1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62

import { Node } from './types/Node'
import { Parser, ParseText } from './types/Parser'

export const or = (parsers: Parser[]): Parser => {
  const { length } = parsers

  return (text, position, rootParser) => {
    for (let i = 0; i < length; i++) {
      const match = parsers[i](text, position, rootParser)

      if (match) {
        return match
      }
    }

    return null
  }
}

export const regexp = (
  pattern: RegExp,
  callback: (
    match: string[],
    text: string,
    position: number,
    parseText: ParseText
  ) => [Node, number] | null
): Parser => (text, position, parseText) => {
  const match = text.substring(position).match(pattern)

  if (!match) {
    return null
  }

  return callback(match, text, position, parseText)
}

export const explicit = (parser: Parser): Parser => (
  text,
  position,
  parseText
) => {
  const prevChar = text.charAt(position - 1)

  if (prevChar && !prevChar.match(/\s/)) {
    return null
  }

  return parser(text, position, parseText)
}

export const topOfLine = (parser: Parser): Parser => (
  text,
  position,
  parseText
) => {
  if (position > 0 && text.charAt(position - 1) !== '\n') {
    return null
  }

  return parser(text, position, parseText)
}