the linearizer API now allows to detect metavariables. This is used for instancein the lookup where the tokens produced from the metavariables are interpreted as distinct from all other tokens.

src/runtime/python/pypgf.c

@@ -2039,13 +2039,20 @@ pgf_bracket_lzn_end_phrase(PgfLinFuncs** funcs, PgfCId cat, int fid, int lindex,
 	state->list = parent;
 }
 
+static void
+pgf_bracket_lzn_symbol_meta(PgfLinFuncs** funcs, PgfMetaId meta_id)
+{
+	pgf_bracket_lzn_symbol_token(funcs, "?");
+}
+
 static PgfLinFuncs pgf_bracket_lin_funcs = {
 	.symbol_token  = pgf_bracket_lzn_symbol_token,
 	.begin_phrase  = pgf_bracket_lzn_begin_phrase,
 	.end_phrase    = pgf_bracket_lzn_end_phrase,
 	.symbol_ne     = NULL,
 	.symbol_bind   = NULL,
-	.symbol_capit  = NULL
+	.symbol_capit  = NULL,
+	.symbol_meta   = pgf_bracket_lzn_symbol_meta
 };
 
 static PyObject*