void GenerateCode(Node node, Parser.Expression expression)
{
// Expressions are either plain values, or function calls
switch (expression.type)
{
case Parser.Expression.Type.Value:
// Plain value? Emit that
GenerateCode(node, expression.value);
break;
case Parser.Expression.Type.FunctionCall:
// Evaluate all parameter expressions (which will
// push them to the stack)
foreach (var parameter in expression.parameters)
{
GenerateCode(node, parameter);
}
// If this function has a variable number of parameters, put
// the number of parameters that were passed onto the stack
if (expression.function.paramCount == -1)
{
Emit(node, ByteCode.PushNumber, expression.parameters.Count);
}
// And then call the function
Emit(node, ByteCode.CallFunc, expression.function.name);
break;
}
}
private Yarn.Value EvaluateExpression(Parser.Expression expression)
{
if (expression == null)
{
return(new Yarn.Value());
}
switch (expression.type)
{
case Parser.Expression.Type.Value:
// just a regular value? return it
return(EvaluateValue(expression.value.value));
case Parser.Expression.Type.FunctionCall:
// get the function
var func = expression.function;
// evaluate all parameters
var evaluatedParameters = new List <Value> ();
foreach (var param in expression.parameters)
{
var expr = EvaluateExpression(param);
evaluatedParameters.Add(expr);
}
var result = func.InvokeWithArray(evaluatedParameters.ToArray());
return(result);
}
throw new NotImplementedException("Unimplemented expression type " + expression.type.ToString());
}
