The Precedence Issue of `as` and Binary Operations

[A4-Tacks]

link 01mf02/jaq#261

$ jq -n '"x" as $n | "a"+"y" as $s | $n+","+$s'
"ax,y"

Like:

$ jq -n '"x" as $n | "a"+("y" as $s | $n+","+$s)'
"ax,y"

Or (scope has some impact):

jq: error: $s is not defined at <top-level>, line 1:
"x" as $n | "a"+("y" as $s | $n)+","+$s
jq: 1 compile error

Intuitively, it should be:

$ jq -n '"x" as $n | ("a"+"y") as $s | $n+","+$s'
"x,ay"