# L-27 MCS 260 Mon 29 Oct 2007 : useassert.py
#
#
def searchlist ( L , i ):
   """
   Searches a list L for the integer i,
   returning -1 if the item does not belong
   to the list, or else returning the position
   of the item in the list.

   Preconditions:
      isinstance(L,list) and isinstance(i,int)

   Postconditions:
      searchlist(L,i) == -1 or
      searchlist(L,i) == p and L[p] == i
   """

   assert isinstance(L,list)
   assert isinstance(i,int)
   p = -1
   for k in range(0,len(L)):
      if L[k] == i:
         p = k
         break
   assert p == -1 or (p == k and L[k] == i)
   return p