each for nested blocks

deep_each.red

each: function [a[block!] b [function!]] [
    collect [
        foreach el a [
            either block? el [
                keep/only each el :b
            ][
                keep b el
            ]
        ]
    ]
]
f: function [a] [a * 10]
probe each [
 1
 2
 3
] :f
; [
    ; 10 
    ; 20 
    ; 30
; ]

probe each [
 1
 2
 3 [
    4
    5
    6
 ]
] :f
; [
    ; 10 
    ; 20 
    ; 30 [
        ; 40 
        ; 50 
        ; 60
    ; ]
; ]