Differentiating between left and right shift key

Question

I have a bad habit of using the shift key of the same side of the keyboard as the letter when tying uppercase letters. To type a D, for example, I press the left shift with my left pinky and d with my left index finger. It is better to use the right shift in combination with keys on the left hand side of the keyboard, and vise versa.

To get rid of this habit I would like to disable the combinations of either shift key with keys on the same side of the keyboard. I can map shift-d with <S-d>, but this applies to both shift keys. Is there a to apply only to the right hand shift key?

Answer 1

From the Vim FAQ 20.4. "I am not able to create a mapping for the key. What is wrong?":

1) First make sure, the key is passed correctly to Vim. To determine if this is the case, put Vim in Insert mode and then hit Ctrl-V (or Ctrl-Q if your Ctrl-V is remapped to the paste operation (e.g. on Windows if you are using the mswin.vim script file) followed by your key.

If nothing appears in the buffer (and assuming that you have 'showcmd' on, ^V remains displayed near the bottom right of the Vim screen), then Vim doesn't get your key correctly and there is nothing to be done, other than selecting a different key for your mapping or using GVim, which should recognise the key correctly.

On my setup issuing Ctrl-q+Left Shfit-d displays 'D', and issuing Ctrl-q+Right Shfit-d leads to the same result. So at least here Vim is unable to detect the difference.

But maybe you could use some other tool to aid you on this; for instance, on Windows you could try AutoHotkey with something like this:

#ifWinActive ahk_class Vim
LShift & d::MsgBox You pressed the wrong 'Shift'!
#ifWinActive

or to simple ignore the combination:

#ifWinActive ahk_class Vim
LShift & d::
#ifWinActive

Answer 2

For MacOS, this can be fairly easily accomplished using Karabiner-Elements and goku (better config language for karabiner). Here's what the relevant bit in my karabiner.edn that basically maps all those "bad" shift- combos to nothing looks like:

;; Modifiers spec for reference:
;; !  | means mandatory
;; #  | means optional
;; C  | left_command
;; T  | left_control
;; O  | left_option
;; S  | left_shift
;; F  | fn
;; Q  | right_command
;; W  | right_control
;; E  | right_option
;; R  | right_shift
;; P  | caps_lock
;; !! | mandatory command + control + optional + shift (hyper)
;; ## | optional any

             {:des   "mappings"
              :rules [
                      ;; help me get better at not typing shift key on same side of keyboard as key
                      ;; left side
                      [:!Sq []]
                      [:!Sw []]
                      [:!Se []]
                      [:!Sr []]
                      [:!St []]
                      [:!Sa []]
                      [:!Ss []]
                      [:!Sd []]
                      [:!Sf []]
                      [:!Sg []]
                      [:!Sz []]
                      [:!Sx []]
                      [:!Sc []]
                      [:!Sv []]
                      [:!Sb []]
                      [:!S1 []]
                      [:!S2 []]
                      [:!S3 []]
                      [:!S4 []]
                      [:!S5 []]
                      ;; right side
                      [:!Ry []]
                      [:!Ru []]
                      [:!Ri []]
                      [:!Ro []]
                      [:!Rp []]
                      [:!Rh []]
                      [:!Rj []]
                      [:!Rk []]
                      [:!Rl []]
                      [:!Rn []]
                      [:!Rm []]
                      [:!R6 []]
                      [:!R7 []]
                      [:!R8 []]
                      [:!R9 []]
                      [:!R0 []]
                      ]}

Useful links:

• karabiner examples: https://github.com/nikitavoloboev/dotfiles/blob/master/karabiner/karabiner.edn
• goku exmamples: https://github.com/yqrashawn/GokuRakuJoudo/blob/master/examples.org
• goku tutorial: https://github.com/yqrashawn/GokuRakuJoudo/blob/master/tutorial.md

For reference, here's my full karabiner.edn:

;; Modifiers spec:
;; !  | means mandatory
;; #  | means optional
;; C  | left_command
;; T  | left_control
;; O  | left_option
;; S  | left_shift
;; F  | fn
;; Q  | right_command
;; W  | right_control
;; E  | right_option
;; R  | right_shift
;; P  | caps_lock
;; !! | mandatory command + control + optional + shift (hyper)
;; ## | optional any
{
 :profiles
            {:Default {:default true
                    :sim     100
                    :delay   500
                    :alone   1000
                    :held    500}}

 :devices {:kinesis-keyboard [{:vendor_id 1523 :product_id 7}]}
            }

 :main      [
             {:des "simultaneous j k press to ESC" :rules [[[:j :k] :escape]]}
             {:des "simultaneous d f press to ctrl-space" :rules [[[:d :f]  {:key :spacebar :modi [:left_control]} ]]}
             {:des "swap end with left option" :rules [[:##end :left_option :kinesis-keyboard]]}
             {:des "swap control and command" :rules [[:##left_control :left_command :kinesis-keyboard]
                                                      [:##right_command :right_control :kinesis-keyboard]
                                                      [:##right_control :right_command :kinesis-keyboard]
                                                      ]}
             {:des "command left/right to opt left/right" :rules [
                                                      [:!Cleft_arrow {:key :left_arrow :modi [:left_option]}]
                                                      [:!Cright_arrow {:key :right_arrow :modi [:left_option]}]
                                                      ]}
             {:des "command backsapce to opt backspace" :rules [
                                                      [:!Cdelete_or_backspace {:key :delete_or_backspace :modi [:left_option]}]
                                                      [:!Qdelete_or_backspace {:key :delete_or_backspace :modi [:left_option]}]
                                                      ]}
             {:des "have home emit CTOS modifiers" :rules [[:##home {:key :left_command :modi [:left_command :left_control :left_option :left_shift]}]]}
             {:des "have caps_lock emit CTOS modifiers" :rules [[:##caps_lock {:key :left_command :modi [:left_command :left_control :left_option :left_shift]}]]}

             {:des   "mappings"
              :rules [
                      ;; help me get better at not typing shift key on same side of keyboard as key
                      ;; left side
                      [:!Sq []]
                      [:!Sw []]
                      [:!Se []]
                      [:!Sr []]
                      [:!St []]
                      [:!Sa []]
                      [:!Ss []]
                      [:!Sd []]
                      [:!Sf []]
                      [:!Sg []]
                      [:!Sz []]
                      [:!Sx []]
                      [:!Sc []]
                      [:!Sv []]
                      [:!Sb []]
                      [:!S1 []]
                      [:!S2 []]
                      [:!S3 []]
                      [:!S4 []]
                      [:!S5 []]
                      ;; right side
                      [:!Ry []]
                      [:!Ru []]
                      [:!Ri []]
                      [:!Ro []]
                      [:!Rp []]
                      [:!Rh []]
                      [:!Rj []]
                      [:!Rk []]
                      [:!Rl []]
                      [:!Rn []]
                      [:!Rm []]
                      [:!R6 []]
                      [:!R7 []]
                      [:!R8 []]
                      [:!R9 []]
                      [:!R0 []]
                      ]}
             ]
 }