var sparqler = new SPARQL.Service("http://sparql.org/sparql");

// graphs and prefixes defined here
// are inherited by all future queries
sparqler.addDefaultGraph("http://thefigtrees.net/lee/ldf-card");
sparqler.addNamedGraph("http://torrez.us/elias/foaf.rdf");
sparqler.setPrefix("foaf", "http://xmlns.com/foaf/0.1/"); 
sparqler.setPrefix("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
	
// "json" is the default output format
sparqler.setOutput("json");

var query = sparqler.createQuery();

// these settings are for this query only
query.addDefaultGraph(...);
query.addNamedGraph(...);
query.setPrefix(...);

// query wrappers:

// passes standard JSON results object to success callback
query.setPrefix("ldf", "http://thefigtrees.net/lee/ldf-card#");
query.query(
    "SELECT ?who ?mbox WHERE { ldf:LDF foaf:knows ?who . ?who foaf:mbox ?mbox }",
    {failure: onFailure, success: function(json) { for (var x in json.head.vars) { ... } ...}}
);

// passes boolean value to success callback
query.ask(
    "ASK ?person WHERE { ?person foaf:knows [ foaf:name "Dan Connolly" ] }",
    {failure: onFailure, success: function(bool) { if (bool) ... }}
); 

// passes a single vector (array) of values 
// representing a single column of results 
// to success callback
query.setPrefix("ldf", "http://thefigtrees.net/lee/ldf-card#");
var addresses = query.selectValues(
    "SELECT ?mbox WHERE { _:someone foaf:mbox ?mbox }",
    {failure: onFailure, success: function(values) { for (var i = 0; i < values.length; i++) { ... values[i] ...} } }
); 

// passes a single value representing a single 
// row of a single column (variable) to success callback
query.setPrefix("ldf", "http://thefigtrees.net/lee/ldf-card#");
var myAddress = query.selectSingleValue(
    "SELECT ?mbox WHERE {ldf:LDF foaf:mbox ?mbox }",
    {failure: onFailure, success: function(value) { alert("value is: " + value); } }
); 
	
// shortcuts for all of the above 
// (w/o ability to set any query-specific graphs or prefixes)
sparqler.query(...);
sparqler.ask(...);
sparqler.selectValues(...);
sparqler.selectSingleValue(...);