config

#[...]

# Alt-tab
bindsym Mod1+tab exec ~/.config/sway/alttab.rb

#[...]

sway-sane-alt-tab.rb

#!/usr/bin/env ruby

def current_tag_focused_client_id
    `swaymsg -t get_tree | jq --arg active_workspace $(swaymsg -t get_tree | jq '[ .nodes[] | .nodes ] | flatten | map({id, name, focused: [ .nodes | map(.focused) | reduce .[] as $item (false; . or $item) ] | .[0] }) | .[] | select(.focused) | .id') '[ .nodes[] | .nodes ] | flatten | .[] | select(.id == ($active_workspace | tonumber)) | .nodes | .[] | [ select(.focused == true) ] | .[] | .id'`.to_i
end

def current_tag_unfocused_clients_ids
    `swaymsg -t get_tree | jq --arg active_workspace $(swaymsg -t get_tree | jq '[ .nodes[] | .nodes ] | flatten | map({id, name, focused: [ .nodes | map(.focused) | reduce .[] as $item (false; . or $item) ] | .[0] }) | .[] | select(.focused) | .id') '[ .nodes[] | .nodes ] | flatten | .[] | select(.id == ($active_workspace | tonumber)) | .nodes | .[] | [ select(.focused == false) ] | .[] | .id'`.split.map(&:to_i).sort
end

def focus_this_client( con_id )
    `swaymsg [con_id=#{con_id}] focus` unless con_id.nil?
end

def find_next_client_id( focused_client_id, unfocused_clients_ids )
    return focused_client_id if focused_client_id.nil? || unfocused_clients_ids.nil? || unfocused_clients_ids.empty?

    next_client_id = unfocused_clients_ids.find { |i| i > focused_client_id }
    next_client_id = unfocused_clients_ids.first if next_client_id.nil?

    next_client_id
end

focus_this_client( find_next_client_id( current_tag_focused_client_id, current_tag_unfocused_clients_ids ) )

I did the same thing but in bash, and it's lagging as hell :).

Did try bunch of switcher but can't find one just simply fast, switch windows on a focused workspace only, and switch on all kinds of windows.

Anyway your script lack of floating_nodes, I think you don't intend to use floating windows, yes?

And how about nested windows? I guess that's why my switcher is so lag :)