From 934fe4c48768f9d662c42c26ee697b7021f41050 Mon Sep 17 00:00:00 2001
From: Kai Schmidt <kaikaliischmidt@gmail.com>
Date: Wed, 26 Jun 2024 14:12:04 -0700
Subject: [PATCH] fix a crash in pervasive repeat and switch

---
 src/algorithm/loops.rs | 2 +-
 src/algorithm/mod.rs   | 2 +-
 tests/loops.ua         | 2 ++
 tests/units.ua         | 2 ++
 4 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/algorithm/loops.rs b/src/algorithm/loops.rs
index 16f7412d..3e317bea 100644
--- a/src/algorithm/loops.rs
+++ b/src/algorithm/loops.rs
@@ -93,7 +93,7 @@ pub fn repeat(with_inverse: bool, env: &mut Uiua) -> UiuaResult {
                     Err(row) => row.clone(),
                 };
                 // println!("row: {:?}", row);
-                if n.rank() > row.rank() {
+                if n.rank() > row.rank() || is_empty {
                     rows_to_sel.push(Err(row));
                 } else {
                     let row_shape = row.shape()[n.rank()..].into();
diff --git a/src/algorithm/mod.rs b/src/algorithm/mod.rs
index 6ab4ed72..91520aff 100644
--- a/src/algorithm/mod.rs
+++ b/src/algorithm/mod.rs
@@ -542,7 +542,7 @@ pub fn switch(
                     Err(row) => row.clone(),
                 };
                 // println!("row: {:?}", row);
-                if selector.rank() > row.rank() {
+                if selector.rank() > row.rank() || is_empty {
                     rows_to_sel.push(Err(row));
                 } else {
                     let row_shape = row.shape()[selector.rank()..].into();
diff --git a/tests/loops.ua b/tests/loops.ua
index 76371bb6..4eebdc32 100644
--- a/tests/loops.ua
+++ b/tests/loops.ua
@@ -228,6 +228,8 @@ A ← ↯2_3_4⇡24
 ⍤⟜≍: [+1.+1. 2_4_6] ⍥(+1) [+1.+1. 1_2_3] ¤[1 2 3]
 ⍤⟜≍: [..4_5_6] ⍥(+1) [+1.+1. 1_2_3] [1 2 3]
 ⍤⟜≍: 5 ⍥(+1) ¯5 10
+⍤⟜≍: ↯0_3e ⍥∘[] ¤[1 2 3]
+⍤⟜≍: ↯0_0e ⍥∘[] ¤[]
 
 # Do
 ⍤⟜≍: 1024 ⍢(×2)(<1000) 1
diff --git a/tests/units.ua b/tests/units.ua
index c208c9b4..aeb8db24 100644
--- a/tests/units.ua
+++ b/tests/units.ua
@@ -183,6 +183,8 @@ F ← ⨬(¯|+1|×10|∞)
 ⍤⟜≍: [¯5 6 50 ∞] F [0 1 2 3] 5
 ⍤⟜≍: [¯1_2_10_∞ ¯2_3_20_∞ ¯3_4_30_∞] F [..0_1_2_3] [1 2 3]
 ⍤⟜≍: [..¯5_6_50_∞] F [..0_1_2_3] 5
+⍤⟜≍: ↯0_3e ⨬∘∘[] ¤[1 2 3]
+⍤⟜≍: ↯0_0e ⨬∘∘[] ¤[]
 
 # Where
 ⍤⟜≍: [0 3 5 6] ⊚[1 0 0 1 0 1 1 0]