private static bool CompileConditionOrLoop(int level, bool debug, Node container, Node node, NanCodeWriter wr, Scope parameterNames)
{
bool returns = false;
if (container.Children.Count < 1)
{
throw new ArgumentException(node.Text + " required parameter(s)");
}
bool isLoop = node.Text == "while";
var context = isLoop ? Context.Loop : Context.Condition;
var condition = new Node(false, -2);
condition.AddLast(container.Children.ElementAt(0));
condition.Text = "()";
var topOfBlock = wr.Position() - 1;
var body = new Node(false, -2);
for (int i = 1; i < container.Children.Count; i++)
{
body.AddLast(container.Children.ElementAt(i));
}
body.Text = "()";
var compiledBody = Compile(body, level + 1, debug, parameterNames, null, context);
returns |= compiledBody.ReturnsValues;
var opCodeCount = compiledBody.OpCodeCount();
if (isLoop)
{
opCodeCount++; // also skip the end unconditional jump
}
if (debug)
{
wr.Comment("// Compare condition for : " + node.Text + ", If false, skip " + compiledBody.OpCodeCount() + " element(s)");
}
if (Optimisations.IsSimpleComparion(condition, opCodeCount))
{
// output just the arguments
var argNodes = Optimisations.ReadSimpleComparison(condition, out var cmpOp, out var argCount);
var conditionArgs = Compile(argNodes, level + 1, debug, parameterNames, null, context);
wr.Merge(conditionArgs);
wr.CompoundCompareJump(cmpOp, argCount, (ushort)opCodeCount);
}
else
{
var conditionCode = Compile(condition, level + 1, debug, parameterNames, null, context);
if (debug)
{
wr.Comment("// Condition for : " + node.Text);
}
wr.Merge(conditionCode);
wr.CompareJump(opCodeCount);
}
wr.Merge(compiledBody);
if (debug)
{
wr.Comment("// End : " + node.Text);
}
if (isLoop)
{
var distance = wr.Position() - topOfBlock;
wr.UnconditionalJump((uint)distance);
}
return(returns);
}