example.vodsl

/*
 *  created on 25 Feb 2022 
 */
 
 model example (0.1) "An example data model showing the constructs available" 
   author "Paul Harrison"
   author "An Other"
   
   include "IVOA-v1.0.vodsl"
   
package p "top level package" {
	package n "nested package" {
     primitive angle "another primitive"     
	}
}
   
enum options "an enum" {
	val1 "first option",
	val2 "second option"
}   

dtype aQuant -> ivoa:Quantity "an angle quantity" {
			value : p.n.angle  "angle";
}

abstract otype base {
		    q : ivoa:Quantity "a quantity";   
}

abstract otype ad1 -> base "an abstract subtype "{	
}

otype o1 {
	     /* the following attribute is a 'natural key' for the otype */
	       name : ivoa:string iskey "the identifier";
			   bv : ivoa:anyURI  "Description";
		    /* note use of ^ to be able to 
		            re-use reserved word.*/	
		    ^author: ivoa:string "author"; 
}

dtype myQuant -> ivoa:RealQuantity "a flagged quantity" {
			flag : ivoa:boolean "the flag" ;
}

/* it should be noted in this example that
 * @* and @+ are not "recommended" for attributes - it 
   might be better to use composition of otypes - but this is 
   not always the case */
otype multiplicities "the @ sign introduces a multiplicity"
{
	m1 : ivoa:integer @? "0 or 1";
	m2 : ivoa:integer @* "0 or many";
	m3 : ivoa:integer @+ "1 or many";
	m4 : ivoa:integer @[2] "twice (as an array?)";
}

 /*  this referred to otype is not affected by the lifecycle
   of other instances in the model */
 otype ReferedTo { 
 	test1: ivoa:integer "";
 }

/* instances of this contained class will only live
   as long as the containing instance.  */
otype Contained  {
 	test2: ivoa:string "";
 }
 
/* this example references and contains the above types */
otype RCTest { 
	ref references ReferedTo "";
	contained : Contained @+ as composition "";
}

/* an example of subsetting */
otype subs -> base {
	/* note that the requirement to refer to the q attribute of base */
   subset base.q as myQuant; //the type of base.q is a supertype of myQuant
}

/* an example of the syntax for a constraint */
otype constrained {
			val : ivoa:integer "just using a natural language constraint" 
			  < "greater than 5" as Natural> ;
		}