Re: yypcontext_expected_tokens does not list optional components in grammar

> On 3 Dec 2025, at 22:31, Jan K. <[email protected]> wrote:
>=20
> I'm trying to use the yyreport_syntax_error function to report syntax
> errors in a grammar that has some optional components. In such case
> the yypcontext_expected_tokens does not list the optional components
> among the expected. How can I make it do that?

It could be that using a parser based on IELR or LR fixes it. The =
default is LALR, which does not always see the error tokens immediately, =
but may perform some reductions first.

See the section 5.8 =E2=80=9CTuning LR=E2=80=9D in the Bison manual. The =
command is
%define lr.type type
where type is one of lalr, ielr, canonical-lr, the first is the default.