use fill for reducing group and partition defaults

changelog.md

@@ -14,7 +14,8 @@ This version is not yet released. If you are reading this on the website, then t
  - [`insert`](https://uiua.org/docs/insert)
  - [`remove`](https://uiua.org/docs/remove)
 - Add experimental [`bind`](https://uiua.org/docs/bind) modifier, which binds local values within a function
-- [`fill` `⬚`](https://uiua.org/docs/fill) can now be used to specify default accumulators for [`reduce` `/`](https://uiua.org/docs/reduce)
+- [`fill` `⬚`](https://uiua.org/docs/fill) can now be used to specify default accumulators for [`reduce` `/`](https://uiua.org/docs/reduce), [`group` `⊕`](https://uiua.org/docs/group), and [`partition` `⊜`](https://uiua.org/docs/partition)
+ - Reducing [`group` `⊕`](https://uiua.org/docs/group) and [`partition` `⊜`](https://uiua.org/docs/partition) no longer take a required accumulator
 ### Interpreter
 - The internal byte array type is now used in more places, which should improve performance a bit
 - Lots of bug and crash fixes

src/algorithm/loops.rs

@@ -340,10 +340,18 @@ fn collapse_groups(
  }
  }
  (2, 1) => {
- let mut acc = env.pop(1)?;
- let indices = env.pop(2)?.as_ints(env, red_indices_error)?;
- let values = env.pop(3)?;
- let groups = get_groups(values, &indices, env)?;
+ let indices = env.pop(1)?.as_ints(env, red_indices_error)?;
+ let values = env.pop(2)?;
+ let mut groups = get_groups(values, &indices, env)?.into_iter();
+ let mut acc = match env.box_fill() {
+ Ok(acc) => acc.0,
+ Err(e) => groups.next().ok_or_else(|| {
+ env.error(format!(
+ "Cannot do aggregating {} with no groups{e}",
+ prim.format()
+ ))
+ })?,
+ };
  for row in groups {
  env.push(row);
  env.push(acc);

src/check.rs

@@ -336,19 +336,7 @@ impl<'a> VirtualEnv<'a> {
  }
  Group | Partition => {
  let sig = self.pop_func()?.signature();
- let args = match sig.args {
- 0 => 2,
- 1 => 2,
- 2 => 3,
- _ => {
- return Err(format!(
- "{prim}'s function must take at most 2 arguments, \
- but its signature is {sig}",
- )
- .into())
- }
- };
- self.handle_args_outputs(args, sig.outputs)?;
+ self.handle_args_outputs(2, sig.outputs)?;
  }
  Spawn => {
  let sig = self.pop_func()?.signature();

src/primitive/defs.rs

@@ -1168,8 +1168,8 @@ primitive!(
  /// The function then processes each group in order. The result depends on what the function is.
  /// If the function takes 0 or 1 arguments, then [group] behaves like [rows]. This is called *iterating* [group].
  /// ex: ⊕∘ [0 2 2 1 0 1] [1 2 3 4 5 6]
- /// If the function takes 2 or more arguments, then [group] requires an accumulator and behaves like [fold]. This is called *accumulating* [group].
- /// ex: ⊕⊂ [] [0 2 2 1 0 1] [1 2 3 4 5 6]
+ /// If the function takes 2 or more arguments, then [group] behaves like [reduce]. This is called *reducing* [group].
+ /// ex: ⊕⊂ [0 2 2 1 0 1] [1 2 3 4 5 6]
  /// If the values returned by the function do not have the same [shape], concatenation will fail.
  /// ex! ⊕∘ [0 1 0 2 1 1] [1 2 3 4 5 6]
  /// It is common to use [box] to encapsulate groups of different [shape]s.
@@ -1198,8 +1198,8 @@ primitive!(
  /// The function then processes each group in order. The result depends on what the function is.
  /// If the function takes 0 or 1 arguments, then [partition] behaves like [rows]. This is called *iterating* [partition].
  /// ex: ⊜∘ [0 0 2 2 1 1 3 3] [1 2 3 4 5 6 7 8]
- /// If the function takes 2 or more arguments, then [partition] requires an accumulator and behaves like [fold]. This is called *accumulating* [partition].
- /// ex: ⊜⊂ [] [0 0 2 2 1 1 3 3] [1 2 3 4 5 6 7 8]
+ /// If the function takes 2 or more arguments, then [partition] behaves like [reduce]. This is called *reducing* [partition].
+ /// ex: ⊜⊂ [0 0 2 2 1 1 3 3] [1 2 3 4 5 6 7 8]
  /// If the values returned by the function do not have the same [shape], concatenation will fail.
  /// ex! ⊜∘ [0 2 3 3 3 0 1 1] [1 2 3 4 5 6 7 8]
  /// It is common to use [box] to encapsulate groups of different [shape]s.

tests/loops.ua

@@ -46,10 +46,10 @@
 ⍤⊃⋅∘≍ ↯0_3[] ≡(⊂⊂) [] 5 []
 ⍤⊃⋅∘≍ ↯0_3[] ≡(⊂⊂) 5 [] []
 
-⍤⊃⋅∘≍ ⇡6 ⊜⊂ [] [1 1 2 2 3 3] ⇡6
-⍤⊃⋅∘≍ ⇡6 /⊂⊜∘[1 1 2 2 3 3] ⇡6
-⍤⊃⋅∘≍ ⇡6 ⊕⊂ [] [0 0 1 1 2 2] ⇡6
-⍤⊃⋅∘≍ ⇡6 /⊂⊕∘[0 0 1 1 2 2] ⇡6
+⍤⊃⋅∘≍ ⇡6 ⊜⊂ [1 1 2 2 3 3] ⇡6
+⍤⊃⋅∘≍ ⇡6 /⊂⊜∘ [1 1 2 2 3 3] ⇡6
+⍤⊃⋅∘≍ ⇡6 ⊕⊂ [0 0 1 1 2 2] ⇡6
+⍤⊃⋅∘≍ ⇡6 /⊂⊕∘ [0 0 1 1 2 2] ⇡6
 
 ⍤⊃⋅∘≍ 1024 ⍢(×2)(<1000) 1
 ⍤⊃⋅∘≍ 1024 ⍢(×2)(<1000.) 1