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Master Clojure.

Clojure

Clojure mastery exercises. Become your team's resident Clojure expert.

196 exercises

Clojure

Clojure Challenges

Put your Clojure skills to the test. Practice by building popular open-source tools from scratch.

Build your own Interpreter

Build your own Interpreter

This challenge follows the book Crafting Interpreters by Robert Nystrom.

In this challenge you'll build an interpreter for Lox, a simple scripting language. Along the way, you'll learn about tokenization, ASTs, tree-walk interpreters and more.

Before starting this challenge, make sure you've read the "Welcome" part of the book that contains these chapters:

Introduction (chapter 1)
A Map of the Territory (chapter 2)
The Lox Language (chapter 3)

These chapters don't involve writing code, so they won't be covered in this challenge. This challenge will start from chapter 4, Scanning.

Scanning: Empty file

Scanning: Parentheses

Scanning: Braces

Scanning: Other single-character tokens

Scanning: Lexical errors

Scanning: Assignment & equality Operators

Scanning: Negation & inequality operators

Scanning: Relational operators

Scanning: Division operator & comments

Scanning: Whitespace

Scanning: Multi-line errors

Scanning: String literals

Scanning: Number literals

Scanning: Identifiers

Scanning: Reserved words

Parsing Expressions

Number literals

String literals

Unary Operators

Arithmetic operators (1/2)

Arithmetic operators (2/2)

Comparison operators

Equality operators

Syntactic errors

Evaluating Expressions

Literals: Booleans & Nil

Literals: Strings & Numbers

Unary Operators: Negation & Not

Arithmetic Operators (1/2)

Arithmetic Operators (2/2)

String Concatenation

Relational Operators

Equality Operators

Runtime Errors: Unary Operators

Runtime Errors: Binary Operators (1/2)

Runtime Errors: Binary Operators (2/2)

Runtime Errors: Relational Operators

Statements & State

Print: Generate output

Print: Multiple statements

Expression statements

Variables: Declare variables

Variables: Runtime Errors

Variables: Initialize variables

Variables: Redeclare variables

Assignment operation

Control Flow

Else statements

Else-if statements

Nested if statements

Logical OR operator

Logical AND operator

While statements

Syntactic errors

Functions

Native functions

Functions without arguments

Functions with arguments

Return statements

Higher order functions

Resolving & Binding

Identifier Resolution

Self Initialization

Variable Redeclaration

Classes

Class Declarations

Class Instances

Getters & Setters

Instance Methods

The 'this' keyword

Invalid usages of 'this'

Constructor calls

Return within constructors

Inheritance

Class Hierarchy

Inheriting Methods

Overriding Methods

Inheritance errrors

The super keyword

Invalid Usages of the super Keyword

Build your own Redis

FREE THIS MONTH

Build your own Redis

Discover concurrent programming in Clojure while also learning about TCP servers, network programming, and the Redis Protocol.

Respond to PING

Respond to multiple PINGs

Handle concurrent clients

Implement the ECHO command

Implement the SET & GET commands

Lists

Append an element

Append multiple elements

List elements (positive indexes)

List elements (negative indexes)

Prepend elements

Query list length

Remove an element

Remove multiple elements

Blocking retrieval

Blocking retrieval with timeout

Streams

The TYPE command

Create a stream

Validating entry IDs

Partially auto-generated IDs

Fully auto-generated IDs

Query entries from stream

Query single stream using XREAD

Query multiple streams using XREAD

Blocking reads without timeout

Blocking reads using $

Transactions

The INCR command (1/3)

The INCR command (2/3)

The INCR command (3/3)

The MULTI command

The EXEC command

Empty transaction

Queueing commands

Executing a transaction

The DISCARD command

Failures within transactions

Multiple transactions

Replication

Configure listening port

The INFO command

The INFO command on a replica

Initial replication ID and offset

Send handshake (1/3)

Send handshake (2/3)

Send handshake (3/3)

Receive handshake (1/2)

Receive handshake (2/2)

Empty RDB transfer

Single-replica propagation

Multi-replica propagation

Command processing

ACKs with no commands

ACKs with commands

WAIT with no replicas

WAIT with no commands

WAIT with multiple commands

RDB Persistence

RDB file config

Read a string value

Read multiple keys

Read multiple string values

Read value with expiry

Pub/Sub

Subscribe to a channel

Subscribe to multiple channels

Enter subscribed mode

PING in subscribed mode

Publish a message

Deliver messages

Sorted Sets

Create a sorted set

Retrieve member rank

List sorted set members

ZRANGE with negative indexes

Count sorted set members

Retrieve member score

Remove a member

Geospatial Commands

Respond to GEOADD

Validate coordinates

Store a location

Calculate location score

Respond to GEOPOS

Decode coordinates

Calculate distance

Search within radius

Build your own SQLite

Build your own SQLite

Learn about B-Trees, the foundation of every relational database. Explore Clojure's API for reading/writing files, and handling custom file formats.

Print page size

Print number of tables

Print table names

Count rows in a table

Read data from a single column

Read data from multiple columns

Filter data with a WHERE clause

Retrieve data using a full-table scan

Retrieve data using an index

Build your own HTTP server

Build your own HTTP server

HTTP is the protocol that powers the web. In this challenge, you'll build a HTTP server from scratch using TCP primitives. Your server will be capable of handling simple GET/POST requests, serving files and handling multiple concurrent connections.

Along the way, we'll learn about TCP connections, HTTP headers, HTTP verbs, handling multiple connections and more.

Respond with 200

Extract URL path

Respond with body

Concurrent connections

Read request body

HTTP Compression

Compression headers

Multiple compression schemes

Gzip compression

Persistent Connections

Persistent connections

Concurrent persistent connections

Connection closure

Many more to come...

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