Add rounding

README.md

@@ -171,6 +171,11 @@ type ModExmaple = Mod<87, 7>
 * [`Max`](#max)
 * [`Min`](#min)
 
+## Rounding Operations
+- [`Round`](#round)
+- [`Floor`](#floor)
+- [`Ceil`](#ceil)
+
 ## Other Checks
 ### Sign
 * [`IsPositive`](#ispositive)
@@ -514,7 +519,45 @@ type NormalExample3 = Min<10.1234, -5.111> // -5.111
 type UnionExample = Min<5|8|10, 7> // 5 | 7
 
 type NumberExample = Min<number, 7> // number
+```
+### `Round`
+Round the number to the nearest integer, rounding up if it equidistant.
+```ts
+type PositiveExample1 = Round<13> // 13
+type PositiveExample2 = Round<13.47> // 13
+type PositiveExample3 = Round<13.50> // 14
+type PositiveExample4 = Round<13.85> // 14
+
+type NegativeExample1 = Round<-8.21> // -8
+type NegativeExample2 = Round<-8.50> // -8
+type NegativeExample3 = Round<-8.94> // -9
+```
+### `Floor`
+Round the number to the closest integer less than or equal to the given number.
+```ts
+type PositiveExample1 = Floor<3> // 3
+type PositiveExample2 = Floor<3.31> // 3
+type PositiveExample3 = Floor<3.50> // 3
+type PositiveExample4 = Floor<3.99> // 3
+
+type NegativeExample1 = Floor<-6> // -6
+type NegativeExample2 = Floor<-6.50> // -7
+type NegativeExample3 = Floor<-6.92> // -7
+type NegativeExample4 = Floor<-7.11> // -8
+
+```
+### `Ceil`
+Round the number to the closest integer greater than or equal to the given number.
+```ts
+type PositiveExample1 = Ceil<70> // 70
+type PositiveExample2 = Ceil<70.12> // 71
+type PositiveExample3 = Ceil<70.50> // 71
+type PositiveExample4 = Ceil<70.88> // 71
 
+type NegativeExample1 = Ceil<-8> // -8
+type NegativeExample2 = Ceil<-8.21> // -8
+type NegativeExample3 = Ceil<-8.50> // -8
+type NegativeExample4 = Ceil<-8.94> // -8
 ```
 ### `IsPositive`
 Check if a numeric literal is positive.

src/Arithmetic/Number/Round.ts

@@ -0,0 +1,50 @@
+import type { Abs, IsNegative, Negate } from './Sign'
+import type { Gt, GtOrEq } from './Compare'
+import type { Multiply } from '../Multiplication/Multiply'
+import type { Subtract } from '../Subtraction/Subtract'
+import type { IsInt } from './IsInt'
+import type { Mod } from '../../Arithmetic/Division'
+import type { Add } from '../../Arithmetic/Addition'
+
+type TakeIntegerComponent<N extends number> = (
+    `${N}` extends `${infer I extends number}.${string}` ? I : N
+)
+
+/**
+ * Round the number to the nearest integer, rounding up if it equidistant.
+ *
+ * @param N - The number to round.
+ * @returns round(N) - The closest integer to the given number, rounding up if it is equidistant.
+ *
+ * @public
+*/
+export type Round<N extends number> = (
+    IsInt<N> extends 1 ? N : 
+        IsNegative<N> extends 1
+            ? Negate<Subtract<Gt<Multiply<Mod<Abs<N>, 1>, 10>, 5>, TakeIntegerComponent<N>>>
+            : Add<GtOrEq        <Multiply<Mod<    N , 1>, 10>, 5>, TakeIntegerComponent<N>>
+)
+
+/**
+ * Round the number to the closest integer less than or equal to the given number.
+ * 
+ * @param N - The number to round.
+ * @returns floor(N) - The closest integer less than or equal to the given number.
+ * 
+ * @public
+*/
+export type Floor<N extends number> = (
+    IsInt<N> extends 1 ? N : Negate<Subtract<IsNegative<N>, TakeIntegerComponent<N>>>
+)
+
+/**
+ * Round the number to the closest integer greater than or equal to the given number.
+ * 
+ * @param N - The number to round.
+ * @returns ceil(N) - The closest integer greater than or equal to the given number.
+ * 
+ * @public
+*/
+export type Ceil<N extends number> = (
+    IsInt<N> extends 1 ? N : Add<Floor<N>, 1>
+)

src/Arithmetic/Number/index.ts

@@ -6,4 +6,5 @@ export type { IsOdd, IsEven } from './Parity'
 export type { ToUnsignedFloat, ToSignedFloat } from './ToFloat'
 export type { ToSignedInt } from './ToInt'
 export type { IsInt, IsNotInt } from './IsInt'
-export type { Gt, Lt, Eq, GtOrEq, LtOrEq, Max, Min } from './Compare'
+export type { Gt, Lt, Eq, GtOrEq, LtOrEq, Max, Min } from './Compare'
+export type { Round, Floor, Ceil } from './Round'

src/index.ts

@@ -4,5 +4,5 @@ export type { Multiply } from './Arithmetic/Multiplication'
 export type { Divide, Mod } from './Arithmetic/Division'
 export type { Pow } from './Arithmetic/Exponentiation'
 export type { Negate, Abs, IsPositive, IsNegative, Compare, IsOdd, IsEven, IsInt, IsNotInt } from './Arithmetic/Number'
-export type { Gt, Lt, Eq, GtOrEq, LtOrEq, Max, Min } from './Arithmetic/Number'
+export type { Gt, Lt, Eq, GtOrEq, LtOrEq, Max, Min, Round, Floor, Ceil } from './Arithmetic/Number'
 export type { Bit, And, Or, Xor, Not } from './Arithmetic/Bit'