message: Fix performance bug in ex-command parser
diff: @@ -7,10 +7,12 @@ export const bangParser: Parser<boolean> = string('!')
  .map((bang) => bang !== undefined);
  export function nameAbbrevParser(abbrev: string, rest: string): Parser<string> {
  - const possibleNames = [...Array(rest.length + 1).keys()]
  + const suffixes = [...Array(rest.length + 1).keys()]
  .reverse()
  - .map((idx) => abbrev + rest.substring(0, idx));
  - return alt(...possibleNames.map(string));
  + .map((idx) => rest.substring(0, idx));
  + return string(abbrev)
  + .then(alt(...suffixes.map(string)))
  + .map((suffix) => abbrev + suffix);
  }
  // TODO: `:help cmdline-special`
  