The PyCon UK 2017 CFP is here: http://2017.pyconuk.org/cfp/

Now that I've logged into HQ, I can see that the proposal is required to have:

• title, 60 characters;
• Subtitle, 120 characters;
• co-presenters
• "What is your session about", 300 words; published in programme.
• Notes to committee, 300 words.
• Suitable for: new programmers / teachers / data scientists

Following the suggestions on that CFP, a talk's title and subtitle might be

What I learned building Forth in 64-bit Intel assembly

an excursion into what happens when one quirky language from the 1970s becomes a strange urge and a silly side-project.

(as per the CFP) The goals of this talk are to:

• teach the conference something;
• make the conference laugh;
• broaden the conference's horizons.

It might be described in 300 words thus:

The computer programming language Forth was invented by Charles H. Moore in 1970. Forth is famous for being stack based and using reverse polish notation: the operators come after their operands. A Forth program to convert from Fahrenheit to Celsius (C = (F-32) × 5/9) is:

32 - 5 * 9 /

On 23rd August 2016 I had an urge to write a Forth system in 64-bit Intel Assembly. This talk is about what happens next.

In it I unpack what it means to implement a language. I dig a little into a lower-level description of typical computer hardware, and a little into 64-bit Intel Assembly. Compared to Python, Forth is a low-level language; compared to Assembly, Forth is a high-level language.

I'll talk about how we can implement one language in terms of another, by building models, and how we can model languages and model computational processes.

Forth is a tiny, but powerful, language. Moore's insight was to discover a language that was:

• small;
• sufficient;
• easy to implement;
• extensible.

The result is that Forth implementations are typically composed of a tiny nucleus (typically in Assembly) surrounded by a larger amount of "Forth-in-Forth".

Come. Let's implement a language.

More people should know what's involved in implementing a programming language.

• Forth
• Notation
• Expressing Problems
• Solving Problems using Suitable Notation
• What is a Computer?
• What is a Language?
• What does it mean to Implement a Language?
• A Model for Forth
• Implementing the Model
• Reflecting on the Model
• The Various Layers
• Moving between Layers
• The Bootstrap
• Strategies for Bootstrap