wcwidth.go 5.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173
  1. // Package wcwidth provides utilities for determining the column width of
  2. // characters when displayed on the terminal.
  3. package wcwidth
  4. import (
  5. "sort"
  6. "strings"
  7. "sync"
  8. )
  9. var (
  10. overrideMutex sync.RWMutex
  11. override = map[rune]int{}
  12. )
  13. // Taken from http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c (public domain)
  14. var combining = [][2]rune{
  15. {0x0300, 0x036F}, {0x0483, 0x0486}, {0x0488, 0x0489},
  16. {0x0591, 0x05BD}, {0x05BF, 0x05BF}, {0x05C1, 0x05C2},
  17. {0x05C4, 0x05C5}, {0x05C7, 0x05C7}, {0x0600, 0x0603},
  18. {0x0610, 0x0615}, {0x064B, 0x065E}, {0x0670, 0x0670},
  19. {0x06D6, 0x06E4}, {0x06E7, 0x06E8}, {0x06EA, 0x06ED},
  20. {0x070F, 0x070F}, {0x0711, 0x0711}, {0x0730, 0x074A},
  21. {0x07A6, 0x07B0}, {0x07EB, 0x07F3}, {0x0901, 0x0902},
  22. {0x093C, 0x093C}, {0x0941, 0x0948}, {0x094D, 0x094D},
  23. {0x0951, 0x0954}, {0x0962, 0x0963}, {0x0981, 0x0981},
  24. {0x09BC, 0x09BC}, {0x09C1, 0x09C4}, {0x09CD, 0x09CD},
  25. {0x09E2, 0x09E3}, {0x0A01, 0x0A02}, {0x0A3C, 0x0A3C},
  26. {0x0A41, 0x0A42}, {0x0A47, 0x0A48}, {0x0A4B, 0x0A4D},
  27. {0x0A70, 0x0A71}, {0x0A81, 0x0A82}, {0x0ABC, 0x0ABC},
  28. {0x0AC1, 0x0AC5}, {0x0AC7, 0x0AC8}, {0x0ACD, 0x0ACD},
  29. {0x0AE2, 0x0AE3}, {0x0B01, 0x0B01}, {0x0B3C, 0x0B3C},
  30. {0x0B3F, 0x0B3F}, {0x0B41, 0x0B43}, {0x0B4D, 0x0B4D},
  31. {0x0B56, 0x0B56}, {0x0B82, 0x0B82}, {0x0BC0, 0x0BC0},
  32. {0x0BCD, 0x0BCD}, {0x0C3E, 0x0C40}, {0x0C46, 0x0C48},
  33. {0x0C4A, 0x0C4D}, {0x0C55, 0x0C56}, {0x0CBC, 0x0CBC},
  34. {0x0CBF, 0x0CBF}, {0x0CC6, 0x0CC6}, {0x0CCC, 0x0CCD},
  35. {0x0CE2, 0x0CE3}, {0x0D41, 0x0D43}, {0x0D4D, 0x0D4D},
  36. {0x0DCA, 0x0DCA}, {0x0DD2, 0x0DD4}, {0x0DD6, 0x0DD6},
  37. {0x0E31, 0x0E31}, {0x0E34, 0x0E3A}, {0x0E47, 0x0E4E},
  38. {0x0EB1, 0x0EB1}, {0x0EB4, 0x0EB9}, {0x0EBB, 0x0EBC},
  39. {0x0EC8, 0x0ECD}, {0x0F18, 0x0F19}, {0x0F35, 0x0F35},
  40. {0x0F37, 0x0F37}, {0x0F39, 0x0F39}, {0x0F71, 0x0F7E},
  41. {0x0F80, 0x0F84}, {0x0F86, 0x0F87}, {0x0F90, 0x0F97},
  42. {0x0F99, 0x0FBC}, {0x0FC6, 0x0FC6}, {0x102D, 0x1030},
  43. {0x1032, 0x1032}, {0x1036, 0x1037}, {0x1039, 0x1039},
  44. {0x1058, 0x1059}, {0x1160, 0x11FF}, {0x135F, 0x135F},
  45. {0x1712, 0x1714}, {0x1732, 0x1734}, {0x1752, 0x1753},
  46. {0x1772, 0x1773}, {0x17B4, 0x17B5}, {0x17B7, 0x17BD},
  47. {0x17C6, 0x17C6}, {0x17C9, 0x17D3}, {0x17DD, 0x17DD},
  48. {0x180B, 0x180D}, {0x18A9, 0x18A9}, {0x1920, 0x1922},
  49. {0x1927, 0x1928}, {0x1932, 0x1932}, {0x1939, 0x193B},
  50. {0x1A17, 0x1A18}, {0x1B00, 0x1B03}, {0x1B34, 0x1B34},
  51. {0x1B36, 0x1B3A}, {0x1B3C, 0x1B3C}, {0x1B42, 0x1B42},
  52. {0x1B6B, 0x1B73}, {0x1DC0, 0x1DCA}, {0x1DFE, 0x1DFF},
  53. {0x200B, 0x200F}, {0x202A, 0x202E}, {0x2060, 0x2063},
  54. {0x206A, 0x206F}, {0x20D0, 0x20EF}, {0x302A, 0x302F},
  55. {0x3099, 0x309A}, {0xA806, 0xA806}, {0xA80B, 0xA80B},
  56. {0xA825, 0xA826}, {0xFB1E, 0xFB1E}, {0xFE00, 0xFE0F},
  57. {0xFE20, 0xFE23}, {0xFEFF, 0xFEFF}, {0xFFF9, 0xFFFB},
  58. {0x10A01, 0x10A03}, {0x10A05, 0x10A06}, {0x10A0C, 0x10A0F},
  59. {0x10A38, 0x10A3A}, {0x10A3F, 0x10A3F}, {0x1D167, 0x1D169},
  60. {0x1D173, 0x1D182}, {0x1D185, 0x1D18B}, {0x1D1AA, 0x1D1AD},
  61. {0x1D242, 0x1D244}, {0xE0001, 0xE0001}, {0xE0020, 0xE007F},
  62. {0xE0100, 0xE01EF},
  63. }
  64. func isCombining(r rune) bool {
  65. n := len(combining)
  66. i := sort.Search(n, func(i int) bool { return r <= combining[i][1] })
  67. return i < n && r >= combining[i][0]
  68. }
  69. // OfRune returns the column width of a rune.
  70. func OfRune(r rune) int {
  71. if w, ok := getOverride(r); ok {
  72. return w
  73. }
  74. if r == 0 ||
  75. r < 32 || (0x7f <= r && r < 0xa0) || // Control character
  76. isCombining(r) {
  77. return 0
  78. }
  79. if r >= 0x1100 &&
  80. (r <= 0x115f || /* Hangul Jamo init. consonants */
  81. r == 0x2329 || r == 0x232a ||
  82. (r >= 0x2e80 && r <= 0xa4cf &&
  83. r != 0x303f) || /* CJK ... Yi */
  84. (r >= 0xac00 && r <= 0xd7a3) || /* Hangul Syllables */
  85. (r >= 0xf900 && r <= 0xfaff) || /* CJK Compatibility Ideographs */
  86. (r >= 0xfe10 && r <= 0xfe19) || /* Vertical forms */
  87. (r >= 0xfe30 && r <= 0xfe6f) || /* CJK Compatibility Forms */
  88. (r >= 0xff00 && r <= 0xff60) || /* Fullwidth Forms */
  89. (r >= 0xffe0 && r <= 0xffe6) || /* Fullwidth Forms */
  90. (r >= 0x20000 && r <= 0x2fffd) || /* CJK Extensions */
  91. (r >= 0x30000 && r <= 0x3fffd) || /* Reserved for historical Chinese scripts */
  92. (r >= 0x1f300 && r <= 0x1f6ff)) { // Miscellaneous Symbols and Pictographs ... Geometric Shapes Extended
  93. return 2
  94. }
  95. return 1
  96. }
  97. func getOverride(r rune) (int, bool) {
  98. overrideMutex.RLock()
  99. defer overrideMutex.RUnlock()
  100. w, ok := override[r]
  101. return w, ok
  102. }
  103. // Override overrides the column width of a rune to be a specific non-negative
  104. // value. If w < 0, it removes the override.
  105. func Override(r rune, w int) {
  106. if w < 0 {
  107. Unoverride(r)
  108. return
  109. }
  110. overrideMutex.Lock()
  111. defer overrideMutex.Unlock()
  112. override[r] = w
  113. }
  114. // Unoverride removes the column width override of a rune.
  115. func Unoverride(r rune) {
  116. overrideMutex.Lock()
  117. defer overrideMutex.Unlock()
  118. delete(override, r)
  119. }
  120. // Of returns the column width of a string, assuming no soft line breaks.
  121. func Of(s string) (w int) {
  122. for _, r := range s {
  123. w += OfRune(r)
  124. }
  125. return
  126. }
  127. // Trim trims the string s so that it has a column width of at most wmax.
  128. func Trim(s string, wmax int) string {
  129. w := 0
  130. for i, r := range s {
  131. w += OfRune(r)
  132. if w > wmax {
  133. return s[:i]
  134. }
  135. }
  136. return s
  137. }
  138. // Force forces the string s to the given column width by trimming and padding.
  139. func Force(s string, width int) string {
  140. w := 0
  141. for i, r := range s {
  142. w0 := OfRune(r)
  143. w += w0
  144. if w > width {
  145. w -= w0
  146. s = s[:i]
  147. break
  148. }
  149. }
  150. return s + strings.Repeat(" ", width-w)
  151. }
  152. // TrimEachLine trims each line of s so that it is no wider than the specified
  153. // width.
  154. func TrimEachLine(s string, width int) string {
  155. lines := strings.Split(s, "\n")
  156. for i := range lines {
  157. lines[i] = Trim(lines[i], width)
  158. }
  159. return strings.Join(lines, "\n")
  160. }