add ꜛ, ꜜ and ꜝ as operator suffix (#37542)

* add ꜛ, ꜜ and ꜝ as operator suffix

* Update NEWS.md

tweak wording

Co-authored-by: Steven G. Johnson <stevenj@mit.edu>

Author: simeonschaub

NEWS.md

@@ -13,6 +13,9 @@ New language features
 * The library name passed to `ccall` or `@ccall` can now be an expression involving
   global variables and function calls. The expression will be evaluated the first
   time the `ccall` executes ([#36458]).
+* `ꜛ` (U+A71B), `ꜜ` (U+A71C) and `ꜝ` (U+A71D) can now also be used as operator
+  suffixes. They can be tab-completed from `\^uparrow`, `\^downarrow` and `\^!` in the REPL
+  ([#37542]).
 
 Language changes
 ----------------

src/flisp/julia_opsuffs.h

@@ -122,5 +122,8 @@ static const uint32_t opsuffs[] = {
    0x0000209b, // ₛ
    0x0000209c, // ₜ
    0x00002c7c, // ⱼ
-   0x00002c7d  // ⱽ
+   0x00002c7d, // ⱽ
+   0x0000a71b, // ꜛ
+   0x0000a71c, // ꜜ
+   0x0000a71d  // ꜝ
 };

stdlib/REPL/src/latex_symbols.jl

@@ -183,6 +183,9 @@ const latex_symbols = Dict(
     "\\^phi" => "ᵠ",
     "\\^chi" => "ᵡ",
     "\\^Phi" => "ᶲ",
+    "\\^uparrow" => "ꜛ",
+    "\\^downarrow" => "ꜜ",
+    "\\^!" => "ꜝ",
 
     # Subscripts
     "\\_0" => "₀",

test/syntax.jl

@@ -2340,3 +2340,5 @@ if isodd(1) && all(iseven(2) for c in ())
 else
     @test false
 end
+
+@test :(a +ꜝ b) == Expr(:call, :+ꜝ, :a, :b)