json-joy
Version:
Collection of libraries for building collaborative editing apps.
44 lines (43 loc) • 1.77 kB
JavaScript
import { OpStrDel, OpStrIns } from '../../json-patch/op';
export const xStrDel = (del, op) => {
if (op instanceof OpStrIns) {
const ins = op;
if (ins.pos > del.pos) {
const deleteLength = del.deleteLength();
return new OpStrIns(ins.path, op.pos - deleteLength, op.str);
}
return op;
}
if (op instanceof OpStrDel) {
const opLen = op.deleteLength();
const delLen = del.deleteLength();
const overlapLen1 = del.pos + delLen - op.pos;
const overlapLen2 = op.pos + opLen - del.pos;
if (del.pos <= op.pos && overlapLen1 > 0) {
const newLen = opLen - overlapLen1;
if (newLen <= 0)
return null;
if (typeof op.str === 'string')
return new OpStrDel(op.path, op.pos - (delLen - overlapLen1), op.str.substr(overlapLen1), undefined);
else
return new OpStrDel(op.path, op.pos - (delLen - overlapLen1), undefined, newLen);
}
else if (del.pos >= op.pos && overlapLen2 > 0) {
const newLen = del.pos - op.pos + Math.max(0, overlapLen2 - delLen);
if (newLen <= 0)
return null;
if (typeof op.str === 'string')
return new OpStrDel(op.path, op.pos, op.str.substr(0, newLen), undefined);
else
return new OpStrDel(op.path, op.pos, undefined, newLen);
}
else if (del.pos < op.pos) {
if (typeof op.str === 'string')
return new OpStrDel(op.path, op.pos - delLen, op.str, undefined);
else
return new OpStrDel(op.path, op.pos - delLen, undefined, op.len);
}
return op;
}
return op;
};