{
        # body
        redo
            if  ...;
        # tail
    }
    # post

# vs

    TOP:
        # body
        goto TOP
            if  ...;
        # tail
    # post

##</code><code>##

    {
        # body
        redo
            if  ...;
    }
    # post

# becomes:

    do {
        # body
    } until( ! ... );
    # post

##</code><code>##

# bare block "loop":

    {
        # head
        last
            if  ...;
        # body
    }
    # post

# vs goto:

    # top?
        # head
        goto END
            if  ...;
        # body
    END:
    # post

# vs if:

    # head
    if(  ! ...  ) {
        # body
    }
    # post

##</code><code>##

    {
        # top
        last
            if ...;
        # middle
        redo
            if ...;
        # tail
    }
    # post

    TOP:
        # top
        goto END
            if ...;
        # middle
        goto TOP
            if ...;
        # tail
    END:
    # post

##</code><code>##

LOOP: {
   try something;

   if (!success) {
      wait;
      redo;
   }
}

# becomes:

while( 1 ) {
    try something;

    last
        if  failed;
    sleep $seconds;
}

##</code><code>##

    while(  ! try_something()  ) {
        sleep $seconds;
    }