Understanding this line from vanilla tick set up

[Mannix]

I'm wondering what this part of the line, it is a conditional does: not min(`time`sym~2#key flip value@)each t

In particular why there is an @ Appy here?

[matt_moore · Accepted solution]

It's creating a unary projection / composition for the part in brackets, could achieve the same with a lamda function:

q)(`time`sym~2#key flip value@)
~[`time`sym]#[2]!+@[.:]
q)(`time`sym~2#key flip value@) each t
110b
q){`time`sym~2#key flip value x} each t
110b

* there is an overhead with using lambdas so in tick it's preferred to be as efficient as possible 

[matt_moore · Accepted solution]

It's creating a unary projection / composition for the part in brackets, could achieve the same with a lamda function:

q)(`time`sym~2#key flip value@)
~[`time`sym]#[2]!+@[.:]
q)(`time`sym~2#key flip value@) each t
110b
q){`time`sym~2#key flip value x} each t
110b

* there is an overhead with using lambdas so in tick it's preferred to be as efficient as possible 

[SJT · Accepted solution]

Where u, v, w, etc. are unaries then u v w@ is a unary composition equivalent to {u v w x}.

In this case two of the five unaries are projections. A little spacing clarifies:

(`time`sym~ 2# key flip value@) each t