/// <summary>To write out the value of a condition expr, invoke the evaluator in eval.g
/// to walk the condition tree computing the boolean value. If result
/// is true, then write subtemplate.
/// </summary>
public override int write(StringTemplate self, StringTemplateWriter outWriter)
{
if (exprTree == null || self == null || outWriter == null)
{
return 0;
}
// System.out.println("evaluating conditional tree: "+exprTree.toStringList());
ActionEvaluator eval = new ActionEvaluator(self, this, outWriter);
int n = 0;
try
{
// get conditional from tree and compute result
AST cond = exprTree.getFirstChild();
bool includeSubtemplate = eval.ifCondition(cond); // eval and write out tree
// System.out.println("subtemplate "+subtemplate);
if (includeSubtemplate)
{
/* To evaluate the IF chunk, make a new instance whose enclosingInstance
* points at 'self' so get attribute works. Otherwise, enclosingInstance
* points at the template used to make the precompiled code. We need a
* new template instance every time we exec this chunk to get the new
* "enclosing instance" pointer.
*/
StringTemplate s = subtemplate.getInstanceOf();
s.setEnclosingInstance(self);
n = s.write(outWriter);
}
else if (elseSubtemplate != null)
{
// evaluate ELSE clause if present and IF condition failed
StringTemplate s = elseSubtemplate.getInstanceOf();
s.setEnclosingInstance(self);
n = s.write(outWriter);
}
}
catch (RecognitionException re)
{
self.error("can't evaluate tree: " + exprTree.ToStringList(), re);
}
return n;
}
/// <summary>How to write this node to output; return how many char written </summary> public abstract int write(StringTemplate self, StringTemplateWriter outWriter);