/*
 *  call-seq:
 *     hsh.delete(key)                   => value
 *     hsh.delete(key) {| key | block }  => value
 *  
 *  Deletes and returns a key-value pair from <i>hsh</i> whose key is
 *  equal to <i>key</i>. If the key is not found, returns the
 *  <em>default value</em>. If the optional code block is given and the
 *  key is not found, pass in the key and return the result of
 *  <i>block</i>.
 *     
 *     h = { "a" => 100, "b" => 200 }
 *     h.delete("a")                              #=> 100
 *     h.delete("z")                              #=> nil
 *     h.delete("z") { |el| "#{el} not found" }   #=> "z not found"
 *     
 */

VALUE
rb_hash_delete(hash, key)
    VALUE hash, key;
{
    VALUE val;

    rb_hash_modify(hash);
    if (RHASH(hash)->iter_lev > 0) {
        if (st_delete_safe(RHASH(hash)->tbl, (st_data_t*)&key, &val, Qundef)) {
            FL_SET(hash, HASH_DELETED);
            return val;
        }
    }
    else if (st_delete(RHASH(hash)->tbl, (st_data_t*)&key, &val))
        return val;
    if (rb_block_given_p()) {
        return rb_yield(key);
    }
    return Qnil;
}