public override ArmadaLValue ApplySeqSelect(IToken i_tok, ResolutionContext context, ArmadaRValue idx1, Type ty) { var me = GetValueInLValueState(context); var sz = AH.MakeCardinalityExpr(me); var newUndefinedBehaviorAvoidance = GetUndefinedBehaviorAvoidanceConstraint() + idx1.UndefinedBehaviorAvoidance; var idx1val = AH.ConvertToIntIfNotInt(idx1.Val); if (type is SizedArrayType) { SizedArrayType st = (SizedArrayType)type; if (!AH.TypesMatch(st.Range, ty)) { context.Fail(i_tok, $"Element of type {st.Range} used as type {ty}"); return(null); } newUndefinedBehaviorAvoidance.Add(AH.MakeLeExpr(AH.MakeZero(), idx1val)); newUndefinedBehaviorAvoidance.Add(AH.MakeLtExpr(idx1val, sz)); } else if (type is SeqType) { newUndefinedBehaviorAvoidance.Add(AH.MakeLeExpr(AH.MakeZero(), idx1val)); newUndefinedBehaviorAvoidance.Add(AH.MakeLtExpr(idx1val, sz)); } else if (type is MapType) { newUndefinedBehaviorAvoidance.Add(AH.MakeInExpr(idx1val, me)); } else { context.Fail(i_tok, $"Attempt to index into something that isn't an array, seq, or map"); return(null); } return(new UnaddressableIndexArmadaLValue(i_tok, ty, this, newUndefinedBehaviorAvoidance, idx1val)); }