48 lines
1.3 KiB
JavaScript
48 lines
1.3 KiB
JavaScript
export function findExpandedKeys() {
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var prev = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
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var next = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
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var prevLen = prev.length;
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var nextLen = next.length;
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if (Math.abs(prevLen - nextLen) !== 1) {
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return {
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add: false,
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key: null
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};
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}
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function find(shorter, longer) {
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var cache = new Map();
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shorter.forEach(function (key) {
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cache.set(key, true);
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});
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var keys = longer.filter(function (key) {
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return !cache.has(key);
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});
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return keys.length === 1 ? keys[0] : null;
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}
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if (prevLen < nextLen) {
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return {
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add: true,
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key: find(prev, next)
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};
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}
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return {
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add: false,
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key: find(next, prev)
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};
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}
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export function getExpandRange(shorter, longer, key) {
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var shorterStartIndex = shorter.findIndex(function (data) {
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return data.key === key;
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});
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var shorterEndNode = shorter[shorterStartIndex + 1];
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var longerStartIndex = longer.findIndex(function (data) {
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return data.key === key;
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});
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if (shorterEndNode) {
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var longerEndIndex = longer.findIndex(function (data) {
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return data.key === shorterEndNode.key;
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});
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return longer.slice(longerStartIndex + 1, longerEndIndex);
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}
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return longer.slice(longerStartIndex + 1);
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} |