Data commit

Task/Test-integerness/Nim/test-integerness.nim

@@ -0,0 +1,31 @@
+import complex, rationals, math, fenv, sugar
+
+func isInteger[T: Complex | Rational | SomeNumber](x: T; tolerance = 0f64): bool =
+  when T is Complex:
+    x.im == 0 and x.re.isInteger
+  elif T is Rational:
+    x.dup(reduce).den == 1
+  elif T is SomeFloat:
+    ceil(x) - x <= tolerance
+  elif T is SomeInteger:
+    true
+
+# Floats.
+assert not NaN.isInteger
+assert not INF.isInteger      # Indeed, "ceil(INF) - INF" is NaN.
+assert not (-5e-2).isInteger
+assert (-2.1e120).isInteger
+assert 25.0.isInteger
+assert not 24.999999.isInteger
+assert 24.999999.isInteger(tolerance = 0.00001)
+assert not (1f64 + epsilon(float64)).isInteger
+assert not (1f32 - epsilon(float32)).isInteger
+# Rationals.
+assert not (5 // 3).isInteger
+assert (9 // 3).isInteger
+assert (-143 // 13).isInteger
+# Unsigned integers.
+assert 3u.isInteger
+# Complex numbers.
+assert not (1.0 + im 1.0).isInteger
+assert (5.0 + im 0.0).isInteger