src/vs/editor/common/viewModel/viewModelImpl.ts/ViewModel/deduceModelPositionRelativeToViewPosition
class ViewModel:	public deduceModelPositionRelativeToViewPosition(viewAnchorPosition: Position, deltaOffset: number, lineFeedCnt: number): Position {
		const modelAnchor = this.coordinatesConverter.convertViewPositionToModelPosition(viewAnchorPosition);
		if (this.model.getEOL().length === 2) {
			// This model uses CRLF, so the delta must take that into account
			if (deltaOffset < 0) {
				deltaOffset -= lineFeedCnt;
			} else {
				deltaOffset += lineFeedCnt;
			}
		}

		const modelAnchorOffset = this.model.getOffsetAt(modelAnchor);
		const resultOffset = modelAnchorOffset + deltaOffset;
		return this.model.getPositionAt(resultOffset);
	}