allow always joining a scalar

changelog.md

@@ -2,8 +2,11 @@
 
 Uiua is not yet stable.
 
-<!-- This version is not yet released.
-If you are reading this on the website, then these changes are live here. -->
+## 0.4.0 - 2023-11-??
+This version is not yet released.
+If you are reading this on the website, then these changes are live here.
+### Language
+- [`join` `⊂`](https://uiua.org/docs/join) now always works with a scalar regardless of the shape of the other array
 
 ## 0.3.0 - 2023-11-19
 ### Language

src/algorithm/dyadic.rs

@@ -371,6 +371,10 @@ impl<T: ArrayValue> Array<T> {
                     self.fill_to_shape(row_shape, fill.clone());
                     other.fill_to_shape(&target_shape, fill);
                     target_shape
+                } else if self.rank() == 0 {
+                    let val = self.data.into_iter().next().unwrap();
+                    self.data = cowslice![val; other.shape().iter().skip(1).product()];
+                    other.shape
                 } else {
                     if other.rank() - self.rank() > 1 {
                         return Err(C::fill_error(ctx.error(format!(
@@ -440,6 +444,10 @@ impl<T: ArrayValue> Array<T> {
             self.fill_to_shape(&target_shape, fill.clone());
             other.fill_to_shape(row_shape, fill);
             target_shape
+        } else if other.rank() == 0 {
+            let val = other.data.into_iter().next().unwrap();
+            other.data = cowslice![val; self.shape().iter().skip(1).product()];
+            take(&mut self.shape)
         } else {
             if self.rank() <= other.rank() || self.rank() - other.rank() > 1 {
                 return Err(C::fill_error(ctx.error(format!(

tests/units.ua

@@ -151,3 +151,9 @@ ParseOrZero ← ⍣parse⋅⋅0
 ⍤⊃⋅∘≍ □↯1_¯1_4⇡24 ⍜(☇1)□ ↯2_3_4⇡24
 ⍤⊃⋅∘≍ ↯2_3≡□↯¯1_4⇡24 ⍜(☇1)≡□ ↯2_3_4⇡24
 ⍤⊃⋅∘≍ ≡□↯2_3_4⇡24 ⍜(☇2)≡□ ↯2_3_4⇡24
+
+⍤⊃⋅∘≍ [3 5] ⊂ 3 5
+⍤⊃⋅∘≍ [1 2 3 4] ⊂ 1 2_3_4
+⍤⊃⋅∘≍ [1 2 3 4] ⊂ 1_2_3 4
+⍤⊃⋅∘≍ [0_0_0 0_1_2 3_4_5] ⊂ 0 ↯2_3⇡6
+⍤⊃⋅∘≍ [0_1_2 3_4_5 0_0_0] ⊂:0 ↯2_3⇡6