Using the constant function

[vinicius98s]

Hello, I recently found the constant function, and I noticed a weird behavior (at least from my point of view, so I might have misunderstood its usage).
So, if you run the following snippet:

import * as O from "fp-ts/Option";
import { constant, pipe } from "fp-ts/function";

pipe(
  O.some("hello"),
  O.fold(constant(console.log("none")), constant(console.log("some")))
)

You will notice that it outputs both "none" and "some" in the terminal.
I thought it would be the same as:

import * as O from "fp-ts/Option";
import { pipe } from "fp-ts/function";

pipe(
  O.some("hello"),
  O.fold(() => console.log("none"), () => console.log("some"))
)

Which just outputs "some", I'm still a little bit confused on why this happens because the constant function returns Lazy<A> function, can someone clarify this?
Thank you

[david-zacharias]

I'd say, you nearly gave the answer by your self: constant function returns Lazy<A>. In your first example the console.log("none") and console.log("some") will be executed instantly and their return values (void in this case) becomes lazy.

[samhh]

It should be noted that console.log can be purely represented with IO, as per the Console module, with which log("none") represents an action but doesn't execute it.

[vinicius98s]

Yeah I see now, for some reason I was thinking that the console.log wouldn't be evaluated, thanks for the clarification