What is Pometo?

Pometo is the the little APL for the BEAM, an auxiliary language to complement and use in your Erlang, Elixir and LFE applications.

Status Of The Project

THIS PROJECT IS SUPER-EARLY, NOT SO MUCH ALPHA AS BEFORE THE DAWN OF WRITING, SOME INCHOATE SYMBOLS SCRAWLED WITH A HALF-BURNT STICK ON A CAVE WALL.

           _       _
     /\   | |     | |
    /  \  | |_ __ | |__   __ _
   / /\ \ | | '_ \| '_ \ / _` |
  / ____ \| | |_) | | | | (_| |
 /_/__  \_\_| .__/|_| |_|\__,_|_____                    ____        _      __
  / / |     | |               |  __ \                  / __ \      | |     \ \
 | || |     |_|_ _ __   __ _  | |  | | _____   _____  | |  | |_ __ | |_   _ | |
 | || |    / _` | '_ \ / _` | | |  | |/ _ \ \ / / __| | |  | | '_ \| | | | || |
 | || |___| (_| | | | | (_| | | |__| |  __/\ V /\__ \ | |__| | | | | | |_| || |
 | ||______\__,_|_| |_|\__, | |_____/ \___| \_/ |___/  \____/|_| |_|_|\__, || |
  \_\                   __/ |                                          __/ /_/
                       |___/                                          |___/

Pometo is a long way from being production usable - but if you want to help us get there, pile in.

Why is it called Pometo?

Pometo is the Esperanto for little apple and Pometo is a little APL and Esperanto words are both easily pronounceable and usually available as domains.

Why Pometo?

There are some problems that are elegantly solved with an APL syntax and Pometo is designed to write short, concise programmes that can be reasoned about to solve those problems.

Writing supervision trees and gen servers are not problems in that category.

Pometo is an auxiliary language - used to write library functions which are consumed in applications not written in Pometo.

Read more about the rationale and thinking.

Design Considerations

The normal developer of Erlang, Elixir and LFE applications should not know they are calling Pometo without reading the source code.

Pometo libraries will be listed on hex, they will use rebar3 to build. The data structures in Pometo will be lists and maps, the data-types integers, floats, binaries and atoms.

Contributing To Pometo

APL’s traditionally have a REPL and the Pometo one is a standalone web application called rappel.

rappel is the runner in which development takes place.

If you wish to help develop Pometo you should install rappel.

The rappel github repository has instructions for how to get up and running with rappel and Pometo and start contributing code.

You can find Rappel on github

Pometo uses two rebar3 plugins called pometo_docs_to_tests and pometo_docs_to_ct_tests to turn the documentation into Eunit and Common tests respectively.

You can find the Pometo Docs To CT Tests plugin on github

You can find the Pometo Docs To Tests plugin on github

There are pages in the Implementation Reference to help you get up and running as contributors to Pometo.

We are implementing a funded Open Source Maintainers programme in conjunction with Code Your Future. CodeYourFuture is a refugee-founded and lead programme that trains disadvantaged people in software development.

The OSM programme is a post-graduation, pre-formal job transition that gives CYF graduates real world experience of software development in the wild. Because OSM contributors have no previous experience of Erlang, or Elixir or an APL this programme has a set of getting-started tasks defined.

(People who are not on the OSM programme are very welcome to ride along with the OSM introduction, but please don’t just grab tasks off the OSM list without saying hello to the core team first.)

Please read our Code of Conduct.

Contents

User Documentation

• APL For Erlang And Elixir Programmers
• Data Types
• Variables
• Comments

Technical Reference

• The Replicate Functions / and ⌿
• The Identity/Complex Conjugate/Plus Function +
• The Negation/Minus Function -
• The Direction/Multiply Function ×
• The Reciprocal/Divide Function ÷
• The Rho/Shape Function ⍴
• The Iota/Index Function ⍳
• The Ravel/Comma Function ,
• The Reduce Operators / And ⌿

StdLib Reference

• The ⎕debug Function
• The ⎕print_trees Function
• The ⎕make_indexed Function
• The ⎕make_lazy Function
• The ⎕force_indexing Function
• The ⎕force_unindexing Function

Errors Reference

• Alphabetical List Of Errors

Implementation Reference

• Exploring The Runtime Parse Tree
• Implementation Details Of Complex Numbers
• Smoke Tests

For Contributors To (And Developers Of) Pometo

• Pometo Contributors Code Of Conduct
• Getting Started As An Open Source Maintainer Of Pometo
• Documentation Of The Erlang Code
• The Language Roadmap
• Our Development Environment
• Eek, How Do I Even Type This?
• The Development Cycle
• Our Testing
• The Toolchain And Testing
• The REPL (Read-Evaluate-Print-Loop) Rappel
• Lexer/Parser Development