• From: "Costello, Roger L." <costello@m...>
• To: "xml-dev@l..." <xml-dev@l...>
• Date: Mon, 12 Jan 2015 16:30:53 +0000

Here's another example of a language that is defined using the language itself:

This document defines the Augmented BNF (ABNF) using ABNF:

https://tools.ietf.org/html/rfc5234#section-4

That is the ABNF-for-ABNFs!

Neat!

/Roger

-----Original Message-----
From: Costello, Roger L. 
Sent: Saturday, January 10, 2015 3:43 PM
To: xml-dev@l...
Subject: Defining a language using itself

Hi Folks,

I think it is mind-blowing when a language is defined using the language itself.

This document defines the XML Schema language using XML Schema:

http://www.w3.org/TR/xmlschema11-1/#normative-schemaSchema

That is the XML schema-for-schemas!

This document defines the JSON Schema language using JSON Schema:

http://json-schema.org/draft-04/schema# 

That is the JSON schema-for-schemas!

These two documents define the ANTLR grammar language using the ANTLR grammar:

https://github.com/antlr/grammars-v4/blob/master/antlr4/ANTLRv4Parser.g4
https://github.com/antlr/grammars-v4/blob/master/antlr4/ANTLRv4Lexer.g4

That is the ANTLR grammar-for-grammars!

Neat!

Do you know of other languages that are defined using the language itself?

/Roger

• Follow-Ups:
  • Re: RE: Defining a language using itself
    • From: Thomas Passin <list1@t...>
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• References:
  • Defining a language using itself
    • From: "Costello, Roger L." <costello@m...>