private ScriptResult _EvaluateExpression(IExpr expr, bool createTempScope, bool hardTerminal = false)
{
if (null == expr)
{
LogError("Cannot evaluate null expression.");
return(null);
}
StackState stackState = defaultContext.stack.GetState();
if (createTempScope)
{
if (!defaultContext.stack.PushTerminalScope("<Evaluate>", defaultContext, hardTerminal))
{
LogError("_EvaluateExpression: stack overflow");
return(null);
}
}
ScriptResult result = new ScriptResult();
result.value = expr.Evaluate(defaultContext);
if (defaultContext.IsRuntimeErrorSet())
{
defaultContext.stack.RestoreState(stackState);
if (logCompileErrors)
{
LogError(defaultContext.GetRuntimeErrorString());
}
result.runtimeError = defaultContext.control.runtimeError;
result.success = false;
defaultContext.control.Clear();
}
else
{
result.success = true;
if (createTempScope)
{
defaultContext.stack.RestoreState(stackState);
defaultContext.control.Clear();
}
}
return(result);
}
public bool RestoreState(StackState state)
{
#if PEBBLE_DEBUG
Pb.Assert(state.varCount <= _varCount || state.callCount <= _callCount, "TODO: StackState invalid.");
#endif
while (_varCount > state.varCount)
{
Variable var = _varStack[_varCount - 1];
if (null != var)
{
if (var.unique)
{
_varStack[_varCount - 1] = null;
}
else
{
var.value = null;
var.name = "<deleted>";
}
}
--_varCount;
}
while (state.callCount < _callCount)
{
PopScope();
}
#if PEBBLE_DEBUG
Pb.Assert(state.callCount == _callCount, "whoops, call count different.");
#endif
#if PEBBLE_TRACESTACK
TraceLog("RestoreState");
TraceLog("");
#endif
return(true);
}
// This clears all variables from the stack and pops all calls.
// Global variables are not affected.
public void ClearStack()
{
StackState state = new StackState(0, 0);
RestoreState(state);
}