Result is rational(Number)which should be preferred.
When Number is an integer, Result is a rational with denominator 1.
When Number is already a rational, Result is identical to Number.
When Number is a float, Result is a rational whose value is exactly equal to the value of the floating-point number. Since floats are usually approximations of the intended value, the results may look unintuitive and have unnecessarily large numerators and denominators. Use rationalize/2 to produce the most compact rational that still converts back into the original float. rational/2 is usually faster than rationalize/2.
Bounded reals cannot be converted to rationals.
In coroutining mode, if Number is uninstantiated, the call to rational/2 is delayed until this variable is instantiated.
Success: rational(25, 25_1). rational(1.5, 3_2). rational(3_4,3_4). rational(9_12,3_4). rational(-6, Result). (gives Result = -6_1) rational(0.1, Result). (gives Result = 3602879701896397_36028797018963968) Fail: rational(1, 2_1). Error: rational(A, 1_3). (Error 4). rational(3, 3). (Error 5). rational(1, r). (Error 24). rational(4 + 2, 6_1). (Error 24). rational(0.9__1.1, X). (Error 141).