diffUtil.js 1.3 KB

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  1. export function findExpandedKeys() {
  2. var prev = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
  3. var next = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
  4. var prevLen = prev.length;
  5. var nextLen = next.length;
  6. if (Math.abs(prevLen - nextLen) !== 1) {
  7. return {
  8. add: false,
  9. key: null
  10. };
  11. }
  12. function find(shorter, longer) {
  13. var cache = new Map();
  14. shorter.forEach(function (key) {
  15. cache.set(key, true);
  16. });
  17. var keys = longer.filter(function (key) {
  18. return !cache.has(key);
  19. });
  20. return keys.length === 1 ? keys[0] : null;
  21. }
  22. if (prevLen < nextLen) {
  23. return {
  24. add: true,
  25. key: find(prev, next)
  26. };
  27. }
  28. return {
  29. add: false,
  30. key: find(next, prev)
  31. };
  32. }
  33. export function getExpandRange(shorter, longer, key) {
  34. var shorterStartIndex = shorter.findIndex(function (data) {
  35. return data.key === key;
  36. });
  37. var shorterEndNode = shorter[shorterStartIndex + 1];
  38. var longerStartIndex = longer.findIndex(function (data) {
  39. return data.key === key;
  40. });
  41. if (shorterEndNode) {
  42. var longerEndIndex = longer.findIndex(function (data) {
  43. return data.key === shorterEndNode.key;
  44. });
  45. return longer.slice(longerStartIndex + 1, longerEndIndex);
  46. }
  47. return longer.slice(longerStartIndex + 1);
  48. }