From a3bacd66a903ba10407a2bf910fd181c3bb62f0b Mon Sep 17 00:00:00 2001
From: "Grevcev.AS" <grevcev.as@dns-shop.ru>
Date: Fri, 29 Oct 2021 07:46:24 +1000
Subject: [PATCH] lab partialApplication

---
 Exercises/1-power.js    | 12 +++---------
 Exercises/2-closure.js  |  6 +++---
 Exercises/3-lambda.js   |  7 ++++++-
 Exercises/4-bind.js     |  4 ++--
 Exercises/5-curry.js    |  8 +++++++-
 Exercises/6-chaining.js | 13 ++++++++++++-
 6 files changed, 33 insertions(+), 17 deletions(-)

diff --git a/Exercises/1-power.js b/Exercises/1-power.js
index 9a99509..8b096af 100644
--- a/Exercises/1-power.js
+++ b/Exercises/1-power.js
@@ -1,15 +1,9 @@
 'use strict';
 
-// Define function power(exp, n), the same as Math.pow(n, exp)
-// but with reverse order of argumants.
-const power = null;
+const power = (exp, n) => Math.pow.bind(null, n, exp)();
 
-// Implement function `square(n)`, which returns square of its argument.
-// The function may or may not reuse function `power`.
-const square = null;
+const square = (n) => power(2, n);
 
-// Implement function `cube(n)` using partial application
-// The function should return cube of argumant (to the power of three).
-const cube = null;
+const cube = (n) => Math.pow.bind(null, n, 3)();
 
 module.exports = { power, square, cube };
diff --git a/Exercises/2-closure.js b/Exercises/2-closure.js
index d6f2435..a419f96 100644
--- a/Exercises/2-closure.js
+++ b/Exercises/2-closure.js
@@ -3,13 +3,13 @@
 const coffee = (volume, strength) =>
   `Coffee volume: ${volume}ml, strength: ${strength}`;
 
-const defineCoffeeType = volume => strength => coffee(volume, strength);
+const defineCoffeeType = (volume) => (strength) => coffee(volume, strength);
 
 // Use function defineCoffeeType to define new coffee types.
 // Define coffee type espresso which volume should equal 50ml.
 // Define coffee type americano which volume should equal 150ml.
 
-const espresso = null;
-const americano = null;
+const espresso = defineCoffeeType(50);
+const americano = defineCoffeeType(150);
 
 module.exports = { espresso, americano };
diff --git a/Exercises/3-lambda.js b/Exercises/3-lambda.js
index 994caa8..c2e510d 100644
--- a/Exercises/3-lambda.js
+++ b/Exercises/3-lambda.js
@@ -6,6 +6,11 @@ const tagged = (pref, str) => `[${pref}] ${str}`;
 // E.g. tagDate('My String') === '[2019-11-14] My String'
 // Use function tagged to implement tagDate.
 
-const tagDate = null;
+const tagDate = (string) => {
+  const todayDate = new Date();
+  const formatedDate = todayDate.toISOString().substring(0, 10);
+
+  return tagged(formatedDate, string);
+};
 
 module.exports = { tagDate };
diff --git a/Exercises/4-bind.js b/Exercises/4-bind.js
index 1d1849a..15b04fc 100644
--- a/Exercises/4-bind.js
+++ b/Exercises/4-bind.js
@@ -19,7 +19,7 @@ const H = (exp, ...args) => {
 // Create function `average` that returns arithmetic mean (H₁) of the arguments.
 // Create function `rootMeanSquare` that returns quadratic mean (H₂).
 
-const average = null;
-const rootMeanSquare = null;
+const average = (...args) => H.bind(null, 1, ...args)();
+const rootMeanSquare = (...args) => H.bind(null, 2, ...args)();
 
 module.exports = { average, rootMeanSquare };
diff --git a/Exercises/5-curry.js b/Exercises/5-curry.js
index e175699..3da9cdc 100644
--- a/Exercises/5-curry.js
+++ b/Exercises/5-curry.js
@@ -7,7 +7,13 @@ const checkPin = (...code) => code.join('') === EXPECTED_PIN;
 // Define function curry that accepts the length of the function
 // (amount of function arguments) and the function.
 
-const curry = (length, fn) => (...args) => null;
+const curry = (length, fn) => (...args) => {
+  if (length !== 1) {
+    const f = fn.bind(null, ...args);
+    return curry(length - 1, f);
+  }
+  return fn(...args);
+};
 
 // Allows to enter pin code by one character,
 // Usage: press('3')('4')('5')('6')
diff --git a/Exercises/6-chaining.js b/Exercises/6-chaining.js
index b0b2d26..337c7e9 100644
--- a/Exercises/6-chaining.js
+++ b/Exercises/6-chaining.js
@@ -10,6 +10,17 @@ const checkPin = (...code) => code.join('') === EXPECTED_PIN;
 //
 // For hint use https://github.com/HowProgrammingWorks/Cheatsheet
 
-const press = null;
+const press = (code) => {
+  let pin = code;
+  return {
+    press(i) {
+      pin += i;
+      if (4 === pin.length) {
+        return checkPin(pin);
+      }
+      return this;
+    }
+  };
+};
 
 module.exports = { press };