calendar

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1. // dates.hl — plain date / text helpers shared by the server (events.hl) and the month view in the browser.
2. // No plugins, no Date (hl:time has no time zones): dates are 'YYYY-MM-DD' texts, times 'HH:MM'.
4. static isText = (v) => { return v != null && hlTypeName(v) == 'String' }
6. static digitsAt = (s, at, n) => {
7. if (s.length < at + n) { return false }
8. let i = at
9. while (i < at + n) {
10. let c = s.charCodeAt(i)
11. if (c < 48 || c > 57) { return false }
12. i = i + 1
13. }
14. return true
15. }
17. static leap = (y) => { return (y % 4 == 0 && y % 100 != 0) || y % 400 == 0 }
18. static daysIn = (y, m) => {
19. if (m == 2) { return leap(y) ? 29 : 28 }
20. if (m == 4 || m == 6 || m == 9 || m == 11) { return 30 }
21. return 31
22. }
23. static pad = (n) => { return n < 10 ? '0' + n : '' + n }
25. // 'YYYY-MM-DD' that is a real day
26. static isDate = (s) => {
27. if (!isText(s) || s.length != 10 || s[4] != '-' || s[7] != '-') { return false }
28. if (!digitsAt(s, 0, 4) || !digitsAt(s, 5, 2) || !digitsAt(s, 8, 2)) { return false }
29. let y = toNumber(s.slice(0, 4))
30. let m = toNumber(s.slice(5, 7))
31. let d = toNumber(s.slice(8, 10))
32. return y >= 1 && m >= 1 && m <= 12 && d >= 1 && d <= daysIn(y, m)
33. }
34. // 'HH:MM'
35. static isTime = (s) => {
36. if (!isText(s) || s.length != 5 || s[2] != ':' || !digitsAt(s, 0, 2) || !digitsAt(s, 3, 2)) { return false }
37. return toNumber(s.slice(0, 2)) < 24 && toNumber(s.slice(3, 5)) < 60
38. }
39. static nextDay = (s) => {
40. let y = toNumber(s.slice(0, 4))
41. let m = toNumber(s.slice(5, 7))
42. let d = toNumber(s.slice(8, 10))
43. if (d < daysIn(y, m)) { return s.slice(0, 8) + pad(d + 1) }
44. if (m < 12) { return s.slice(0, 5) + pad(m + 1) + '-01' }
45. return pad(y) + '-01-01'
46. }
47. static prevDay = (s) => {
48. let y = toNumber(s.slice(0, 4))
49. let m = toNumber(s.slice(5, 7))
50. let d = toNumber(s.slice(8, 10))
51. if (d > 1) { return s.slice(0, 8) + pad(d - 1) }
52. if (m > 1) { return s.slice(0, 5) + pad(m - 1) + '-' + pad(daysIn(y, m - 1)) }
53. return pad(y - 1) + '-12-31'
54. }
55. // a time zone name from the browser: letters, digits and _ / + - only
56. static isZone = (s) => {
57. if (!isText(s) || s.length < 1 || s.length > 64) { return false }
58. let i = 0
59. while (i < s.length) {
60. let c = s.charCodeAt(i)
61. let ok = (c >= 48 && c <= 57) || (c >= 65 && c <= 90) || (c >= 97 && c <= 122) || c == 95 || c == 47 || c == 43 || c == 45
62. if (!ok) { return false }
63. i = i + 1
64. }
65. return true
66. }
67. // a < b for equal-format ISO texts (hybriel #2: no ordering on strings)
68. static before = (a, b) => {
69. let i = 0
70. while (i < a.length && i < b.length) {
71. let x = a.charCodeAt(i)
72. let y = b.charCodeAt(i)
73. if (x != y) { return x < y }
74. i = i + 1
75. }
76. return a.length < b.length
77. }