/// <summary>Gets the factors composing an expression.</summary> /// <param name="e">The expression whose factors should be returned.</param> /// <returns>A read-only span of the factors composing the expression.</returns> public static ReadOnlySpan <SymbolicExpression> GetFactors(ref SymbolicExpression e) => e.IsMultiplication() ? e.GetOperands() : MemoryMarshal.CreateReadOnlySpan(ref e, 1);