.flatMap(previousAuthorName => {
if (previousAuthorName === currentCommit.authorName) {
const currentCommitsByAuthor = previousGroup[1];
const index = accumulator.indexOf(previousGroup);
return new Some(accumulator.set(index, [ previousAuthorName, currentCommitsByAuthor.push(currentCommit) ]))
} else {
return None;
}
})
(tByAccount: List<ITransactionRecord>)=>{
return tByAccount.update(tByAccount.indexOf(originalTransaction),
(v)=>modifiedTransaction);
}
return state.update("notebook", (notebook: ImmutableNotebook) => {
const cellOrder: List<CellId> = notebook.get("cellOrder", List());
const index = cellOrder.indexOf(id);
return insertCellAt(notebook, cell, cellId, index);
});