levand

So, I was having a twitter discussion with the esteemed @alandipert and @swannodette that has gone beyond the scope of what can be effectively communicated in 140 characters.

It was on the perceived value of Clojure's new feature expressions and whether they are worth the complexity cost of adding to Clojure and all its dialects.

Alan's contention (and forgive me if I am misconstruing this, Alan) is that feature expressions make the Clojure reader considerably more complex, and so it becomes that much more difficult to write any software which reads Clojure code (except for Clojure's own reader, of course, where the work is already done). As best I understand Alan's argument, this is a significant enough effect to undermine or negate the value proposition of Feature Expressions all together.

I disagree, so I'd like to go through the pros and cons of each use case.

• Application developers (single-platform codebase): No impact.
• Application developers (multi-platform codebase): FX are strictly easier to u

levand

(deftype MyCountable [delegate]

  #+clj clojure.lang.Counted  #+cljs ICounted
  #+clj (count [_] (.count delegate))
  #+cljs (-count [_] (-count delegate)))

levand

;;profiles.clj
{:user {:repositories {"my.datomic.com" {:url "https://my.datomic.com/repo"
                                         :username "luke@cognitect.com"
                                         :password "MY SUPER SECRET PASSWORD"}}}}

levand

### Keybase proof

I hereby claim:

  * I am levand on github.
  * I am vanderhart (https://keybase.io/vanderhart) on keybase.
  * I have a public key whose fingerprint is 033A 1E51 4A22 2CC4 5C34  E6C2 F8E0 3980 F58B C1B7

To claim this, I am signing this object:

levand

#my/str [
"The first line"
"The second line"
"The third line"
]

levand

 # all indexes are 0-based                                                   
  2 def page_map(page, count, vidaas_count = 20)                                
  3                                                                             
  4   start_idx = page * count                                                  
  5                                                                             
  6   first_page = start_idx / vidaas_count                                     
  7   last_page = first_page + (count / vidaas_count)                           
  8                                                                             
  9   start_offset = start_idx % vidaas_count                                   
 10   end_offset = start_idx + count                                            

levand

  1 # all indexes are 0-based                                                   
  2 def page_map(page, count, vidaas_count = 20)                                
  3                                                                             
  4   start_idx = page * count                                                  
  5                                                                             
  6   first_page = start_idx / vidaas_count                                     
  7   last_page = first_page + (count / vidaas_count)                           
  8                                                                             
  9   start_subset = start_idx % vidaas_count                                   
 10   end_subset = start_subset + count                                         

levand

def page_map(page, count, vidaas_count = 20)  
  start_idx = page * count                                                  

  first_page = start_idx / vidaas_count
  last_page = first_page + (count / vidaas_count)

  start_subset = start_idx % vidaas_count
  end_subset = start_subset + count

levand

;; Both of these code samples do exactly the same thing: define an asset pipeline
;; with a ClojureScript build that reads from "src/cljs/*" and compiles to "out/*".
;;The question is, which style of DSL is more readable/natural?

(require '[arachne.assets.dsl :as a])
(require '[arachne.cljs.dsl :as cljs])

(def opts {:output-to "js/main.js"
           :output-dir "js"
           :asset-path "js"

levand

(def opts {:output-to "main.js"
           :asset-path "js"
           :output-dir "js"
           :optimizations :none
           :main 'arachne.cljs.example})

(a/input-dir :test/input {:dir "src/cljs" :watch? false})
(cljs/build :test/build {:compiler-options opts})
(a/output-dir :test/output {:dir "out"})