Are there someone who uses the Flambo Spark library? I was planning to learn Spark with Clojure and I'm considering to use Flambo. There was just this problem that when following the Flambo tutorial I immediately got stuck with something (more about it in the #flambo channel). I also git cloned the flambo project and tried to lein test and there were some test errors. How mature is that library? Are there other Clojure Spark libraries?

This? https://gorillalabs.github.io/sparkling/

Are there some experiences regarding Flambo vs Sparkling?

Hi, where's my mistake?

(eval `(let [a# 3] a#))

What doesn't work?

type

`(let [a 3] a)

(the spec error you shortened tells you exactly what is wrong)

ofc I ran it in the repl, the problem is something with a

I was confused with @ghadi’s explanation as well

it’s because the expansion namespaces the a symbol

you get:

(let [user/a 3] user/a)

however, that’s invalid

you can’t create namespaced let bindings

the spec error he was talking about:

user/a - failed: simple-symbol? at: [:bindings :form :local-symbol] spec: :clojure.core.specs.alpha/local-name

(`simple-symbol?` probably means, “isn’t namespaced”)

yes, I also understood that. Solved it using a#

clojure.core/simple-symbol? Return true if x is a symbol without a namespace

I'd argue that that error message is almost perfectly descriptive

It's saying that a value user/a failed that predicate

But that's speaking with some knowledge that macros are checked against specs, and that 'let' is a macro...

When in doubt, deconstruct the problem

Interesting, works fine in Clojure 1.7 😋