Re: [Bug-apl] Feature suggestion: multiple function arguments

[Louis de Forcrand]

To add to the confusion, while

(  {+⌿ ÷ ≢} y) ≡ ( +⌿y) ÷  ≢y

(x {+⌿ ÷ ≢} y) ≡ (x+⌿y) ÷ x≢y

whatever that does.

I completely agree, it’s quite obscure, especially if one is not accustomed to

tacit definition. This by the way is a fork, and is basically a way to avoid

parentheses. More useful however is the bonding operator, which I know

is functional in Dyalog:

toCelsius ←((5÷9)∘×)∘(-∘32)

toFahrenheit ←toCelsius⍣¯1

toFahr toCelsius 212

212

Which can be very handy.

Louis

On 05 Mar 2016, at 16:33, Elias Mårtenson <address@hidden> wrote:

On 5 March 2016 at 23:28, Louis de Forcrand <address@hidden> wrote:

That would be a great idea. However, it would indeed take not only quite a bit of

time to set up, but would also need constant checking to make sure the updates

in the main branch don’t conflict with additions.

While I just said that I believe the main branch should probably concentrate on

the standard, one of the things I’ve really fallen in love with in J and that is

completely missing in standard APL is tacit definition. Not only does it allow

inversible functions and idiom detection for optimisation, but it is just simply

so elegant:

mean ← +⌿ ÷ ≢

This is where we disagree, but nothing wrong with that. I can certainly understand why someone would like that construct, but I just don't like it at all. I think this is probably the least clear and easily the most confusing language construct I know of in any language I have tried.

I would certainly like to see some simpler way to define such functions without multiple levels of lambda definitions, but the J model is not the right way, in my opinion.

Regards,

Elias