public override Yarn.Type VisitElse_if_clause(YarnSpinnerV1Parser.Else_if_clauseContext context)
{
YarnSpinnerV1Parser.ExpressionContext expressionContext = context.expression();
this.CheckAndRewriteIfClause(context, expressionContext);
return(Type.Bool);
}
public override Yarn.IType VisitIf_clause(YarnSpinnerV1Parser.If_clauseContext context)
{
YarnSpinnerV1Parser.ExpressionContext expressionContext = context.expression();
this.CheckAndRewriteIfClause(context, expressionContext);
return(BuiltinTypes.Boolean);
}
private void CheckAndRewriteIfClause(ParserRuleContext context, YarnSpinnerV1Parser.ExpressionContext expressionContext)
{
// Evaluate the if statement's expression. In YS2, if
// statement expressions are required to be bool, but in
// YS1, they can be any type. In this upgrader, we 'permit'
// the type to also be int, and if it is, we'll later
// rewrite the expression to be of the type "EXP != 0" by
// running it through the checker with 'upgrades' enabled
var expressions = new[] { expressionContext };
var type = this.CheckOperation(context, expressions, "if statement", Yarn.Type.Bool, Yarn.Type.Number);
if (this.GenerateReplacements && type == Type.Number)
{
// This if statement resolved to a number expression,
// and we want to generate replacements. We'll generate
// a replacement that converts it to a bool.
// A 'simple expression' is on where the expression is
// just a value, eg <<if $x>>. A complex expression is
// one with operators (<<if $x + 1>>). We'll wrap
// complex expressions in parentheses.
var isSimpleExpression = expressionContext is YarnSpinnerV1Parser.ExpValueContext;
// Get the original text of expressionContext. We can't
// use "expressionContext.GetText()" here, because that
// just concatenates the text of all captured tokens,
// and doesn't include text on hidden channels (e.g.
// whitespace and comments).
var interval = new Interval(expressionContext.Start.StartIndex, expressionContext.Stop.StopIndex);
string originalText = expressionContext.Start.InputStream.GetText(interval);
string replacementText;
if (isSimpleExpression)
{
// No need to wrap
replacementText = originalText + " != 0";
}
else
{
// Wrap with parentheses
replacementText = "(" + originalText + ") != 0";
}
this.replacements.Add(new TextReplacement
{
Comment = "Converting if statement expression to a boolean",
OriginalText = originalText,
StartLine = expressionContext.Start.Line,
Start = expressionContext.Start.StartIndex,
ReplacementText = replacementText,
});
}
}
