Aplette: a minimalist APL oriented toward scripting within a UNIX environment | Hacker News Reader

Aplette: a minimalist APL oriented toward scripting within a UNIX environment

github.com

69 pointskick7 comments

Does anyone have examples of use to share?

The .inp files in the qa directory seem to be the only samples. The user guide looks mostly reference.

Note to anyone posting a new language experiment: samples are critical!

https://github.com/gregfjohnson/aplette/blob/master/qa/print...

I would like to add that keeping samples up to date is important too. In the early days there may be breaking changes, I should always be able to run the samples with the latest version of the language and not get any errors or end up with unexpected behavior.

Over the weekend I was trying to figure out the perspective transformation in a 3D graphics package (THREE.js). 3D graphics involves a lot of matrix algebra, and so is ideal for APL. Here is an aplette function for creating a perspective matrix:

  G m { gfx parms; left; right; bottom; top; near; far
  left { parms[1]
  right { parms[2]
  bottom { parms[3]
  top { parms[4]
  near { parms[5]
  far { parms[6]
  m { 4 4R0
  m[1;1] { 2 X near % (right-left)
  m[1;3] { (right + left) % (right - left)
  m[2;2] { 2 X near % (top-bottom)
  m[2;3] { (top + bottom) % (top - bottom)
  m[3;3] { -(far + near) % (far - near)
  m[3;4] { -2 X far X near % (far - near)
  m[4;3] { `1

        )read gfx
        m { gfx `10 10 `10 10 2 1000
  8 4 J@N m
  0.2000  0.0000  0.0000  0.0000
  0.0000  0.2000  0.0000  0.0000
  0.0000  0.0000 `1.0040 `4.0080
  0.0000  0.0000 `1.0000  0.0000

 8 4 J@N %@L m
  5.0000  0.0000  0.0000  0.0000
  0.0000  5.0000  0.0000  0.0000
  0.0000  0.0000  0.0000 `1.0000
  0.0000  0.0000 `0.2495  0.2505

Thanks for the feedback! I appreciate it. I will revisit the qa directory, and also add a samples directory. I added an APL command that you may enjoy, related to the issue of examples. ")font" will print a nicely formatted two-column summary of all APL commands, together with the "APL touchtype font" versions of those commands.

Glad to see you're still around! Do you post your code anywhere these days?

I use github to post code, and also as a convenient way to copy work in progress from machine to machine. I just updated https://github.com/gregfjohnson/rubik, a fun javascript hack that supports interactive simulation and solving of 3x3 Rubik's cubes. (deployed at http://gregfjohnson.com/rubik)

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