Understanding and Decoding the anyeach Function in kdb+/q

Community Support
1

Hi everyone,

I’m trying to deconstruct a somewhat cryptic kdb+/q function written by a senior developer at my company. Here’s the function:

anyeach:{[c;v] enlist (each; any; ((:; in); ($; enlist `; (each; { $[“;” in x; “;” vs x; x] }; ($:; c))); (enlist v)))}

I am using like this:

t:( column:(“aaa;bbb”; “aaa”; “ccc;bbb;ddd”));
val:“aaa”;

Here, column is passed as c, and val as v.

My goal is to better understand how the function works—what each part does, step by step. Please help me.

2

Hi Kaviya, it’s likely a typo (or a formatting glitch), should be (\:;in). With t`column and val also fixed by casting them to symbols. Without a usage example, it is hard to confirm but the function seems to be the following filtering

q)?[t;anyeach[`column;val];0b;()]
column
-------
aaa;bbb
aaa