Flick Programming Language

A modern, expressive programming language with a focus on readability and developer experience. Flick features a unique syntax that eliminates parentheses for function calls, making code more natural to read.

Features

✨ Space-Separated Function Calls - No parentheses needed
🔌 Plugin System - Extensible with built-in plugins (web, files, time, random)
🌐 Web Server (Gazelle) - Built-in HTTP server with routing and nested modules
📦 JavaScript/TypeScript Imports - Use npm packages and Node.js modules seamlessly
🎯 Type Inference - Smart type handling with automatic conversions
🔄 Modern Control Flow - Intuitive syntax for loops and conditionals

Installation

npm install -g runflick

Usage

# Run a Flick file
flick run yourfile.fk

Syntax Examples

Variables

free name = "Alice"          # Mutable variable
lock maxUsers = 100          # Immutable constant
free count = num "42"        # Type conversion

Functions (Tasks)

task greet with literal(name) =>
    print "Hello, " and name
end

greet "World"  # No parentheses!

# Tasks can return values using 'give'
task double with num(x) =>
    give x * 2
end

free result = double 5
print result  # 10

# Tasks can be called without arguments
task sayHello =>
    print "Hello!"
end

sayHello  # Auto-calls even without ()

Ternary Expressions (Inline Assume)

# Inline conditional expressions
free age = 25
free status = assume age >= 18 => "Adult", otherwise => "Minor"
print status  # "Adult"

# Nested ternaries
free score = 85
free grade = assume score >= 90 => "A", otherwise => assume score >= 80 => "B", otherwise => "C"
print grade  # "B"

# Without otherwise (returns null if false)
free result = assume score > 100 => "Perfect"

Conditionals

assume age >= 18 =>
    print "Adult"
maybe age >= 13 =>
    print "Teenager"
otherwise =>
    print "Child"
end

Loops

# For-each loop
each item in items =>
    print item
end

# Range loop
march i from 1 to 10 =>
    print i
end

Groups (Classes)

group Player {
    free num health = 100
    free literal name
    
    task takeDamage with num(amount) =>
        health := health - amount
        print name and " took damage!"
    end
    
    task getHealth =>
        give health  # Return current health
    end
}

free player = Player "Alice"
player/takeDamage 15  # You can also use dot notation! <player.takeDamage 15>

free currentHealth = player/getHealth
print currentHealth  # 85

# Groups without required fields can be instantiated without arguments
group Counter {
    free num count = 0
    
    task increment =>
        count := count + 1
        give count
    end
}

free Counter counter = Counter  # Auto-instantiates
free value = counter/increment
print value  # 1

Blueprints (Interfaces)

blueprint Drawable {
    task draw
}

do Drawable for Player =>
    task draw =>
        print "Drawing player: " and name
    end
end

JavaScript/TypeScript Imports

import {readFileSync, writeFileSync} from "node:fs"
import {resolve} from "node:path"

free content = readFileSync "package.json", "utf-8"
free data = JSON/parse content
print data/name

writeFileSync "output.txt", "Hello from Flick!"

Web Server (Gazelle Plugin)

declare web@3000

route GET "/" =>
    respond "Welcome to Flick!"
end

route POST "/api/users" =>
    free user = body
    respond json={"id": 1, "name": user.name}, status=201
end

# Access request data
route GET "/search" =>
    print query/term
    print headers["user-agent"]
    respond json=query
end

Nested Routing

# main.fk
declare web@8080
use AuthRoutes

route "/" =>
    respond "Home"
end

route "/auth" -> AuthRoutes

# AuthRoutes.fk
declare web@module

route "/login" =>
    respond json={"token": "abc123"}
end

route POST "/logout" =>
    respond json={"success": yes}
end

Built-in Plugins

Files Plugin

declare files

free content = read "file.txt"
write "output.txt", "Hello"
assume exists "config.json" =>
    print "Config found!"
end

Time Plugin

declare time

free timestamp = now
print timestamp

sleep 1000  # Wait 1 second
print "Done waiting"

Random Plugin

declare random

free randNum = random
free dice = randint 1, 6
free shuffled = shuffle myArray
free pick = choice myArray

File Extension

Flick files use the .fk extension.

Keywords

Control Flow: assume, maybe, otherwise, each, march, select, when
Declarations: group, blueprint, task, free, lock, declare, use, import
Statements: print, respond, route, do, for, with, in, from, to, give
Booleans: yes, no
Types: num, literal
Operators: := (assignment), = (assignment/equality), and (concatenation in print), / or . (member access)

Special Features

Return Values

Use give to return values from tasks:

task findFirst with num(threshold) =>
    march i from 1 to 10 =>
        assume i > threshold =>
            give i  # Early return
        end
    end
    give -1  # Not found
end

free result = findFirst 6
print result  # 7

Auto-calling Functions

task greet =>
    print "Hello!"
end

greet  # Auto-calls

# Groups auto-instantiate when assigned with type annotation
group Counter {
    free num count = 0
}

free Counter c = Counter  # Auto-instantiates

Empty Checks

Empty strings, empty arrays, and empty objects are falsy:

assume body =>  # True if body is not empty
    print "Has data"
end

Input Function

The ask function prompts for user input and automatically uses an empty prompt if none is provided:

lock input = ask "Enter your name: "
print "Hello, " and input

# Can be used without prompt
lock value = ask
free result = ask + 1  # Asks with empty prompt, then adds 1

Request Handling (Web Plugin)

Available in route handlers:

• req - Full request object
• body - Parsed request body (JSON auto-parsed)
• query - Query parameters object
• headers - Request headers object

Example: Complete Web API

declare web@3000
declare files

free database = JSON/parse (read "<path_from_workdir>/db.json")

route GET "/api/users" =>
    respond json=database.users
end

route POST "/api/users" =>
    free user = body
    free userId = database/users/length + 1
    # Add user to database...
    respond json={"id": userId, "name": user.name}, status=201
end

route GET "/api/users/:id" =>
    free userId = query/id
    respond json={"message": "User " + userId}
end

License

ISC