Types

behave has multiple inbuilt types, and also lets you define your own, custom types.

Strings

Strings are denoted by the type str.

You can create string literals by surrounding your text with double quotes ("). For example, "Hello, World!" creates a string that contains the text Hello, World!.

Numbers

Numbers are denoted by the type num.

They can hold any number that can be an integer or floating-point number.

Booleans

Booleans are denoted by the type bool.

They can hold a value that is either true or false.

Arrays

Arrays can hold a list of one specific type: this can be a composite type like a map, another array, a sum type, or even user-defined types like structs and enums.

They are denoted by the type [<type>], where <type> is any type.

You can create array literals:

[<expr>, <expr>, ...]
/// Which would be something like:
["Hello" + "World", "Hi"]

expr: Is an expression that results in the type of the array. All of the types must be exactly the same.

Maps

Maps can hold a set of key-value pairs, each of which can be any type.

They are denoted by the type [<type> : <type>].

You can create map literals:

[<expr> : <expr>, <expr> : <expr>, ...]
/// Which would be something like:
["From string" : 1 + 2.0]

Sum types

You can create sum types (which are essentially types that can be either one type or another).

Sum types are denoted by <type> | <type> | <type>.

They can be instantiated with any of the allowed types.

Functions

behave has first-class functions (I don't know why).

They are denoted by fn(<type>, <type>) -> <type>, where the return type and arguments are optional.

You can create functions:

fn (<ident>: <type>, ...) -> <type> {
    <code>
}
/// Which would be something like:
fn (cool_number: num) -> num {
    cool_number * 2
}

Structs

You can create your own structs in secondary files.

They are defined:

struct <ident> {
    <ident>: <type>,
    <ident>: <type> = <expr>,
    ...
}
/// Which would be something like:
struct MyStruct {
    a_number: num,
    a_string: str,
    a_default: str = "Hello"
}

You can instantiate them:

<path> {
    <ident>: <expr>,
    ...
}
/// Which would be something like:
MyStruct {
    a_number: 69,
    a_string: "This is a struct"
}

Enums

You can create custom enumerations to signify that a value can only be one out of a certain set. They are also defined in secondary files.

They are defined:

enum <ident> {
    <ident>,
    <ident> = <number>,
    ...
}
/// Which would be something like:
enum MyEnum {
    This,
    That = 2,
    There = 5
}

They can be instantiated:

<path>.<ident>
/// Which would be something like:
MyEnum.There