that topic yet.
    
    Precondition: w is a nonempty string with only lowercase letters"""
    minpos = len(w) # invalid position; currently no vowels found
    
    # search for a
    pos = w.find('a')
    if pos != -1 and pos < minpos: # a found and is closest
        minpos = pos
    
    # search for e
    pos = w.find('e')
    if pos != -1 and pos < minpos: # e found and is closest
        minpos = pos
    
    # search for i
    pos = w.find('i')
    if pos != -1 and pos < minpos: # i found and is closest
        minpos = pos
    
    # search for o
    pos = w.find('o')
    if pos != -1 and pos < minpos: # o found and is closest
        minpos = pos
    
    # search for u
    pos = w.find('u')
    if pos != -1 and pos < minpos: # u found and is closest
        minpos = pos
    
    # search for y not at front
    backpos = w[1:].find('y')
    if backpos != -1: # y found in "back part"
        pos = backpos + 1; # position of y in w
        if pos < minpos: # y found in w and is closest
            minpos = pos
    
    # found something if minpos moved from first assignment
    return minpos if minpos != len(w) else -1


def pigify(w):
    """Returns: copy of w converted to Pig Latin
    
    See the lab handout for the complete rules on Pig Latin.
    
    Precondition: w is a nonempty string with only lowercase letters"""
    # ENFORCE THE PRECONDITION
    return '' # STUB. Implement me