Merge pull request #615 from egraphs-good/kirstenmg-type-rulesets

Add type helper error checking

dag_in_context/src/utility/canonicalize.egg

@@ -71,17 +71,24 @@
 ; Helper functions to remove one element from a tuple or type list
 ;                           tuple    idx
 (function TupleRemoveAt    (Expr     i64) Expr     :unextractable)
-(function TypeListRemoveAt (TypeList i64) TypeList :unextractable)
-
 (rewrite (TupleRemoveAt tuple idx)
          (Concat (SubTuple tuple 0 idx)
                  (SubTuple tuple (+ idx 1) (- len (+ idx 1))))
          :when ((= len (tuple-length tuple)))
          :ruleset always-run)
+(rule ((TupleRemoveAt tuple idx)
+       (= len (tuple-length tuple))
+       (>= idx len))
+      ((panic "Index out of bounds for TupleRemoveAt")) :ruleset always-run)
+
 
-(rewrite (TypeListRemoveAt (TNil)       _idx) (TNil) :ruleset always-run)
-(rewrite (TypeListRemoveAt (TCons x xs) 0   ) xs     :ruleset always-run)
+(function TypeListRemoveAt (TypeList i64) TypeList :unextractable)
+(rewrite (TypeListRemoveAt (TNil)       _idx) (TNil) :ruleset type-helpers)
+(rewrite (TypeListRemoveAt (TCons x xs) 0   ) xs     :ruleset type-helpers)
 (rewrite (TypeListRemoveAt (TCons x xs) idx)
          (TCons x (TypeListRemoveAt xs (- idx 1)))
          :when ((> idx 0))
-         :ruleset always-run)
+         :ruleset type-helpers)
+
+(rule ((TypeListRemoveAt (TNil) _idx))
+      ((panic "Index out of bounds for TypeListRemoveAt.")) :ruleset type-helpers)