// for the shortcut options (-> line of text <<if expression>>
// indent statements dedent)+
public override int VisitShortcut_option_statement(YarnSpinnerParser.Shortcut_option_statementContext context)
{
string endOfGroupLabel = compiler.RegisterLabel("group_end");
var labels = new List <string>();
int optionCount = 0;
// For each option, create an internal destination label that,
// if the user selects the option, control flow jumps to. Then,
// evaluate its associated line_statement, and use that as the
// option text. Finally, add this option to the list of
// upcoming options.
foreach (var shortcut in context.shortcut_option())
{
// Generate the name of internal label that we'll jump to
// if this option is selected. We'll emit the label itself
// later.
string optionDestinationLabel = compiler.RegisterLabel($"shortcutoption_{compiler.CurrentNode.Name ?? "node"}_{optionCount + 1}");
labels.Add(optionDestinationLabel);
// This line statement may have a condition on it. If it
// does, emit code that evaluates the condition, and add a
// flag on the 'Add Option' instruction that indicates that
// a condition exists.
bool hasLineCondition = false;
if (shortcut.line_statement().line_condition() != null)
{
// Evaluate the condition, and leave it on the stack
Visit(shortcut.line_statement().line_condition().expression());
hasLineCondition = true;
}
// We can now prepare and add the option.
// Start by figuring out the text that we want to add. This
// will involve evaluating any inline expressions.
var expressionCount = GenerateCodeForExpressionsInFormattedText(shortcut.line_statement().line_formatted_text().children);
// Get the line ID from the hashtags if it has one
string lineID = Compiler.GetLineID(shortcut.line_statement().hashtag());
if (lineID == null)
{
throw new ParseException("No line ID provided");
}
// And add this option to the list.
compiler.Emit(
OpCode.AddOption,
new Operand(lineID),
new Operand(optionDestinationLabel),
new Operand(expressionCount),
new Operand(hasLineCondition));
optionCount++;
}
// All of the options that we intend to show are now ready to
// go.
compiler.Emit(OpCode.ShowOptions);
// The top of the stack now contains the name of the label we
// want to jump to. Jump to it now.
compiler.Emit(OpCode.Jump);
// We'll now emit the labels and code associated with each
// option.
optionCount = 0;
foreach (var shortcut in context.shortcut_option())
{
// Emit the label for this option's code
compiler.CurrentNode.Labels.Add(labels[optionCount], compiler.CurrentNode.Instructions.Count);
// Run through all the children statements of the shortcut
// option.
foreach (var child in shortcut.statement())
{
Visit(child);
}
// Jump to the end of this shortcut option group.
compiler.Emit(OpCode.JumpTo, new Operand(endOfGroupLabel));
optionCount++;
}
// We made it to the end! Mark the end of the group, so we can
// jump to it.
compiler.CurrentNode.Labels.Add(endOfGroupLabel, compiler.CurrentNode.Instructions.Count);
compiler.Emit(OpCode.Pop);
return(0);
}
public CodeGenerationVisitor(Compiler compiler)
{
this.compiler = compiler;
this.loadOperators();
}