FUNX

Joaquim Torra Garcia

FIB LP 2022-2023

https://github.com/gebakx/lp-funcions

Funx is an interpreted functional programming language written in ANTRL4 and Python.

Build

Clone this repository to your local machine and use the following command to generate the Lexer and Parser.

antlr4 -Dlanguage=Python3 -no-listener -visitor Funx.g4

Usage

Currently there's 2 options to use Funx in your machine:

Web Page

Run flask --app funx.py run to start the server. Using your favorite browser, go to 127.0.0.1:5000 and start using Funx.
CLI Interpreter

Run python funx_cli.py to start the Funx interpreter on your machine.

Funx is designed to work always in the same way:

Declarations
Solve a single statement

This is how a Funx example would look like:

# Declare the function
Fibo n
{
    if n < 2 { n }
    (Fibo n-1) + (Fibo n-2)
}

# Run the function
Fibo 5

Syntax

Expressions

You can run any simple expression with numbers:

# addition
1 + 1
> 2

# multiplication
5 * 10
> 50

You can also perform some of these operations with Lists

1 + [2, 3, 4]
> [1, 2, 3, 4]

[1, 2, 3] + 4
> [1, 2, 3, 4]

[1] + [2]
> [1, 2]

Additionally, you can work with booleans

True and False
> False

True and True
> True

False or False
> False

not False
> True

Here's the list of available operations:

binary ops: +, -, *, /, %, ^

locig ops: =, !=, >, <, >=, <=, and, or, xor, not

Lists

# Initialize a simple list and save it on a variable a
a <- [1, 2, 3, 4]

# Get a single value from the list
a[0]
> 1

# Get a sublist
a[1:3]
> [2, 3]

# Initialize a ranged list
a <- [1..10]
a
> [1, 2, 3, 4, 5, 6, 7, 8, 9]

Variables

In Funx, variables always are named starting with a lowercase letter.

A variable is defined at the moment of it's assignment.

To assign a value to a variable we use <-:

a <- 3

b <- a + 4

Conditionals

If-Then-Else functions don't need parenthesys

if expression
{

}
else
{

}

Loops

Both loops, while and for, are available:

# While loop
a <- 3
while a > 0 {
    a <- a-1
}

# For loop
l <- [1, 2, 3, 4]
s <- 0
for x in l {
    s <- s + x
}

Functions

Functions, in the other hand, are named starting with a capital letter.

This is an example of a function declaration:

# The function Suma receives 2 arguments
# x and y and adds them together
Suma x y {
    x + y
}

Input/Output

We have some i/o ops that are rarely used.

print x will print the variable x on screen without returning the value

input x will wait for user input and assign it's value to the variable x

QuimTorra/Funx