    /*
     * call-seq:
     *  read_memory(string)
     *
     * Create a new Schema from the contents of +string+
     */
    static VALUE read_memory(VALUE klass, VALUE content)
    {

      xmlSchemaParserCtxtPtr ctx = xmlSchemaNewMemParserCtxt(
          (const char *)StringValuePtr(content),
          RSTRING_LEN(content)
      );

      VALUE errors = rb_ary_new();
      xmlSetStructuredErrorFunc((void *)errors, Nokogiri_error_array_pusher);

    #ifdef HAVE_XMLSCHEMASETPARSERSTRUCTUREDERRORS
      xmlSchemaSetParserStructuredErrors(
        ctx,
        Nokogiri_error_array_pusher,
        (void *)errors
      );
    #endif

      xmlSchemaPtr schema = xmlSchemaParse(ctx);

      xmlSetStructuredErrorFunc(NULL, NULL);
      xmlSchemaFreeParserCtxt(ctx);

      if(NULL == schema) {
        xmlErrorPtr error = xmlGetLastError();
        if(error)
          Nokogiri_error_raise(NULL, error);
        else
          rb_raise(rb_eRuntimeError, "Could not parse document");

        return Qnil;
      }

      VALUE rb_schema = Data_Wrap_Struct(klass, 0, dealloc, schema);
      rb_iv_set(rb_schema, "@errors", errors);

      return rb_schema;
    }