From 1f1c0849523273ab7db3f376addfd03ad84bbab6 Mon Sep 17 00:00:00 2001
From: Tilman Hinnerichs <tilman@hinnerichs.com>
Date: Tue, 14 May 2024 15:57:06 +0200
Subject: [PATCH] Add typecheck for right hande side of rules + check equality
 with ==

---
 src/grammar_base.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/grammar_base.jl b/src/grammar_base.jl
index 14e140c..ef99883 100644
--- a/src/grammar_base.jl
+++ b/src/grammar_base.jl
@@ -214,7 +214,7 @@ function add_rule!(g::AbstractGrammar, e::Expr)
             # Only add a rule if it does not exist yet. Check for existance
             # with strict equality so that true and 1 are not considered
             # equal. that means we can't use `in` or `∈` for equality checking.
-            if !any(r === rule for rule ∈ g.rules)
+            if !any(r === rule || typeof(r)==Expr && r == rule for rule ∈ g.rules)
                 push!(g.rules, r)
                 push!(g.iseval, iseval(rule))
                 push!(g.types, s)