JurjenLang

An untyped interpreted functional programming language

Getting started

Follow these three steps on your computer to get started

1. git clone https://github.com/JVerbruggen/JurjenLang.git
2. py -m pip install antlr4-python3-runtime
3. start input.bat or py project.py .\input.jur

The repository includes a java folder, which is exclusively used for the antlr4 testrig. I wont be implementing any logic there.

Making changes

If you made changes to the language or anything else, and the python files (and java classes for testrig) have to be regenerated, use the following steps:

1. Make sure you are in the root folder of the repository
2. Install ANTLR4 on windows
3. start .\generate_python.bat should renew all files

Testrig

To use the antlr4 testrig (which generates a parse tree), use the following tutorial:

1. Renew java files start .\generate_java.bat
2. Navigate to the java/ file cd java
3. start .\testrig.bat should open a command window and eventually open up the testrig

Language Specifications

Declare a variable

somevariable = 3
another = .2f
thirdvar = "some random text"
fourthboolean = true

Currently, only four types are allowed; integer, float, string and boolean. Why would you ever want more? ...Right?

Define a function

func myfunction a b{
  return a + b
}

result = myfunction(1,2)    # will be 3

In JurjenLang, variables have no type definition or hinting. This can either make your life easy or difficult, depending on who you ask. Either way, I don't really care.

Pass function as a parameter

func printstringone {
    print "one"
}

func printstringtwo {
    print "two"
}

func printspec printfunction {
    printfunction()
}

printspec(printstringone)     # prints 'one'
printspec(printstringtwo)     # prints 'one'

In JurjenLang, you can pass a reference to a function as a parameter. This reference can then be executed as if it is a function itself.

Expressions

a = 2
b = 3

thisbooleanwillbefalse = a == b
thisbooleanwillbetrue = a != b
thisonewillalsobetrue = a < b

JurjenLang supports a couple of expression operators; <, <=, >, >=, ==, !=

Boolean expressions

thiswillbetrue = true and true
thiswillbetrue = true or false
thiswillbefalse = not true

JurjenLang supports three boolean expressions; and, or, not

Numerical operators

a = 3 * 4     # multiplication
b = 12 / 3    # division
c = 5!        # factorial
d = 5 + 4 - 1 # addition and subtraction
e = 2^6       # pow

JurjenLang supports the numerical operators that can be seen above.

Output

print "i like to print stuff"
print 3*2

In JurjenLang you can print all variables.

Dangerous feature that I won't remove because its kind of useful but also the reason why this language should never be used in production

printscope

In JurjenLang you can print all variables on the scope with the printscope keyword

String multiplication (useless but fun feature)

mystring = "wohoo"*2
reversed = mystring*-2

print mystring          # Will be "wohoowohoo"
print reversed          # Will be "oohowoohowoohowoohow"

In JurjenLang you can multiply strings by an integer, both positive and negative.