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Fika is a modern programming language for the web. It is statically typed, functional and runs on the BEAM (Erlang VM).

Project status: Actively developed. Not ready for production use or HackerNews.

If you'd like to keep tabs on our progress, please subscribe to our updates here.

Syntax

Here's a quick walkthrough of Fika's syntax.

Functions

A function in Fika looks like this:

# example.fi
fn sum(a: Int, b: Int) : Int do
  a + b
end

This is a function named sum which takes two integers and returns another integer. Identifiers in Fika are written in snake_case (similar to Ruby, Elixir or Python). Types are written in CamelCase.

Fika has a type checker which makes sure your functions actually return what they say they do. For example, the type checker will report an error for the following code:

fn sum(a: Int, b: Int) : Float do
  a + b
end

# Error: "Expected type: Float, got: Int"

All functions in Fika are nested inside modules. Module names in Fika are inferred from their file paths, so a Fika file named example.fi will become a module named example. All functions inside this file will belong to this module.

The sum function can be called like so:

# Calling locally within the module
sum(40, 2)

# Calling remotely outside the module
example.sum(40, 2)

If-Else expressions

An if-else expression in Fika looks like this:

if true do
  a = "we have if-else now!"
  200
else
  404
end

Basic types and operators

Fika is currently a proof of concept so its data types and operators are quite limited.

Data types - atoms, integers, strings, booleans, lists and records. Operators - assignment(=), logical(&, |) and arithmetic(+, -, *, /).

# This is a comment

# Type: Int
a = 40
b = 2
c = a + b

# Type: String
str = "Hello world"

# Type: Bool
x = true

# Type: List(Int)
list_of_ints = [1, 2, 3]

# Type: {String,Bool}
tuple = {"tuple", true}

# Type: {foo: Int}
record = {foo: 123}

example.fi has working examples that demonstrate the syntax.

Running Fika programs

Fika is written in Elixir, so make sure you have that installed. Follow these instructions to install Elixir. Next, clone this repo, cd into the directory and then follow the below instructions.

Using Elixir shell

# Install dependencies and run the Elixir shell
mix deps.get
iex -S mix

# In the Elixir shell, compile and load a Fika file using the following:
> Fika.Code.load_file("example.fi")

# Now you can run functions from the module like this:
> :example.sum(40, 2)
> 42

Using fika executable

# Create the executable
mix escript.build

# Call the function example.sum(1, 2) from the file example.fi
./fika exec --function="sum(1, 2)" example.fi

Your first HTTP server

Fika comes with a webserver which allows you to quickly create HTTP request handlers. By default, Fika looks for routes in a function called router.routes(), so you need to define that first:

Note: This webserver is a prototype for now and only responds with strings and a 200 status code.

# Inside router.fi
fn routes : List({method: String, path: String, handler: Fn(->String)}) do
  [
    {method: "GET", path: "/", handler: &greet}
  ]
end

fn greet : String do
  "Hello world"
end

Now start the webserver in one of two ways:

Using Elixir shell

# router.fi is in the `examples` folder
> Fika.start("examples")

# Reload routes after changing routes.fi
> Fika.RouteStore.reload_routes()

Using fika executable

# Create the executable
mix escript.build

# router.fi is in the `examples` folder
./fika start examples

# Re-run the command after making changes to routes.fi

Now open http://localhost:6060 in the browser to see "Hello world" served by Fika.

Fika together!

If you'd like to be part of the Fika community, you can find us here:

This is the best place to chat with Fika developers, ask questions or get guidance on contributing to Fika. We also livestream some talks and pair programming sessions here. Here's the link to join.

This is an email digest where we send out the latest updates about Fika and our ecosystem. Here's the link to subscribe.

If you'd like to contact the creator of Fika, you can find Emil Soman on twitter or drop a mail to [email protected].

Thanks

Fika's development is supported by its many contributors and the grant from FOSSUnited. Thank you!