code-fenced.js 4.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236
  1. 'use strict';
  2. var trim = require('trim-trailing-lines');
  3. module.exports = fencedCode;
  4. var C_NEWLINE = '\n';
  5. var C_TAB = '\t';
  6. var C_SPACE = ' ';
  7. var C_TILDE = '~';
  8. var C_TICK = '`';
  9. var MIN_FENCE_COUNT = 3;
  10. var CODE_INDENT_COUNT = 4;
  11. function fencedCode(eat, value, silent) {
  12. var self = this;
  13. var settings = self.options;
  14. var length = value.length + 1;
  15. var index = 0;
  16. var subvalue = '';
  17. var fenceCount;
  18. var marker;
  19. var character;
  20. var flag;
  21. var queue;
  22. var content;
  23. var exdentedContent;
  24. var closing;
  25. var exdentedClosing;
  26. var indent;
  27. var now;
  28. if (!settings.gfm) {
  29. return;
  30. }
  31. /* Eat initial spacing. */
  32. while (index < length) {
  33. character = value.charAt(index);
  34. if (character !== C_SPACE && character !== C_TAB) {
  35. break;
  36. }
  37. subvalue += character;
  38. index++;
  39. }
  40. indent = index;
  41. /* Eat the fence. */
  42. character = value.charAt(index);
  43. if (character !== C_TILDE && character !== C_TICK) {
  44. return;
  45. }
  46. index++;
  47. marker = character;
  48. fenceCount = 1;
  49. subvalue += character;
  50. while (index < length) {
  51. character = value.charAt(index);
  52. if (character !== marker) {
  53. break;
  54. }
  55. subvalue += character;
  56. fenceCount++;
  57. index++;
  58. }
  59. if (fenceCount < MIN_FENCE_COUNT) {
  60. return;
  61. }
  62. /* Eat spacing before flag. */
  63. while (index < length) {
  64. character = value.charAt(index);
  65. if (character !== C_SPACE && character !== C_TAB) {
  66. break;
  67. }
  68. subvalue += character;
  69. index++;
  70. }
  71. /* Eat flag. */
  72. flag = '';
  73. queue = '';
  74. while (index < length) {
  75. character = value.charAt(index);
  76. if (
  77. character === C_NEWLINE ||
  78. character === C_TILDE ||
  79. character === C_TICK
  80. ) {
  81. break;
  82. }
  83. if (character === C_SPACE || character === C_TAB) {
  84. queue += character;
  85. } else {
  86. flag += queue + character;
  87. queue = '';
  88. }
  89. index++;
  90. }
  91. character = value.charAt(index);
  92. if (character && character !== C_NEWLINE) {
  93. return;
  94. }
  95. if (silent) {
  96. return true;
  97. }
  98. now = eat.now();
  99. now.column += subvalue.length;
  100. now.offset += subvalue.length;
  101. subvalue += flag;
  102. flag = self.decode.raw(self.unescape(flag), now);
  103. if (queue) {
  104. subvalue += queue;
  105. }
  106. queue = '';
  107. closing = '';
  108. exdentedClosing = '';
  109. content = '';
  110. exdentedContent = '';
  111. /* Eat content. */
  112. while (index < length) {
  113. character = value.charAt(index);
  114. content += closing;
  115. exdentedContent += exdentedClosing;
  116. closing = '';
  117. exdentedClosing = '';
  118. if (character !== C_NEWLINE) {
  119. content += character;
  120. exdentedClosing += character;
  121. index++;
  122. continue;
  123. }
  124. /* Add the newline to `subvalue` if its the first
  125. * character. Otherwise, add it to the `closing`
  126. * queue. */
  127. if (content) {
  128. closing += character;
  129. exdentedClosing += character;
  130. } else {
  131. subvalue += character;
  132. }
  133. queue = '';
  134. index++;
  135. while (index < length) {
  136. character = value.charAt(index);
  137. if (character !== C_SPACE) {
  138. break;
  139. }
  140. queue += character;
  141. index++;
  142. }
  143. closing += queue;
  144. exdentedClosing += queue.slice(indent);
  145. if (queue.length >= CODE_INDENT_COUNT) {
  146. continue;
  147. }
  148. queue = '';
  149. while (index < length) {
  150. character = value.charAt(index);
  151. if (character !== marker) {
  152. break;
  153. }
  154. queue += character;
  155. index++;
  156. }
  157. closing += queue;
  158. exdentedClosing += queue;
  159. if (queue.length < fenceCount) {
  160. continue;
  161. }
  162. queue = '';
  163. while (index < length) {
  164. character = value.charAt(index);
  165. if (character !== C_SPACE && character !== C_TAB) {
  166. break;
  167. }
  168. closing += character;
  169. exdentedClosing += character;
  170. index++;
  171. }
  172. if (!character || character === C_NEWLINE) {
  173. break;
  174. }
  175. }
  176. subvalue += content + closing;
  177. return eat(subvalue)({
  178. type: 'code',
  179. lang: flag || null,
  180. value: trim(exdentedContent)
  181. });
  182. }