Understanding-j: An introduction to the J programming language that gets to the

48 todsacerdoti 9 5/3/2025, 8:40:59 PM github.com ↗

Comments (9)

pixelpoet · 8h ago
The title stops just short of the
johnisgood · 3h ago
"to the point", I presume, based on its README.
pjmlp · 2h ago
A side effect of the small length available for titles and the whole titles should not be editoralised point of view.
jbverschoor · 1h ago
Not the same as (Visual) J++. Great IDE btw
t-writescode · 6h ago
From the doc,

  _3                  NB. negative numbers start with underscore
  _                   NB. sole underscore is infinity: a number
  __                  NB. negative infinity
Is this a standard I'm unaware of?
avmich · 5h ago
The use of underscore for negative numbers is J's choice, explained e.g. here - https://www.jsoftware.com/docs/help807/jforc/preliminaries.h... .

Explicitly representing infinity, and working with it in some cases, allows to reduce number of exceptions...

gitroom · 4h ago
Underscore stuff always throws me off - never quite got used to how J does it. Gotta respect the weird choices though.
prezjordan · 9h ago
To the author: you can add a .devcontainer directory with a Dockerfile, allowing folks to try this in their browser with GitHub Codespaces

Shameless plug, feel free to copy my setup! https://github.com/jdan/try-j

userbinator · 8h ago
Unintentional humour with how the title got cut off?