fix operator precendence printing of a in b. fixes #13822

Author: vtjnash

src/julia-parser.scm

@@ -59,6 +59,7 @@
                              (pushprec (cdr L) (+ prec 1)))))
                      (pushprec (map eval prec-names) 1)
                      t))
+(put! prec-table 'in (get prec-table '== 0)) ; add `in` to the prec-table
 (define (operator-precedence op) (get prec-table op 0))
 
 (define unary-ops '(+ - ! ¬ ~ |<:| |>:| √ ∛ ∜))

test/show.jl

@@ -78,6 +78,8 @@ end
 #@test_repr "w = (x = y) = z" # Doesn't pass, but it's an invalid assignment loc
 @test_repr "a & b && c"
 @test_repr "a & (b && c)"
+@test_repr "(a => b) in c"
+@test_repr "a => b in c"
 
 # precedence tie resolution
 @test_repr "(a * b) * (c * d)"