IReadOnlyList <Ast.Variant> GetVariants(FtlParserStream ps)
{
var variants = new List <Ast.Variant>();
bool hasDefault = false;
while (true)
{
ps.ExpectIndent();
var variant = GetVariant(ps, hasDefault);
if (variant.IsDefault)
{
hasDefault = true;
}
variants.Add(variant);
if (!ps.IsPeekNextLineVariantStart())
{
break;
}
}
if (!hasDefault)
{
throw new ParseException("E0010");
}
return(variants);
}
Ast.SyntaxNode _GetVariantList(FtlParserStream ps)
{
ps.ExpectChar('{');
ps.SkipInlineWs();
var variants = GetVariants(ps);
ps.ExpectIndent();
ps.ExpectChar('}');
return(new Ast.VariantList(variants));
}
IReadOnlyList <Ast.Attribute> GetAttributes(FtlParserStream ps)
{
var attrs = new List <Ast.Attribute>();
while (true)
{
ps.ExpectIndent();
var attr = GetAttribute(ps);
attrs.Add(attr);
if (!ps.IsPeekNextLineAttributeStart())
{
break;
}
}
return(attrs);
}
Ast.SyntaxNode _GetExpression(FtlParserStream ps)
{
ps.SkipInlineWs();
var selector = GetSelectorExpression(ps);
ps.SkipInlineWs();
if (ps.CurrentIs('-'))
{
ps.Peek();
if (!ps.CurrentPeekIs('>'))
{
ps.ResetPeek();
return(selector);
}
if (selector is Ast.MessageReference)
{
throw new ParseException("E0016");
}
if (selector is Ast.AttributeExpression ae &&
ae.Ref is Ast.MessageReference)
{
throw new ParseException("E0018");
}
if (selector is Ast.VariantExpression)
{
throw new ParseException("E0017");
}
ps.Next();
ps.Next();
ps.SkipInlineWs();
var variants = GetVariants(ps);
if (variants.Count == 0)
{
throw new ParseException("E0011");
}
// VariantLists are only allowed in other VariantLists.
if (variants.Any(v => v.Value is Ast.VariantList))
{
throw new ParseException("E0023");
}
ps.ExpectIndent();
return(new Ast.SelectExpression(selector, variants));
}
else if (selector is Ast.AttributeExpression ae &&
ae.Ref is Ast.TermReference)
{
throw new ParseException("E0019");
}
return(selector);
}
