* simpler var commands. Currently two expressions are targetted for expansion: string
* concatenation and escaping functions.
*/
private PCommand optimizeVarCommands(AVarCommand varCommand) {
PExpression expression = varCommand.getExpression();
PPosition position = varCommand.getPosition();
// This test relies on the type optimizer having replaced add commands
// with numeric add commands.
if (expression instanceof AAddExpression) {
// Replace: <?cs var:a + b ?>