Re: grXML grammar question

• From: Lutz Birkhahn <lbirkhahn@adomo.com>
• Date: Fri, 25 Oct 2002 19:11:25 -0700
• To: "Yahn Teisseire" <yahn@ukibi.com>, <www-voice@w3.org>
• Message-Id: <02102519112505.01279@leia>

Yahn Teisseire wrote:
> I'd like a grammar able to return 3 spelled letters to my application
> like:
>
>    <grammar root="command">
>         <rule id="command" scope="public">
>             <item>
>              <ruleref uri="#firstletter"/>
>              <ruleref uri="#secondletter"/>
>              <ruleref uri="#thirdletter"/>
>             </item>
>         </rule>
>
>         <rule id="firstletter">
>              <item><ruleref
> uri="#alphabet"/><tag>firstletter=$alphabet</tag></item> </rule>
>
>         <rule id="secondletter">
>              <item><ruleref
> uri="#alphabet"/><tag>secondletter=$alphabet</tag></item> </rule>
>
>         <rule id="thirdletter">
>              <item><ruleref
> uri="#alphabet"/><tag>thirdletter=$alphabet</tag></item> </rule>

Looks almost good to me. You most likely want to look at
http://www.w3.org/TR/semantic-interpretation/ (SISR). If we're talking
about a real VXML interpreter, then of course your interpreter's docu-
mentation is more important.

I think you have to copy the subrule's tags to the root rule, i.e.
the root rule would look like

    <rule id="command" scope="public">
      <item>
        <ruleref uri="#firstletter"/>
        <ruleref uri="#secondletter"/>
        <ruleref uri="#thirdletter"/>
        <tag>
          firstletter  = $firstletter.firstletter;
          secondletter = $secondletter.secondletter;
          thirdletter  = $thirdletter.thirdletter;
        </tag>
      </item>
    </rule>

I would probably simplify it to:

    <rule id="command" scope="public">
      <item>
        <ruleref uri="#firstletter"/>
        <ruleref uri="#secondletter"/>
        <ruleref uri="#thirdletter"/>
        <tag>
          $ = $firstletter + $secondletter + $thirdletter;
        </tag>
      </item>
    </rule>

    <rule id="firstletter">
      <item><ruleref uri="#alphabet"/><tag>$alphabet</tag></item>
    </rule>

    <rule id="secondletter">
      <item><ruleref uri="#alphabet"/><tag>$alphabet</tag></item>
    </rule>

    <rule id="thirdletter">
      <item><ruleref uri="#alphabet"/><tag>$alphabet</tag></item>
    </rule>

Or even simpler (not sure if this still works):

   <rule id="command" scope="public">
      <tag> $ = "" </tag>
      <item repeat="3">
        <ruleref uri="#alphabet"/>
        <tag> $ = $ + $alphabet </tag>
      </item>
    </rule>

Or return it as list (this is equivalent to the "tops" rule in the sec-
tion 8 example of SISR):

   <rule id="command" scope="public">
      <ruleref uri="#alphabet"/>
      <tag> Append([], $alphabet) </tag>
      <item repeat="2">
        <ruleref uri="#alphabet"/>
        <tag> Append($, $alphabet) </tag>
      </item>
    </rule>

Have fun,

/lutz

-- 
Lutz Birkhahn                                       System Software Engineer
Adomo Inc. --  10001 N. De Anza Boulevard Suite 220  --  Cupertino, CA 95014
phone: +1 (408) 996-7086 ext. 118                 private: +1 (408) 564-0162

Received on Friday, 25 October 2002 22:11:27 UTC