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53 lines
1.8 KiB
53 lines
1.8 KiB
import {Fragment} from "./fragment"
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export function findDiffStart(a: Fragment, b: Fragment, pos: number): number | null {
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for (let i = 0;; i++) {
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if (i == a.childCount || i == b.childCount)
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return a.childCount == b.childCount ? null : pos
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let childA = a.child(i), childB = b.child(i)
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if (childA == childB) { pos += childA.nodeSize; continue }
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if (!childA.sameMarkup(childB)) return pos
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if (childA.isText && childA.text != childB.text) {
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for (let j = 0; childA.text![j] == childB.text![j]; j++)
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pos++
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return pos
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}
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if (childA.content.size || childB.content.size) {
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let inner = findDiffStart(childA.content, childB.content, pos + 1)
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if (inner != null) return inner
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}
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pos += childA.nodeSize
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}
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}
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export function findDiffEnd(a: Fragment, b: Fragment, posA: number, posB: number): {a: number, b: number} | null {
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for (let iA = a.childCount, iB = b.childCount;;) {
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if (iA == 0 || iB == 0)
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return iA == iB ? null : {a: posA, b: posB}
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let childA = a.child(--iA), childB = b.child(--iB), size = childA.nodeSize
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if (childA == childB) {
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posA -= size; posB -= size
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continue
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}
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if (!childA.sameMarkup(childB)) return {a: posA, b: posB}
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if (childA.isText && childA.text != childB.text) {
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let same = 0, minSize = Math.min(childA.text!.length, childB.text!.length)
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while (same < minSize && childA.text![childA.text!.length - same - 1] == childB.text![childB.text!.length - same - 1]) {
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same++; posA--; posB--
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}
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return {a: posA, b: posB}
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}
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if (childA.content.size || childB.content.size) {
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let inner = findDiffEnd(childA.content, childB.content, posA - 1, posB - 1)
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if (inner) return inner
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}
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posA -= size; posB -= size
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}
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}
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