feat: div_ceil

README.md

@@ -9,13 +9,13 @@ Put this into your Nargo.toml.
 If you are using Noir:
 
 ```toml
-nodash = { git = "https://github.com/olehmisar/nodash/", tag = "noir-v0.34.1" }
+nodash = { git = "https://github.com/olehmisar/nodash/", tag = "v0.35.0" }
 ```
 
 If you are using Aztec:
 
 ```toml
-nodash = { git = "https://github.com/olehmisar/nodash/", tag = "aztec-v0.54.0" }
+nodash = { git = "https://github.com/olehmisar/nodash/", tag = "aztec-v0.55.0" }
 ```
 
 ## Docs
@@ -44,6 +44,14 @@ assert(clamp(4 as u64, 1 as u64, 3 as u64) == 3 as u64);
 assert(clamp(2 as u64, 1 as u64, 3 as u64) == 2 as u64);
 ```
 
+### `div_ceil`
+
+```rs
+use nodash::div_ceil;
+
+assert(div_ceil(10 as u64, 3) == 4);
+```
+
 ### `solidity::encode_with_selector`
 
 Equivalent to `abi.encodeWithSelector` in Solidity.

src/lib.nr

@@ -3,7 +3,7 @@ mod solidity;
 mod string;
 
 pub use string::to_hex_string_bytes;
-pub use math::{clamp, sqrt::sqrt};
+pub use math::{clamp, div_ceil, sqrt::sqrt};
 
 pub fn array_concat<T, let L1: u32, let L2: u32>(a: [T; L1], b: [T; L2]) -> [T; L1 + L2] {
     let mut result = [a[0]; L1 + L2];

src/math.nr

@@ -1,4 +1,8 @@
 mod sqrt;
+mod numeric;
+
+use std::{ops::{Add, Div, Rem}, cmp::Eq};
+use numeric::Numeric;
 
 pub fn clamp<T>(x: T, min: T, max: T) -> T where T: Ord {
     if (x < min) {
@@ -10,8 +14,17 @@ pub fn clamp<T>(x: T, min: T, max: T) -> T where T: Ord {
     }
 }
 
-mod clamp_tests {
-    use crate::math::clamp;
+pub fn div_ceil<T>(a: T, b: T) -> T where T: Add + Div + Rem + Eq + Numeric {
+    let q = a / b;
+    if (a % b == T::zero()) {
+        q
+    } else {
+        q + T::one()
+    }
+}
+
+mod math_tests {
+    use crate::math::{clamp, div_ceil};
 
     #[test]
     fn test_clamp() {
@@ -22,4 +35,16 @@ mod clamp_tests {
         // if in range, return value
         assert(clamp(2 as u64, 1 as u64, 3 as u64) == 2 as u64);
     }
+
+    #[test]
+    fn test_div_ceil() {
+        assert(div_ceil(1 as u64, 2) == 1);
+        assert(div_ceil(2 as u64, 2) == 1);
+        assert(div_ceil(3 as u64, 2) == 2);
+        assert(div_ceil(4 as u64, 2) == 2);
+        assert(div_ceil(5 as u64, 2) == 3);
+        assert(div_ceil(1337 as u64, 19) == 71);
+        assert(div_ceil(1337 as u64, 7) == 191);
+        assert(div_ceil(10 as u64, 3) == 4);
+    }
 }

src/math/numeric.nr

@@ -0,0 +1,50 @@
+// TODO: remove this trait if it is implemented in Noir std lib.
+trait Numeric {
+    fn zero() -> Self;
+    fn one() -> Self;
+}
+
+impl Numeric for u8 {
+    fn zero() -> Self {
+        0
+    }
+    fn one() -> Self {
+        1
+    }
+}
+
+impl Numeric for u16 {
+    fn zero() -> Self {
+        0
+    }
+    fn one() -> Self {
+        1
+    }
+}
+
+impl Numeric for u32 {
+    fn zero() -> Self {
+        0
+    }
+    fn one() -> Self {
+        1
+    }
+}
+
+impl Numeric for u64 {
+    fn zero() -> Self {
+        0
+    }
+    fn one() -> Self {
+        1
+    }
+}
+
+impl Numeric for U128 {
+    fn zero() -> Self {
+        U128::from_integer(0)
+    }
+    fn one() -> Self {
+        U128::from_integer(1)
+    }
+}

src/math/sqrt.nr

@@ -1,4 +1,5 @@
 use std::{ops::{Mul, Div, Add}, cmp::Ord};
+use crate::math::numeric::Numeric;
 
 // TODO: check if this is correct
 pub fn sqrt<T>(value: T) -> T where T: Numeric + Mul + Ord + Add + Div {
@@ -39,48 +40,6 @@ unconstrained fn sqrt_unconstrained<T>(value: T) -> T where T: Numeric + Ord + A
     }
 }
 
-// TODO: remove this trait if it is implemented in Noir std lib.
-trait Numeric {
-    fn zero() -> Self;
-    fn one() -> Self;
-}
-
-impl Numeric for u8 {
-    fn zero() -> Self {
-        0
-    }
-    fn one() -> Self {
-        1
-    }
-}
-
-impl Numeric for u32 {
-    fn zero() -> Self {
-        0
-    }
-    fn one() -> Self {
-        1
-    }
-}
-
-impl Numeric for u64 {
-    fn zero() -> Self {
-        0
-    }
-    fn one() -> Self {
-        1
-    }
-}
-
-impl Numeric for U128 {
-    fn zero() -> Self {
-        U128::from_integer(0)
-    }
-    fn one() -> Self {
-        U128::from_integer(1)
-    }
-}
-
 mod sqrt_tests {
     use crate::math::sqrt::sqrt;