Add JuliaLang/JuliaSyntax.jl#525 to NEWS.md, flisp parser, and REPL (#57143)

Now that JuliaLang/JuliaSyntax.jl#525 has been merged, also add it to
the flisp parser and REPL, and document it!

Author: pthariensflame

NEWS.md

@@ -5,6 +5,9 @@ New language features
 ---------------------
 
   - New `Base.@acquire` macro for a non-closure version of `Base.acquire(f, s::Base.Semaphore)`, like `@lock`. ([#56845])
+  - The character U+1F8B2 🢲 (RIGHTWARDS ARROW WITH LOWER HOOK), newly added by Unicode 16,
+    is now a valid operator with arrow precedence, accessible as `\hookunderrightarrow` at the REPL.
+    ([JuliaLang/JuliaSyntax.jl#525], [#57143])
 
 Language changes
 ----------------

src/flisp/julia_extensions.c

@@ -130,6 +130,9 @@ JL_DLLEXPORT int jl_id_start_char(uint32_t wc)
         return 1;
     if (wc < 0xA1 || wc > 0x10ffff)
         return 0;
+    // "Rightwards Arrow with Lower Hook"
+    if (wc == 0x1f8b2)
+    	return 1;
     return is_wc_cat_id_start(wc, utf8proc_category((utf8proc_int32_t) wc));
 }
 
@@ -147,7 +150,9 @@ JL_DLLEXPORT int jl_id_char(uint32_t wc)
         cat == UTF8PROC_CATEGORY_SK || cat == UTF8PROC_CATEGORY_ME ||
         cat == UTF8PROC_CATEGORY_NO ||
         // primes (single, double, triple, their reverses, and quadruple)
-        (wc >= 0x2032 && wc <= 0x2037) || (wc == 0x2057))
+        (wc >= 0x2032 && wc <= 0x2037) || (wc == 0x2057) ||
+        // "Rightwards Arrow with Lower Hook"
+        wc == 0x1f8b2)
         return 1;
     return 0;
 }

src/julia-parser.scm

@@ -10,7 +10,7 @@
 ;; comma - higher than assignment outside parentheses, lower when inside
 (define prec-pair (add-dots '(=>)))
 (define prec-conditional '(?))
-(define prec-arrow       (add-dots '(← → ↔ ↚ ↛ ↞ ↠ ↢ ↣ ↦ ↤ ↮ ⇎ ⇍ ⇏ ⇐ ⇒ ⇔ ⇴ ⇶ ⇷ ⇸ ⇹ ⇺ ⇻ ⇼ ⇽ ⇾ ⇿ ⟵ ⟶ ⟷ ⟹ ⟺ ⟻ ⟼ ⟽ ⟾ ⟿ ⤀ ⤁ ⤂ ⤃ ⤄ ⤅ ⤆ ⤇ ⤌ ⤍ ⤎ ⤏ ⤐ ⤑ ⤔ ⤕ ⤖ ⤗ ⤘ ⤝ ⤞ ⤟ ⤠ ⥄ ⥅ ⥆ ⥇ ⥈ ⥊ ⥋ ⥎ ⥐ ⥒ ⥓ ⥖ ⥗ ⥚ ⥛ ⥞ ⥟ ⥢ ⥤ ⥦ ⥧ ⥨ ⥩ ⥪ ⥫ ⥬ ⥭ ⥰ ⧴ ⬱ ⬰ ⬲ ⬳ ⬴ ⬵ ⬶ ⬷ ⬸ ⬹ ⬺ ⬻ ⬼ ⬽ ⬾ ⬿ ⭀ ⭁ ⭂ ⭃ ⥷ ⭄ ⥺ ⭇ ⭈ ⭉ ⭊ ⭋ ⭌ ￩ ￫ ⇜ ⇝ ↜ ↝ ↩ ↪ ↫ ↬ ↼ ↽ ⇀ ⇁ ⇄ ⇆ ⇇ ⇉ ⇋ ⇌ ⇚ ⇛ ⇠ ⇢ ↷ ↶ ↺ ↻ --> <-- <-->)))
+(define prec-arrow       (add-dots '(← → ↔ ↚ ↛ ↞ ↠ ↢ ↣ ↦ ↤ ↮ ⇎ ⇍ ⇏ ⇐ ⇒ ⇔ ⇴ ⇶ ⇷ ⇸ ⇹ ⇺ ⇻ ⇼ ⇽ ⇾ ⇿ ⟵ ⟶ ⟷ ⟹ ⟺ ⟻ ⟼ ⟽ ⟾ ⟿ ⤀ ⤁ ⤂ ⤃ ⤄ ⤅ ⤆ ⤇ ⤌ ⤍ ⤎ ⤏ ⤐ ⤑ ⤔ ⤕ ⤖ ⤗ ⤘ ⤝ ⤞ ⤟ ⤠ ⥄ ⥅ ⥆ ⥇ ⥈ ⥊ ⥋ ⥎ ⥐ ⥒ ⥓ ⥖ ⥗ ⥚ ⥛ ⥞ ⥟ ⥢ ⥤ ⥦ ⥧ ⥨ ⥩ ⥪ ⥫ ⥬ ⥭ ⥰ ⧴ ⬱ ⬰ ⬲ ⬳ ⬴ ⬵ ⬶ ⬷ ⬸ ⬹ ⬺ ⬻ ⬼ ⬽ ⬾ ⬿ ⭀ ⭁ ⭂ ⭃ ⥷ ⭄ ⥺ ⭇ ⭈ ⭉ ⭊ ⭋ ⭌ ￩ ￫ ⇜ ⇝ ↜ ↝ ↩ ↪ ↫ ↬ ↼ ↽ ⇀ ⇁ ⇄ ⇆ ⇇ ⇉ ⇋ ⇌ ⇚ ⇛ ⇠ ⇢ ↷ ↶ ↺ ↻ --> <-- <--> 🢲)))
 (define prec-lazy-or     (add-dots '(|\|\||)))
 (define prec-lazy-and    (add-dots '(&&)))
 (define prec-comparison

stdlib/REPL/src/latex_symbols.jl

@@ -517,6 +517,7 @@ const latex_symbols = Dict(
     "\\mapsto" => "↦",
     "\\hookleftarrow" => "↩",
     "\\hookrightarrow" => "↪",
+    "\\hookunderrightarrow" => "🢲",
     "\\looparrowleft" => "↫",
     "\\looparrowright" => "↬",
     "\\leftrightsquigarrow" => "↭",

test/syntax.jl

@@ -2287,6 +2287,11 @@ end
     @test Meta.parse("a ⥷ b") == Expr(:call, :⥷, :a, :b)
 end
 
+# issue 57143
+@testset "binary 🢲" begin
+    @test Meta.parse("a 🢲 b") == Expr(:call, :🢲, :a, :b)
+end
+
 # only allow certain characters after interpolated vars (#25231)
 @test_parseerror("\"\$x෴  \"",
                  "interpolated variable \$x ends with invalid character \"෴\"; use \"\$(x)\" instead.")