Concatenative Programming

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Hello!

This space is for sharing news, experiences, announcements, questions, showcases, etc. regarding concatenative programming concepts and tools.

We'll also take any programming described as:


From Wikipedia:

A concatenative programming language is a point-free computer programming language in which all expressions denote functions, and the juxtaposition of expressions denotes function composition. Concatenative programming replaces function application, which is common in other programming styles, with function composition as the default way to build subroutines.

For example, a sequence of operations in an applicative language like the following:

y = foo(x)
z = bar(y)
w = baz(z)

...is written in a concatenative language as a sequence of functions:

x foo bar baz


Active Languages

Let me know if I've got any of these misplaced!

Primarily Concatenative

Concatenative-ish, Chain-y, Pipe-y, Uniform Function Call Syntax, etc.


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F: Functional False (www.nsl.com)
submitted 4 months ago* (last edited 4 months ago) by Andy@programming.dev to c/concatenative@programming.dev
 
 

F is a pure functional concatenative language originally designed as an extension of False. F contains the list-operations of K3 and the dip combinator of Joy. Floating-point and symbolic datatypes are supported. One-time assignment is enforced in syntax. A theory of function-valence and -charge is outlined. F also contains a general continuation primitive $, and the pattern sublanguage of XY. G is a variant of F in which the K3 adverbs are implemented as primitives.

Discussion on lobsters: https://lobste.rs/s/m9xv5y/f_functional_false

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Factor gains a quit function (and preserves history)!

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This is already in the sidebar, but now there's a fresh post on Lobsters, so maybe some good discussion will come of it.

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0.1 + 0.2 | Roc (rtfeldman.com)
submitted 4 months ago* (last edited 4 months ago) by Andy@programming.dev to c/concatenative@programming.dev
 
 

Discussion on lobsters: https://lobste.rs/s/oxjvv0/0_1_0_2

It's not that Roc only supports base-10 arithmetic. It also supports the typical base-2 floating-point numbers, because in many situations the performance benefits are absolutely worth the cost of precision loss. What sets Roc apart is its choice of default; when you write decimal literals like 0.1 or 0.2 in Roc, by default they're represented by a 128-bit fixed-point base-10 number that never loses precision, making it reasonable to use for calculations involving money.

In Roc, floats are opt-in rather than opt-out.

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From the STOMP homepage:

What is it?

STOMP is the Simple (or Streaming) Text Orientated Messaging Protocol.

STOMP provides an interoperable wire format so that STOMP clients can communicate with any STOMP message broker to provide easy and widespread messaging interoperability among many languages, platforms and brokers.

Simple Design

STOMP is a very simple and easy to implement protocol, coming from the HTTP school of design; the server side may be hard to implement well, but it is very easy to write a client to get yourself connected. For example you can use Telnet to login to any STOMP broker and interact with it!

From John's blog post:

In the interest of learning Factor, I thought I would write a bit about parsing the STOMP protocol, and then about how to implement a client library using connection-oriented networking, interacting with it using mailboxes, and then building a command-line interface using the command-loop vocabulary.

There are many STOMP servers and clients available in different languages. I tried a few and decided that Apache ActiveMQ was one of the most convenient to setup and reliable to work with, but others are available as well.

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Discussion on lobsters

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Discussion on lobsters

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John B's blog post calls it:

. . . a pretty neat hour long introduction going over a lot of features that users new to the language might be interested in.

The video creator's description:

This is an introductory tutorial for a stack-based (concatenative) programming language Factor. It covers some basic language constructs and a few features of the interactive development environment that is shipped with Factor.

I've re-shot my two prior recordings combining everything into a single video.

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I don't yet have a feel for any key differences between pql and PRQL.

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Copied from the readme:


cosh is a concatenative command-line shell.

Why?

Basic shell operations like ls, ps, stat, and so on are implemented as functions that return first-class values, as opposed to relying on executables that return text streams. This makes working with the results simpler:

  • Find file paths matching a string, and search those files for data

sh:

find . -iname '*test*' -print0 | xargs -0 grep data

cosh:

lsr; [test m] grep; [f<; [data m] grep] map
  • Find all processes using more than 500M of memory:

sh:

ps --no-headers aux | awk '$6>500000'

cosh:

ps; [mem get; 1000 1000 *; 500 *; >] grep

A small set of versatile primitives means that less needs to be remembered when compared with typical shells (see e.g. the various flags for cut(1)), though some commands may be longer as a result:

  • Get the second and third columns from each row of a CSV file:

sh:

cut -d, -f2,3 test-data/csv

cosh:

test-data/csv f<; [chomp; , split; (1 2) get] map
  • Sort files by modification time:

sh:

ls -tr

cosh:

ls; [[stat; mtime get] 2 apply; <=>] sortp

Arithmetical operators and XML/JSON/CSV encoding/decoding functions reduce the number of times that it becomes necessary to use a more full-featured programming language or a third-party executable:

  • Increment floating-point numbers in file:

sh:

sed 's/$/+10/' nums | bc

cosh:

nums f<; [chomp; 10 +] map
  • Get the first value from the "zxcv" array member of a JSON file:

sh:

jq .zxcv[0] test-data/json2

cosh:

test-data/json2 f<; from-json; zxcv get; 0 get

It also integrates with external executable calls, where that is necessary:

  • Print certificate data:

bash:

for i in `find . -iname '*.pem'`; do openssl x509 -in $i -text -noout; done

cosh:

lsr; [pem$ m] grep; [{openssl x509 -in {} -text -noout}] map;

See the full documentation for more details.

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