The ECMA-262 ECMAScript® Language Specification.

The Revised 7 Report on the Algorithmic Language Scheme.

At most, we can say it is written in English, or more precisely, in a specific jargon of English, a semi-format subset of English extended with logic notation.ĭifferent specifications are written in different styles, here is an example of some specifications: It isn't 'written in' anything (in the sense that e.g. a Compiler or Interpreter) like PyPy or Clang.Ī Programming Language is a set of semantic and syntactic rules and restrictions. You seem to be confusing a Programming Language like Python or C with a Programming Language Implementation (e.g. Machine code came first, and the first assemblers were themselves very very simple (early assembly languages were very easy to parse and generate machine code for), they were written in machine code, until bootstrapped and self-hosted.

So what came first, and what was that coded in?

This akin to the bootstrapping exercise (limited to a new feature rather than the whole language).īut to be clear, there is the potential (and often realized) for the programming language to be written in the latest version of its input language. When the Roselyn compiler adds a new language feature, they won't use it in the source code for the compiler until it is debugged and working (e.g. For example, C compilers are written in C or C++ and C#'s Roselyn compiler is written in C#. Once bootstrapped, programming languages can self-host, so they are often written in the same language they compile. Some of the runtime code will drop into assembly to access certain hardware instructions or code sequences not easily obtained through the compiler.

Programming language compilers and runtimes are written in programming languages - not necessarily languages that are older or are different than the one they take as input. What are programming languages written in?

Write programming language