Implement parse subscripts (#786)

* implement base subscripts

* add tests for parse subscripts

* document parse subscripts

* Add an extra test

Co-authored-by: Tau <[email protected]>

---------

Co-authored-by: Tau <[email protected]>

Author: Marcos-cat

changelog.md

@@ -15,6 +15,7 @@ This version is not yet released. If you are reading this on the website, then t
 - **Breaking Change** - [`dip ⊙`](https://uiua.org/docs/dip) and [`on ⟜`](https://uiua.org/docs/on) function packs no longer apply their modifier to the leftmost function
   - This change makes most usecases of these function packs cleaner, as `A⊙(B|C)` changes to `⊙(A|B|C)` and likewise for [`on ⟜`](https://uiua.org/docs/on)
 - **Breaking Change** - The FFI function API has been changed considerably, read more in the documentation for [`&ffi`](https://uiua.org/docs/&ffi), [`&memcpy`](https://uiua.org/docs/&memcpy), and [`&memset`](https://uiua.org/docs/&memset)
+- [`parse ⋕`](https://uiua.org/docs/parse) can be subscripted to parse strings in different bases
 - Allow for private [modules](https://uiua.org/tutorial/modules#private-scoped-modules), [imports](https://uiua.org/tutorial/modules#private-imports), and [data definitions](https://uiua.org/tutorial/datadefs#visibility)
 - Add array pack syntactic sugar. This lets you write code like `[⊃(+|×)]` as `⊃[+|×]`.
 - Subscripts can now be typed with `,` instead of `__`s

parser/src/defs.rs

@@ -865,9 +865,14 @@ primitive!(
     /// ex: ⋕ {"5" "24" "106"}
     /// ex: ⋕ .↯3_4 "012"
     ///
+    /// [parse] can take a subscript to parse in a different base. Bases `1` through `36` are supported as well as [Base64](https://en.wikipedia.org/wiki/Base64).
+    /// ex: ⋕₁₆"beef"
+    /// ex: ⋕₂ "-101010"
+    ///
     /// [un][parse] will convert a scalar number into a string.
     /// ex: °⋕ 58
     /// ex: °⋕ 6.283185307179586
+    /// ex: °⋕₁₆ 250.9375
     /// [un][parse] on a non-scalar number array will [box] each string.
     /// ex: °⋕ 1_2_3
     /// ex: °⋕ ↯3_4⇡12

site/src/other.rs

@@ -565,6 +565,7 @@ pub fn Subscripts() -> impl IntoView {
         subscript(First, "First N values", "⊢₂ \"hello\""),
         subscript(Last, "Last N values", "⊣₂ \"hello\""),
         subscript(Bits, "Force N bits", "⋯₄ [1 2 3]"),
+        subscript(Parse, "Parse in base N", "⋕₁₆ \"beef\""),
         subscript(Base, "Base N", "⊥₁₀ 123"),
         subscript(Keep, "Keep along N axes", "▽₂ 1.5 [1_2_3_4 5_6_7_8]"),
         subscript(Rand, "Random integer", "⚂₁₀₀"),