kcl → KCL

KCL Types

KCL defines the following types and keywords the language.

All these types can be nested in various forms where nesting applies. Like arrays can hold objects and vice versa.


true or false work when defining values.

Variable declaration

Variables are defined with the let keyword like so:

let myBool = false


An array is defined with [] braces. What is inside the brackets can be of any type. For example, the following is completely valid:

let myArray = ["thing", 2, false]

If you want to get a value from an array you can use the index like so: myArray[0].


An object is defined with {} braces. Here is an example object:

let myObj = {a: 0, b: "thing"}

We support two different ways of getting properties from objects, you can call myObj.a or myObj["a"] both work.


We also have support for defining your own functions. Functions can take in any type of argument. Below is an example of the syntax:

fn myFn = (x) => {
  return x

As you can see above myFn just returns whatever it is given.

Binary expressions

You can also do math! Let's show an example below:

let myMathExpression = 3 + 1 * 2 / 3 - 7

You can nest expressions in parenthesis as well:

let myMathExpression = 3 + (1 * 2 / (3 - 7))

Please if you find any issues using any of the above expressions or syntax please file an issue with the ast label on the modeling-app repo.