Use of Tags

Jonathan Borden jborden at mediaone.net
Wed Apr 21 19:03:58 BST 1999


Andrew:

>Jonathan Borden asks what "local scope" means.  Consider the example
>
><Book>
>    <title>The Virgin Queen</title>
>    <subject>Queen Elizabeth</subject>
></Book>
>
><Person>
>    <title>Queen</title>
>    <subject>Raleigh</subject>
></Person>
>
>The elements "title" and "subject" have different meaning in the two cases.
>When the meaning, definition, etc. of a name is determined by its
enclosure,
>that is, when the thing the name denotes is determined by its enclosure,
>that is "local scope".
>
>
    Ok fine, then my question stands: Isn't the dt:dt attribute a perfectly
good way to distinguish value types *despite* local scope intentions e.g.

<Book>
    <title>The Virgin Queen</title>
    <subject>Queen Elizabeth</subject>
    <value dt:dt="float">12.95</value>
</Book>

<Person>
    <title>Queen</title>
    <subject>Raleigh</subject>
    <value dt:dt="string">historical</value>
</Person>
>

    And if this objection to the use of elements is sufficiently handled in
this fashion, are there other pressing reasons why values (particularly
table columns) ought be expressed as attributes rather than elements? To me
the most pressing reason to use elements to encode "recordsets" is that in
the absense of a schema decl or DTD, the content can be correctly
interpreted. For example when converting to and from SQL, "int" values
though textualy represented are not 'quoted' while character values are
e.g.: UPDATE table SET intval = 3, charval='3' or
    SELECT FROM table WHERE intval = 3 OR charval = '3'


Jonathan Borden
http://jabr.ne.mediaone.net



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