Function unitParse

Returns
    | {
        coefficient: any;
        error?: undefined;
        expr: Mul;
        parsed: boolean;
        type: any;
        unit: Expr;
    }
    | {
        coefficient?: undefined;
        error?: undefined;
        expr?: undefined;
        parsed: boolean;
        type: any;
        unit: Expr;
    }
    | {
        coefficient?: undefined;
        error: string;
        expr?: undefined;
        parsed: boolean;
        type?: undefined;
        unit?: undefined;
    }