apply Function Issue

RE: apply Function Issue

Mathieu Drouin — Sat, 10 May 2025 14:54:14 GMT

👀

RE: apply Function Issue

Mike Schmitt — Fri, 09 May 2025 17:27:06 GMT

I did my own little stress test - it looks like in extreme cases (lists of 100,000 items for example), apply() is between 6x and 10x faster than a!forEach(). Probably because apply() is a primitive function and, i'd guess, uses lower-level code. IMHO this trade-off would only matter in ridiculously extreme cases and very very rarely matter in any real-world usage, particularly compared to the complexity and readability trade-off.

RE: apply Function Issue

sanjuktab2257 — Fri, 09 May 2025 17:25:31 GMT

I just did a stress test, a!apply took 4ms where as a!forEach took 21ms

RE: apply Function Issue

sanjuktab2257 — Fri, 09 May 2025 17:20:26 GMT

Thanks Mike!

RE: apply Function Issue

Mike Schmitt — Fri, 09 May 2025 17:18:29 GMT

[quote userid="289109" url="~/discussions/f/user-interface/17245/apply-function-issue/147959"]Is the time complexity of a!apply and a!forEach is same? [/quote]

If you just mean execution time, I've never heard any reputable evidence that a!forEach() is any measurable amount slower than apply(), even in stress tests. But you could always devise your own stress test and compare, I guess.

RE: apply Function Issue

sanjuktab2257 — Fri, 09 May 2025 16:40:10 GMT

Is the time complexity of a!apply and a!forEach is same? or apply is like map function in appian with time complexity O(1)?

RE: apply Function Issue

davel001150 — Mon, 08 Jul 2019 13:59:47 GMT

That's exactly right, Mike. If you include the parentheses, you also have to use partial evaluation to show the code where the array of items are supposed to be input as parameters one at a time.

apply(

rule!myRule,

local!myList

)

does the same thing as

apply(

rule!myRule(_),

local!myList

)

You need the underscore, otherwise you make it look like you're applying a rule with no parameters to a list, which doesn't make any sense.

RE: apply Function Issue

Mike Schmitt — Sat, 06 Jul 2019 03:25:10 GMT

Cool - a!forEach is generally more flexible as well as more powerful while still being easier to understand overall.

As far as why your original code didn't work - my first guess is that when you reference a rule with apply() without specifying parameters, you need to invoke the rule name without the () at the end. so more like this:

apply(
rule!myRule,
local!myList
)

RE: apply Function Issue

aneeshv713 — Sat, 06 Jul 2019 02:42:25 GMT

a!forEach() worked. Thanks.

RE: apply Function Issue

aneeshv713 — Sat, 06 Jul 2019 02:37:41 GMT

No particular reason.

RE: apply Function Issue

Mike Schmitt — Sat, 06 Jul 2019 00:56:46 GMT

Is there any particular reason you're still using apply() instead of a!forEach()?