OPTIONAL
SYNOPSIS
        mixed* insert_alist (mixed key, mixed data..., mixed * alist)
        int    insert_alist (mixed key, mixed * keys)

DESCRIPTION
        1. Form: Alist Insertion

          The <key> and all following <data> values are inserted
          into the <alist>. If an entry for <key> already exists
          in the list, just the data values are replaced. The number
          of <data> values must match the number of data arrays
          in the alist, naturally.

          Result is the updated <alist>.

        2. Form: Key Insertion

          Insert the <key> into the (ordered) array of <keys>, so that
          subsequent assoc()s can perform quick lookups. Result is the
          index at which <key> was inserted (or already found).

          CAVEAT: when working with string keys, the index might no longer
            be valid after the next call to insert_alist().

        Complexity: O(lg(n) + a*n) where n is the number of keys and
        s is a very small constant (for block move);

SEE ALSO
        alists(LPC), assoc(E), order_alist(E)