Examples of client.net.sf.saxon.ce.value.SingletonClosure

client.net.sf.saxon.ce.value.SingletonClosure

A SingletonClosure represents a value that has not yet been evaluated: the value is represented by an expression, together with saved values of all the context variables that the expression depends on. The value of a SingletonClosure is always either a single item or an empty sequence.

The expression may depend on local variables and on the context item; these values are held in the saved XPathContext object that is kept as part of the Closure, and they will always be read from that object. The expression may also depend on global variables; these are unchanging, so they can be read from the Bindery in the normal way. Expressions that depend on other contextual information, for example the values of position(), last(), current(), current-group(), should not be evaluated using this mechanism: they should always be evaluated eagerly. This means that the Closure does not need to keep a copy of these context variables.

            b.setNotExecuting(this);
            if (err instanceof XPathException.Circularity) {
                err.setErrorCode("XTDE0640");
                err.setXPathContext(context);
                // Detect it more quickly the next time (in a pattern, the error is recoverable)
                SingletonClosure closure = new SingletonClosure(new ErrorExpression(err), context);
                b.defineGlobalVariable(this, closure);
                err.setLocator(getSourceLocator());
                throw err;
            } else {
                throw err;

Examples of client.net.sf.saxon.ce.value.SingletonClosure

Related Classes of client.net.sf.saxon.ce.value.SingletonClosure