Module

mod keyword defines a new module.

mod bar where
    # contents #

Modules can be defined in three ways:

Where

mod <name> where
    # contents #

Defines an new module with given items.

File

mod <name> file <file_name>

Defines a module in another file.

Example

File main.rim

mod bar file bar

File main/bar.rim:

val foo = 1 + 2

Alias

mod <name> = <path>

Example

mod alias = path.to.another.module

Comment

Comments are written between # symbols

# This is a comment! #

Multi-line comments

#
    This is a
    multi-line
    comment!
#

Identifier

Identifiers are in camelCase style, no matter whether it's a module name or a value name.

Unlike most of other programming languages, identifiers here can start on a digit, or even be a number.

Allowed characters

English alphabet letters from a to z, uppercase or lowercase.
Digits from 0 to 9.

An identifier can also be the same as any of language special keywords, such as mod or let.

Examples

val thisIsValueName = 100

If an identifier is a special keyword or starts with a digit, its usage must contain . at the beginning (in most of the places, but not everywhere).

let
    val val = 5
in
    val hello = .val + 5 # 10 #

# a module called `mod` (special keyword) #
let mod mod where
    # module contents #
in
    # no need to put a period here #
    mod alias = mod

let val 3d = 1 + 1
in val bar = .3d * 10 # 20 #

Do not put a period . if an identifier is not at the beginning of a path:

let bar = this.is.path.3d
# NOT: this.is.path..3d #

Path

A path consists of identifiers (module names), separated by ..

let
    mod this where
        mod is where
            mod a where
                mod path where
                    let value = 5
in
    mod alias = this.is.a.path

A path can also have a period (.) before it:

mod alias = .this.is.a.path

This is useful when dealing with some types of identifiers:

let
    val 10StartsWithDigit = 100
in
    val used = .10StartsWithDigit + 1 # 101 #