Prototype programming in JavaScript
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The document contains a JavaScript code that defines various functions and classes related to data processing and manipulation. It includes logic for calculating proportions, rendering tables, and handling file operations. Additionally, it demonstrates the use of prototype-based programming with class definitions for geometric shapes such as squares and rectangles.
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
toString().padStart(width) : cell.padEnd(width); }).join(''))).join
}; const proportion = (max, val) => Math.round(val * 100 / max); co
calcProportion = table => { table.sort((row1, row2) => row2[DENSITY
row1[DENSITY_COL]); const maxDensity = table[0][DENSITY_COL]; table
forEach(row => { row.push(proportion(maxDensity, row[DENSITY_COL]))
return table; }; const getDataset = file => { const lines = fs.read
FileSync(file, 'utf8').toString().split('n'); lines.shift(); lines
return lines.map(line => line.split(',')); }; const main = compose
(getDataset, calcProportion, renderTable); const fs = require('fs'
compose = (...funcs) => x => funcs.reduce((x, fn) => fn(x), x); con
DENSITY_COL = 3; const renderTable = table => { const cellWidth = [
8, 8, 18, 6]; return table.map(row => (row.map((cell, i) => { const
= cellWidth[i]; return i ? cell.toString().padStart(width) : cell.p
(width); }).join(''))).join('n'); }; const proportion = (max, val)
Прототипное
программирование
Тимур Шемсединов
github.com/HowProgrammingWorks
Chief Software Architect at Metarhia
Lecturer at Kiev Polytechnic Institute
github.com/tshemsedinov](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-1-320.jpg)
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
1. point.__proto__ -> pointMethods
x: Number
y: Number
__proto__
point
move(x, y)
toString()
__proto__
pointMethods
point.__proto__
toString()
valueOf()
...
Object.prototype
pointMethods.__proto__
Object.prototype.__proto__
null](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-2-320.jpg)
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
2. function Point(x, y) { ... }
x: Number
y: Number
__proto__
point
move(x, y)
toString()
constructor
__proto__
Point.prototype
__proto__
toString()
valueOf()
...
Object.prototype
null
__proto__ __proto__
from(obj)
prototype
__proto__
Point
constructor
prototype
apply, bind, call,
constructor
...
Function.prototype
__proto__
__proto__](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-3-320.jpg)
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
3. class Point { ... }
x: Number
y: Number
__proto__
point
move(x, y)
toString()
constructor
__proto__
Point.prototype
__proto__
Object.prototype
null
__proto__ __proto__
from(obj)
prototype
__proto__
Point
constructor
prototype
Function.prototype
__proto__
__proto__
Object
Function](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-4-320.jpg)
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
4. (#1, #2) square -> Square -> Rect
x: Number
y: Number
width: Number
height: Number
__proto__
square
move(x, y)
constructor
__proto__
Square.prototype
__proto__
Objectnull
__proto__
prototype
__proto__
Square
constructor
prototype
toString()
constructor
__proto__
Rect.prototype
prototype
__proto__
Rect
constructor
prototype
__proto__
Square.prototype](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-5-320.jpg)
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
4. (#3, #4, #5) square -> Square -> Rect
x: Number
y: Number
width: Number
height: Number
__proto__
square
move(x, y)
constructor
__proto__
Square.prototype
__proto__
Objectnull
__proto__
prototype
__proto__
Square
constructor
prototype
toString()
constructor
__proto__
Rect.prototype
prototype
__proto__
Rect
constructor
prototype
__proto__](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-6-320.jpg)
![const fs = require('fs'); const compose = (...funcs) => x => funcs.
reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab
table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma
=> (row.map((cell, i) => { const width = cellWidth[i]; return i ? c
5. class Square extends Rect
x: Number
y: Number
width: Number
height: Number
__proto__
square
move(x, y)
constructor
__proto__
Square.prototype
__proto__
Object
__proto__
prototype
__proto__
class Square
constructor
prototype
toString()
constructor
__proto__
Rect.prototype
prototype
__proto__
class Rect
constructor
prototype
__proto__
__proto__
Function.prototype
__proto__](https://image.slidesharecdn.com/prototype-programming-javascript-191128095843/85/Prototype-programming-in-JavaScript-7-320.jpg)
Prototype programming in JavaScript
- 1. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c toString().padStart(width) : cell.padEnd(width); }).join(''))).join }; const proportion = (max, val) => Math.round(val * 100 / max); co calcProportion = table => { table.sort((row1, row2) => row2[DENSITY row1[DENSITY_COL]); const maxDensity = table[0][DENSITY_COL]; table forEach(row => { row.push(proportion(maxDensity, row[DENSITY_COL])) return table; }; const getDataset = file => { const lines = fs.read FileSync(file, 'utf8').toString().split('n'); lines.shift(); lines return lines.map(line => line.split(',')); }; const main = compose (getDataset, calcProportion, renderTable); const fs = require('fs' compose = (...funcs) => x => funcs.reduce((x, fn) => fn(x), x); con DENSITY_COL = 3; const renderTable = table => { const cellWidth = [ 8, 8, 18, 6]; return table.map(row => (row.map((cell, i) => { const = cellWidth[i]; return i ? cell.toString().padStart(width) : cell.p (width); }).join(''))).join('n'); }; const proportion = (max, val) Прототипное программирование Тимур Шемсединов github.com/HowProgrammingWorks Chief Software Architect at Metarhia Lecturer at Kiev Polytechnic Institute github.com/tshemsedinov
- 2. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c 1. point.__proto__ -> pointMethods x: Number y: Number __proto__ point move(x, y) toString() __proto__ pointMethods point.__proto__ toString() valueOf() ... Object.prototype pointMethods.__proto__ Object.prototype.__proto__ null
- 3. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c 2. function Point(x, y) { ... } x: Number y: Number __proto__ point move(x, y) toString() constructor __proto__ Point.prototype __proto__ toString() valueOf() ... Object.prototype null __proto__ __proto__ from(obj) prototype __proto__ Point constructor prototype apply, bind, call, constructor ... Function.prototype __proto__ __proto__
- 4. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c 3. class Point { ... } x: Number y: Number __proto__ point move(x, y) toString() constructor __proto__ Point.prototype __proto__ Object.prototype null __proto__ __proto__ from(obj) prototype __proto__ Point constructor prototype Function.prototype __proto__ __proto__ Object Function
- 5. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c 4. (#1, #2) square -> Square -> Rect x: Number y: Number width: Number height: Number __proto__ square move(x, y) constructor __proto__ Square.prototype __proto__ Objectnull __proto__ prototype __proto__ Square constructor prototype toString() constructor __proto__ Rect.prototype prototype __proto__ Rect constructor prototype __proto__ Square.prototype
- 6. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c 4. (#3, #4, #5) square -> Square -> Rect x: Number y: Number width: Number height: Number __proto__ square move(x, y) constructor __proto__ Square.prototype __proto__ Objectnull __proto__ prototype __proto__ Square constructor prototype toString() constructor __proto__ Rect.prototype prototype __proto__ Rect constructor prototype __proto__
- 7. const fs = require('fs'); const compose = (...funcs) => x => funcs. reduce((x, fn) => fn(x), x); const DENSITY_COL = 3; const renderTab table => { const cellWidth = [18, 10, 8, 8, 18, 6]; return table.ma => (row.map((cell, i) => { const width = cellWidth[i]; return i ? c 5. class Square extends Rect x: Number y: Number width: Number height: Number __proto__ square move(x, y) constructor __proto__ Square.prototype __proto__ Object __proto__ prototype __proto__ class Square constructor prototype toString() constructor __proto__ Rect.prototype prototype __proto__ class Rect constructor prototype __proto__ __proto__ Function.prototype __proto__