(base_seq)
return decorator
Memo decorator for associated sequences defined by recurrence starting from base

    base_seq(n) -- callable to get base sequence elements

    XXX works only for Pn0 = base_seq(0) cases
    XXX works only for m <= n cases
Memo decorator for associated sequences defined by recurrence starting from base
Memo decorator for associated sequences defined by recurrence starting from base
def assoc_recurrence_memo(base_seq):
    """
    Memo decorator for associated sequences defined by recurrence starting from base

    base_seq(n) -- callable to get base sequence elements

    XXX works only for Pn0 = base_seq(0) cases
    XXX works only for m <= n cases
    """

    cache = []

    def decorator(f):
        @wraps(f)
        def g(n, m):
            L = len(cache)
            if n < L:
                return cache[n][m]

            for i in xrange(L, n + 1):
                # get base sequence
                F_i0 = base_seq(i)
                F_i_cache = [F_i0]
                cache.append(F_i_cache)

                # XXX only works for m <= n cases
                # generate assoc sequence
                for j in xrange(1, i + 1):
                    F_ij = f(i, j, cache)
                    F_i_cache.append(F_ij)

            return cache[n][m]

        return g
    return decorator
def assoc_recurrence_memo ( base_seq ) : cache = [ ] def decorator ( f ) : @ wraps ( f ) def g ( n , m ) : L = len ( cache ) if n < L : return cache [ n ] [ m ] for i in xrange ( L , n + 1 ) : # get base sequence F_i0 = base_seq ( i ) F_i_cache = [ F_i0 ] cache . append ( F_i_cache ) # XXX only works for m <= n cases # generate assoc sequence for j in xrange ( 1 , i + 1 ) : F_ij = f ( i , j , cache ) F_i_cache . append ( F_ij ) return cache [ n ] [ m ] return g return decorator