fix #21440, parsing +(x::T,y::T) where {T}

src/julia-parser.scm

@@ -25,9 +25,11 @@
 (define prec-bitshift    (add-dots '(<< >> >>>)))
 (define prec-times       (add-dots '(* / ÷ % & ⋅ ∘ × |\\| ∩ ∧ ⊗ ⊘ ⊙ ⊚ ⊛ ⊠ ⊡ ⊓ ∗ ∙ ∤ ⅋ ≀ ⊼ ⋄ ⋆ ⋇ ⋉ ⋊ ⋋ ⋌ ⋏ ⋒ ⟑ ⦸ ⦼ ⦾ ⦿ ⧶ ⧷ ⨇ ⨰ ⨱ ⨲ ⨳ ⨴ ⨵ ⨶ ⨷ ⨸ ⨻ ⨼ ⨽ ⩀ ⩃ ⩄ ⩋ ⩍ ⩎ ⩑ ⩓ ⩕ ⩘ ⩚ ⩜ ⩞ ⩟ ⩠ ⫛ ⊍ ▷ ⨝ ⟕ ⟖ ⟗)))
 (define prec-rational    (add-dots '(//)))
+;; `where`
+;; unary
 (define prec-power       (add-dots '(^ ↑ ↓ ⇵ ⟰ ⟱ ⤈ ⤉ ⤊ ⤋ ⤒ ⤓ ⥉ ⥌ ⥍ ⥏ ⥑ ⥔ ⥕ ⥘ ⥙ ⥜ ⥝ ⥠ ⥡ ⥣ ⥥ ⥮ ⥯ ￪ ￬)))
 (define prec-decl        '(|::|))
-;; `where`
+;; `where` occurring after `::`
 (define prec-dot         '(|.|))
 
 (define prec-names '(prec-assignment
@@ -594,7 +596,8 @@
          ex))))
 
 (define (parse-where s)
-  (let ((ex (parse-call s)))
+  ;; `where` needs to be below unary for `+(x::T,y::T) where {T} = ...` to work
+  (let ((ex (parse-unary s)))
     (if (and where-enabled
              (eq? (peek-token s) 'where))
         (parse-where-chain s ex)
@@ -819,7 +822,7 @@
 
 (define (parse-term s) (parse-with-chains s parse-rational is-prec-times? '(*)))
 
-(define (parse-rational s) (parse-LtoR s parse-unary is-prec-rational?))
+(define (parse-rational s) (parse-LtoR s parse-where is-prec-rational?))
 
 (define (parse-pipes s)    (parse-LtoR s parse-range is-prec-pipe?))
 
@@ -954,7 +957,7 @@
   (parse-factor-h s parse-decl is-prec-power?))
 
 (define (parse-decl s)
-  (let loop ((ex (parse-where s)))
+  (let loop ((ex (parse-call s)))
     (let ((t (peek-token s)))
       (case t
         ((|::|) (take-token s)

test/parse.jl

@@ -1103,3 +1103,6 @@ end
       Expr(:toplevel,
            Expr(:using, Symbol("."), :B),
            Expr(:using, Symbol("."), :C))
+
+# issue #21440
+@test parse("+(x::T,y::T) where {T} = 0") == parse("(+)(x::T,y::T) where {T} = 0")