Bru Lang

Bru is a simple markup language with JSON-like semantics.

It's currently used in Bruno to save details of an api request in a file.

Here is a sample .bru file:

http: {
  method: 'GET'
  url: 'https://www.usebruno.com/hello'
  headers: {
    Content-Type: 'application/json'
  }
  body: {
    type: 'xml'
    data: (
      <xml>
        <name>Bru</name>
      </xml>
    )
  }
}

Design Goals

Human readable
Easy to represent multi line strings
Support duplicate keys in dictionary - Multimap
Indentation based syntax
Annotations for providing additional information

The top level of a .bru file is an implicit Multimap. It does not require or support braces.

Except where noted, blank lines and whitespace are ignored.

Data Types

Primitive Types

There are 4 primitive types in Bru.

String
Number
Boolean
Null

The string type slightly differs from JSON in that a Bru string is a single-quoted and is always UTF-8. It may contain any printable UTF-8 character except ' or \n. Whitespace is considered significant inside of the quoted string.

Composite Types

There are 3 composite types in Bru.

Multimap

Multimap is a dictionary (key-value pair) with duplicate keys, enclosed in curly braces ({}). Keys and Values are separated by a colon : and key-value pairs are separated by a newline (\n).

All keys are unquoted strings and must not contain spaces. Values may be primitive or composite types. Some contexts may offer further restrictions not required by the Bru language.

{
  name: 'Bru'
  social: {
    github: 'https://github.com/usebruno/bru-lang'
    twitter: 'https://twitter.com/use_bruno'
  }
}

Array

Array is a list of values separated by a newline (\n), enclosed in square brackets ([]).

tags: [
  'markup langauge'
  'dsl'
]

Multiline String

Multiline string is a string that spans multiple lines, enclosed in parentheses (()). The content must begin on the line after the opening parenthesis (() and the closing parenthesis ()) must be on the line after the end of the multiline string. Multiline strings are indented at least two spaces more than the key which contains them. This indentation is removed on parsing.

article: {
  title: 'Bru Lang'
  content: (
    Bru is a simple markup language with json like semantics.
    It's currently used in Bruno to save details of an api request in a file.
  )
}

In the above example, the content will be:

Bru is a simple markup language with json like semantics.
It's currently used in Bruno to save details of an api request in a file.

Annotations

Annotations are used to provide additional information about a key-value pair. An annotation starts with (@) and ends with a newline (\n). Arguments may be passed to an annotation in parentheses (()) and separated by commas. Argument values may only be primitive types.

http: {
  method: 'GET'
  url: 'https://www.usebruno.com/hello'
  headers: {
    Content-Type: 'application/json'

    @disabled
    @description('This is a sample request')
    Authorization: 'Bearer{{token}}'
  }
  param: {
    query: {
      @description('The status of the user')
      @enum('active', 'inactive')
      status: 'active'
    }
  }
}

Comments

Comments start with # and end with a newline \n.

# This is a comment

http: {
  # This is a comment, too
}

halostatue/bru-lang