Prolang

A Simple human readable functional programming language

Goals

1. Simple
2. Readable
3. Ease of learning

Solution

(basic) python clone with brackets

variable declaration

name = "peter parker"
age = 21

---

Immutability

variables are immutable by default for mutable variables, use the let keyword

let is_gwen_alive = true

---

conditional statements

a = number(input(""))

if a % 5 is 0 and a % 7 is 0 {
    print("FizzBuzz")
} else if a % 5 is 0 {
    print("Fizz")
} else if a % 7 is 0 {
    print("Buzz")
} else {
    print(a)
}

input(args...) write the args in the console and read an input from it

number(arg) convert the string to number if possible

note: is and is not are identity operators similar to == and != respectively

note: curly brackets are optional for a block if it contains only single statement

---

unconditional loop

loop {
    print("got stuck in an infinite loop")
}

---

conditional loop

while loop

exits when the condition gets false

let a = 10

loop while a > 0 {
    print(a)
    a -= 1
}

while loop

exits when the condition gets true

let a = 10

loop until a is 0 {
    print(a)
    a -= 1
}

note: loops are just single statement you can substitute loop block with any other regular blocks

if a is 0 loop {
    print("a is zero, is zero a number?")
}

using loop with conditional statements together

if a < 0 loop while a is 0 {
    print($"a is negative and it is {a}")
    a += 1
}
else if a is 0 loop while a < 10 {
    print($"a is single digit and it is {a}")
    a += 1
}
else loop while a < 100 {
    print($"a is double digit and it is {a}")
    a += 1
}

note: you can use $ to interpolate variables in strings

function declaration

add = (a, b) => a + b

connectToDB = (url) => {
    if url is "" {
        return false
    }
    # connect to the database
    connection
}

note: by default functions return the last expression

global functions

• print (takes any number of arguments and prints them to stdout)
• input (takes optional string as argument and prints it to stdout and returns the input from stdin)
• number (converts string to number)
• yet to add more