element-plus/packages/components/slider/src/useMarks.ts

import { computed } from 'vue'
import type { ISliderProps, Mark } from './slider.type'

export const useMarks = (props: ISliderProps) => {
  return computed(() => {
    if (!props.marks) {
      return []
    }

    const marksKeys = Object.keys(props.marks)
    return marksKeys
      .map(parseFloat)
      .sort((a, b) => a - b)
      .filter((point) => point <= props.max && point >= props.min)
      .map(
        (point): Mark => ({
          point,
          position: ((point - props.min) * 100) / (props.max - props.min),
          mark: props.marks[point],
        })
      )
  })
}