message: update: improve method for determining one alphabet
diff: @@ -38,13 +38,7 @@ export let compareKeypressSequence = function(one: string[] | string[][], two: s
  );
  };
  - const isSingleAlpha = (s: string): boolean => {
  - if (s.length === 1 && (('a' <= s && s <= 'z') || ('A' <= s && s <= 'Z'))) {
  - return true;
  - } else {
  - return false;
  - }
  - };
  + const singleAlpha: RegExp = /^[a-zA-Z]$/;
  for (let i = 0, j = 0; i < one.length; i++, j++) {
  const left = one[i],
  @@ -64,10 +58,10 @@ export let compareKeypressSequence = function(one: string[] | string[][], two: s
  continue;
  }
  - if (left === '<alpha>' && isSingleAlpha(right)) {
  + if (left === '<alpha>' && singleAlpha.test(right)) {
  continue;
  }
  - if (right === '<alpha>' && isSingleAlpha(left)) {
  + if (right === '<alpha>' && singleAlpha.test(left)) {
  continue;
  }
  