crisp is an interpreted functional programming language, inpsired by Lisp. It is implemented in C and currently in version alpha-1.0.0. Any contribution is welcome and appreciated. To understand the language you can check out programs directory where there are plenty of examples of how language works, how syntax and grammar is defined etc.

Before we start, you should know that you will be using parenthesis more than you have ever used. To display a Hello World message with Crisp, run the following code.

    (print "Hello world")

Even now with this code snippet, you probably understood that any function call or any builtin operation will be executed using this format: ([operation name] [..arguments]).

To sum, multiply, subtract or divide, we will again use parenthesis. In fact, there is no escape from parenthesis (I am so sorry).

     (+ 5 5)  //  10
     (- 5 5)  //  0
     (* 23 0) //  0
     (/ 0 0)  //  Divide by zero 0 exception will pop up. Learn your math!
     (+ (- 2 2) 5)  // 5
     (* 10 10 10)   // 1000

You can also use + operator on strings to concatenate them:

    (print (+ "Everbody " "loves" " crisp")) // prints a fact!

You can define variables two ways: using let or define. The difference between those two is that define allows you to define variables globally, whereas let expects you to give the scope of this variable as an expression.

(define x 10)

(print x)             // prints 10

(let x 5 (print x))   // prints 5

(print x)             // prints 10