index.js 1.1 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152
  1. 'use strict'
  2. exports.parse = parse
  3. exports.stringify = stringify
  4. var comma = ','
  5. var space = ' '
  6. var empty = ''
  7. // Parse comma-separated tokens to an array.
  8. function parse(value) {
  9. var values = []
  10. var input = String(value || empty)
  11. var index = input.indexOf(comma)
  12. var lastIndex = 0
  13. var end = false
  14. var val
  15. while (!end) {
  16. if (index === -1) {
  17. index = input.length
  18. end = true
  19. }
  20. val = input.slice(lastIndex, index).trim()
  21. if (val || !end) {
  22. values.push(val)
  23. }
  24. lastIndex = index + 1
  25. index = input.indexOf(comma, lastIndex)
  26. }
  27. return values
  28. }
  29. // Compile an array to comma-separated tokens.
  30. // `options.padLeft` (default: `true`) pads a space left of each token, and
  31. // `options.padRight` (default: `false`) pads a space to the right of each token.
  32. function stringify(values, options) {
  33. var settings = options || {}
  34. var left = settings.padLeft === false ? empty : space
  35. var right = settings.padRight ? space : empty
  36. // Ensure the last empty entry is seen.
  37. if (values[values.length - 1] === empty) {
  38. values = values.concat(empty)
  39. }
  40. return values.join(right + comma + left).trim()
  41. }