Victim

Victim is dynamically typed lexically scoped interpreted scripting language written in Haskell. The name is inspired by source code of malloc.

Installation

You need Glasgow Haskell Compiler and Cabal to install Victim interpreter on your computer. Installing GHCup on your computer will do these for you.

Before Installing GHCup

cd ~

Installing GHCup

curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh

Installing Victim

git clone https://github.com/Sekomer/Victim
cd Victim
cabal install -O2 --overwrite-policy=always 

creates Victim symlink to original binary.

or

just run setup.sh script (you have to press enter several times)

sh setup.sh

For those who want to try on docker image

Getting Dockerfile

wget https://raw.githubusercontent.com/Sekomer/Victim/main/dockerfile

Building Dockerfile

sudo docker build -t sekomer/victim .

Running Docker Image

sudo docker run -p 2222:22 --name victim --hostname victim -d sekomer/victim

Running SSH Server

ssh test@localhost -p 2222

On SSH Server, just run

$ sudo su
$ /root/.cabal/bin/Victim /root/Victim/examples/factorial.v

Usage

To run Victim interpreter.

Victim main.v

Data Types

name	description
Integer	Whole number
Double	Number with floating points
Bool	Truth values, internally Integer 0 and 1
String	Sequence of characters
Function	Subroutine
Null	Representation of uselessness, inspired by the legend

Examples

Examples are stored under example folder.

Language

Comments

-- this is a single line comment

{-
 this
 is
 a
 multi
 line
 comment
-}

Variable Decleration and Assignment

var keyword is used to declare a variable.

var num := null;    -- declare
num := 42           -- assign

Control Flow

-- single line conditional statements doesnt require braces
var cond := true;
if (cond) print( "yeey" );


-- multi line conditional statements require braces
var a  := 2;
var b  := 3;
var op := "add";

if ( op == "add" )
{
    var res := a + b;
    print(res);
}
else if ( op == "mul" )
{
    var res := a * b;
    print(res);
}
else    print( "unknown operation!" );

Case

case statements are clean alternatives of if-else statements. case keyword used to create a case statement, following expression is evaluated once and compared with the values of each when label. If none of them match, otherwise is executed.

var a  := 2;
var b  := 3;
var op := "mul";


case (op)
{
    when "add" =>
    {
        var f := anon x, y -> x + y;
        print( f(a, b) );
    }

    when "mul" =>
    {
        var f := anon x, y -> x * y;
        print( f(a, b) );
    }
    
    otherwise =>
        print("Unknown op!");
}

Loops

while and for keywords are used to create loop statements.

[*] while

while loops in the Victim language contain 2 sections; cond and body.

while cond expression is true, the body block is executed.

[ pseudo ]
while (cond) { statement(s); }

var condition := true;

while (condition)
{
    print( "YES!" );
}

[*] for

for loops in the Victim language contain 4 sections; init, cond, after and body.

init section is used for the decleration or assignment of variables.

cond section is evaluated before each execution the body. If it is left empty, it's considered as true like in the language of the gods.

after section is evaluated after each execution of the body. It can be empty.

body section contains what will be executed in the loop statement.

[ pseudo ]
for (init; cond; after) { statement(s); }

for (var i := 0; i < 42; i := i + 1)
{
    print( i );
}

following statements are also valid in Victim.

for (;;)
    print( "C is the best!" );

for (;; print("C is the best!"));

-- like the good old C

loops support both continue and break statements.

Functions

[*] Named Functions

Named functions can be created with fn keyword.

fn add(a, b)
{
    return a + b;
}

Functions are not required to have return statement. return statement without an expression and functions without return statements return null.

[*] Anonymous Functions

Anonymous functions can be created with the anon keyword. Anonymous functions are expressions, therefore, they need to be assigned to a variable or passed into the function as a parameter.

-- passed
fn apply (f, a, b)
{
    return f(a, b);
}

print( apply(anon x, y -> x**y, 5, 6) );

-- assigned
var f := anon x -> x**2;
print( f(5) );

Contributing

Please open an issue to discuss what you would like to change.

License

MIT