handwrite several classes of tailwindcss in unocss

uno.config.ts

/* eslint-disable no-useless-escape */
// uno.config.ts
import { defineConfig } from 'unocss'

function spaceToRem(space: string) {
  const num = parseInt(space)
  if (!isNaN(num)) {
    return `${num * 0.25}rem`
  } 
  return space
} 

export default defineConfig({
  presets: [],
  rules: [
    [/^m-\[([^\[\]]+)\]$/, ([, val]) => ({ margin: val })],
    [/^mt-\[([^\[\]]+)\]$/, ([, val]) => ({ 'margin-top': val })],
    [/^mb-\[([^\[\]]+)\]$/, ([, val]) => ({ 'margin-bottom': val })],
    [/^my-\[([^\[\]]+)\]$/, ([, val]) => ({ 'margin-top': val, 'margin-bottom': val })],
    [/^ml-\[([^\[\]]+)\]$/, ([, val]) => ({ 'margin-left': val })],
    [/^mr-\[([^\[\]]+)\]$/, ([, val]) => ({ 'margin-right': val })],
    [/^mx-\[([^\[\]]+)\]$/, ([, val]) => ({ 'margin-left': val, 'margin-right': val })],
    [/^gap-\[([^\[\]]+)\]$/, ([,val]) => ({gap: val})],

    [/^m-([\d]+)$/, ([,val]) => ({margin: spaceToRem(val)})],
    [/^mt-([\d]+)$/, ([,val]) => ({'margin-top': spaceToRem(val)})],
    [/^mb-([\d]+)$/, ([,val]) => ({'margin-bottom': spaceToRem(val)})],
    [/^ml-([\d]+)$/, ([,val]) => ({'margin-left': spaceToRem(val)})],
    [/^mr-([\d]+)$/, ([,val]) => ({'margin-right': spaceToRem(val)})],
    [/^mx-([\d]+)$/, ([,val]) => ({'margin-left': spaceToRem(val), 'margin-right': spaceToRem(val)})],
    [/^my-([\d]+)$/, ([,val]) => ({'margin-top': spaceToRem(val), 'margin-bottom': spaceToRem(val) })],
    [/^gap-([\d]+)$/, ([,val]) => ({gap: spaceToRem(val)})],

    ['flex', { display: 'flex' }],
    ['flex-col', {'flex-direction': 'column'}],
    ['flex-row', {'flex-direction': 'row'}],
  ]
})