From da54010cf25b7168e561ff8142b4a0f80c5d53ec Mon Sep 17 00:00:00 2001
From: flip111 <flip101@gmail.com>
Date: Sun, 8 Oct 2023 23:54:05 +0200
Subject: [PATCH] Add single bit functions

---
 src/Data/Int/Bits.js   | 33 ++++++++++++++++++++++++++++++++
 src/Data/Int/Bits.purs | 43 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)

diff --git a/src/Data/Int/Bits.js b/src/Data/Int/Bits.js
index 49bbaff..7677ddc 100644
--- a/src/Data/Int/Bits.js
+++ b/src/Data/Int/Bits.js
@@ -46,3 +46,36 @@ export const complement = function (n) {
   /* jshint bitwise: false */
   return ~n;
 };
+
+export const zeroBits = 0;
+
+export const bit = function (n) {
+  return function (pos) {
+    return (1 << pos);
+  }
+};
+
+export const setBit = function (n) {
+  return function (pos) {
+    return n | (1 << pos);
+  }
+};
+
+export const clearBit = function (n) {
+  return function (pos) {
+    const mask = ~(1 << pos);
+    return n & mask;
+  }
+};
+
+export const complementBit = function (n) {
+  return function (pos) {
+    return n ^ (1 << pos);
+  }
+};
+
+export const testBit = function (n) {
+  return function (pos) {
+    return (n & (1 << pos)) === 0 ? 0 : 1;
+  }
+};
diff --git a/src/Data/Int/Bits.purs b/src/Data/Int/Bits.purs
index d1b4715..c4412c3 100644
--- a/src/Data/Int/Bits.purs
+++ b/src/Data/Int/Bits.purs
@@ -7,6 +7,12 @@ module Data.Int.Bits
   , shr
   , zshr
   , complement
+  , zeroBits
+  , bit
+  , setBit
+  , clearBit
+  , complementBit
+  , testBit
   ) where
 
 -- | Bitwise AND.
@@ -35,3 +41,40 @@ foreign import zshr :: Int -> Int -> Int
 
 -- | Bitwise NOT.
 foreign import complement :: Int -> Int
+
+-- | zeroBits is the value with all bits unset.
+zeroBits :: Int
+zeroBits = 0
+
+-- | bit i is a value with the i'th bit set and all other bits clear.
+foreign import bit :: Int -> Int
+
+-- | Set a bit
+-- |
+-- | ```purescript
+-- | setBit 0 1 == 2
+-- | ```
+foreign import setBit :: Int -> Int -> Int
+
+-- | Clear a bit
+-- |
+-- | ```purescript
+-- | clearBit 7 1 == 5
+-- | ```
+foreign import clearBit :: Int -> Int -> Int 
+
+-- | XOR a bit
+-- |
+-- | ```purescript
+-- | complementBit 7 1 == 5
+-- | complementBit 0 1 == 2
+-- | ```
+foreign import complementBit :: Int -> Int -> Int 
+
+-- | Test a bit
+-- |
+-- | ```purescript
+-- | testBit 0 1 == false
+-- | testBit 7 1 == true
+-- | ```
+foreign import testBit :: Int -> Int -> Boolean