internal ParseResult Parse(ParseContext parentContext)
{
var ctx = new ParseContext(parentContext, this);
if (!parentContext.IsUnique(ctx))
{
return(ctx.Error("Infinite parsing loop detected."));
}
ParseResult failed = null;
SymbolExpectedError tailError = null;
var children = OnParse(ctx)
.TakeWhile(x => (failed = failed ?? (x.Success ? null : x)) == null &&
(tailError = x.TailError ?? tailError) == tailError)
.SelectMany(x => x.FlattenHierarchy ? x : Single(x))
.ToArray();
if (failed != null)
{
tailError = ctx.Expected(tailError, failed.Error as SymbolExpectedError);
}
return((failed != null && failed.Fatal)
? failed.Error
: SubstituteResult(new ParseResult(ctx, failed != null
? ctx.Expected(failed.Error as SymbolExpectedError, tailError)
: tailError, children)));
}
protected override IEnumerable <ParseResult> OnParse(ParseContext ctx)
{
yield return(ctx.Error(Reason));
}