added mean, sum, sort

README.md

@@ -21,12 +21,15 @@ The following functions are supported:
 - [divide](#divide)
 - [floor](#floor)
 - [max](#max)
+- [mean](#mean)
 - [min](#min)
 - [multiply](#multiply)
 - [pow](#pow)
 - [remainder](#remainder)
 - [sign](#sign)
+- [sort](#sort)
 - [subtract](#subtract)
+- [sum](#sum)
 - [truncate](#truncate)
 
 ## install
@@ -56,6 +59,7 @@ abs("-10");
 ```
 
 ### add
+Add two numbers together.
 ```js
 import add from "preciso/add.js";
 
@@ -108,6 +112,20 @@ floor("-45.951267538761253765124376412365124736541263451265347126534761524376512
 "-46"
 ```
 
+### mean
+```js
+import mean from "preciso/mean.js";
+
+mean(["1", "10", "4"])
+"5"
+
+mean(["1", "2", "8"], { max_decimal_digits: 3 })
+"3.667"
+
+mean(["1", "2", "8"], { ellipsis: true })
+"3.666..."
+```
+
 ### max
 ```js
 import max from "preciso/min.js";
@@ -173,6 +191,19 @@ sign("-0.00");
 ""
 ```
 
+### sort
+```js
+import sort from "preciso/sort.js"
+
+// default is sorting in ascending order (smallest to greatest)
+sort(["1", "2", "3"])
+["1", "2", "3"]
+
+// sort in descending order from greatest to smallest
+sort(["1", "2", "3"], { direction: "descending" })
+["3", "2", "1"]
+```
+
 ### subtract
 ```js
 import subtract from "preciso/subtract.js";
@@ -181,6 +212,15 @@ subtract("10", "2.14"); // 10 - 2.14
 "7.86"
 ```
 
+### sum
+Similar to add, but can take an array of more than two numbers.
+```js
+import sum from "preciso/sum.js";
+
+sum(["1", "2", "3"])
+"6"
+```
+
 ### truncate
 ```js
 import truncate from "preciso/truncate.js";

mean.js

@@ -0,0 +1,15 @@
+const add = require("./add.js");
+const divide = require("./divide.js");
+
+function mean(nums, options) {
+  let count = 0;
+  let total = "0";
+  for (let num of nums) {
+    count++;
+    total = add(total, num);
+  }
+  return divide(total, count.toString(), options);
+}
+
+module.exports = mean;
+module.exports.default = mean;

package.json

@@ -25,6 +25,7 @@
     "long_multiplication.js",
     "long_subtraction.js",
     "max.js",
+    "mean.js",
     "min.js",
     "multiply.js",
     "pow.js",
@@ -36,10 +37,13 @@
     "round_last_decimal.js",
     "sign.js",
     "sign_nonzero.js",
+    "sort.js",
     "subtract.js",
+    "sum.js",
     "truncate.js"
   ],
   "scripts": {
+    "b": "npm run build",
     "build": "npx browserify preciso.js > preciso.min.js",
     "f": "npm run format",
     "format": "npx prettier --arrow-parens=avoid --print-width=160 --trailing-comma=none --write *.js *.ts",

preciso.js

@@ -11,6 +11,7 @@ const is_infinity = require("./is_infinity.js");
 const is_integer = require("./is_integer.js");
 const is_zero = require("./is_zero.js");
 
+const mean = require("./mean.js");
 const min = require("./min.js");
 const max = require("./max.js");
 const expand = require("./expand.js");
@@ -37,6 +38,10 @@ const pow_positive = require("./pow_positive.js");
 const sign = require("./sign.js");
 const sign_nonzero = require("./sign_nonzero.js");
 
+const sort = require("./sort.js");
+
+const sum = require("./sum.js");
+
 const truncate = require("./truncate.js");
 
 const module_exports = {
@@ -55,6 +60,7 @@ const module_exports = {
   is_integer,
   is_zero,
 
+  mean,
   min,
   max,
 
@@ -78,6 +84,10 @@ const module_exports = {
   sign,
   sign_nonzero,
 
+  sort,
+
+  sum,
+
   subtract,
   long_subtraction,
 

sort.js

@@ -0,0 +1,9 @@
+const compare = require("./compare");
+
+function sort(nums, { direction = "ascending" } = { direction: "ascending" }) {
+  const op = direction === "desc" || direction === "descending" ? "<" : ">";
+  return nums.sort((a, b) => (compare(a, b) === op ? 1 : -1));
+}
+
+module.exports = sort;
+module.exports.default = sort;

sum.js

@@ -0,0 +1,13 @@
+const add = require("./add.js");
+
+function sum(nums) {
+  let total = "0";
+  // using iterator protocol
+  for (let num of nums) {
+    total = add(total, num);
+  }
+  return total;
+}
+
+module.exports = sum;
+module.exports.default = sum;

test.js

@@ -13,6 +13,7 @@ const {
   is_infinity,
   is_integer,
   is_zero,
+  mean,
   min,
   max,
   expand,
@@ -26,10 +27,32 @@ const {
   remainder,
   round_last_decimal,
   sign,
+  sort,
+  sum,
   subtract,
   truncate
 } = preciso;
 
+test("sort", ({ eq }) => {
+  eq(sort(["1", "2", "3"]), ["1", "2", "3"]);
+  eq(sort(["1", "2", "3"], { direction: "descending" }), ["3", "2", "1"]);
+  const nums = ["0", "-10", "-10.213", "12e34", "-1e-424", "3123761254357621"];
+  eq(sort(nums), ["-10.213", "-10", "-1e-424", "0", "3123761254357621", "12e34"]);
+  eq(sort(nums, { direction: "descending" }), ["12e34", "3123761254357621", "0", "-1e-424", "-10", "-10.213"]);
+});
+
+test("sum", ({ eq }) => {
+  eq(sum(["1", "2", "3"]), "6");
+  eq(sum(["1", "2", "8"]), "11");
+});
+
+test("mean", ({ eq }) => {
+  eq(mean(["1", "10", "4"]), "5");
+  eq(mean(["-1", "2", "8"], { ellipsis: true }), "3");
+  eq(mean(["1", "2", "8"], { max_decimal_digits: 3 }), "3.667");
+  eq(mean(["1", "2", "8"], { ellipsis: true }), "3.666...");
+});
+
 test("is_infinity", ({ eq }) => {
   eq(is_infinity("-inf"), true);
   eq(is_infinity("inf"), true);