is let keyword necesary?

[fega]

I would be great to remove it, as I saw in the docs, it doesn't looks neccesary.

[ospencer]

It's not technically necessary.

It's more of a developer familiarity thing, since the people who would want to use Grain are probably pretty familiar with JavaScript or an ML language where let is pretty comfortable.

You could definitely argue that Python doesn't require it and gets along just fine (and it would be even more clear in Grain since reassignments aren't allowed without using a box).

It's something to consider, for sure.

[peblair]

Personally, I am a fan of let, as it helps visually clarify the scope in which a variable is defined. Moreover, while Grain does not currently have traditional mutation, sticking with the keyword increases the language's syntactic flexibility on that front in the future.

As @ospencer implies, however, a lot of it really boils down to preference. I don't want to totally count out let-less Grain, but I'm not totally sure we want to take that route at this moment.