calc.dtd

该计算器既有经典的GUI按钮模式

<?xml version='1.0' encoding='us-ascii'?>

<!--
    DTD for a simple "calc functions".
-->
<!ELEMENT calc (class*)>
<!ELEMENT class (function*)>
<!ATTLIST class 
            name    CDATA    #REQUIRED
            auto   (false | true ) "false"
            match   CDATA "*"
>
<!ELEMENT function (alias*)>
<!ATTLIST function 
            name    CDATA    #IMPLIED
            method  CDATA    #REQUIRED
>
<!ELEMENT alias (#PCDATA)>