Clojurians Log v2

IDeref / IAtom now implementable in user code on sci master: https://twitter.com/borkdude/status/1306206133539999745

Hi I have a little question regarding eval-form. It's said to bind sci/ns with sci/binding . I have try the following which works:

(def program
  '(let [current-ns (-> *ns* str symbol)]
     (ns foo)
     (defn bar [x] (inc x))
     (in-ns current-ns)

     (require 'foo)
     (foo/bar 1)))


(def env (sci/init {}))

(sci/binding [sci/ns sci/ns]
  (sci/eval-form env program))

(vars/with-bindings {vars/current-ns @vars/current-ns}

@jeremys (sci/binding [sci/ns @sci/ns] ...)

so: bind sci/ns to the current value of sci/ns

sci/ns is a sci var, not a normal var, that's why you have to deref is explicitly

the reason for the binding is the same as in clojure: set! is only allowed when there is already a thread-local binding

@jeremys ns switches aren't supported in let forms, only top level or in top-level do:

(require '[sci.core :as sci])

(def program
  '(do (ns foo)
       (defn bar [x] (inc x))
       (ns user)
       (require 'foo)
       (foo/bar 1)))

(def env (sci/init {}))

(sci/binding [sci/ns sci/ns]
  (prn (sci/eval-form env program)))

Note that that doesn't work in normal Clojure either:

(let [current-ns (-> *ns* str symbol)]
  (prn current-ns)
  (ns foo)
  (defn bar [x] (inc x))
  (in-ns current-ns)
  (require 'foo)
  ((resolve 'foo/bar) 1))

but this on the other hand does work:

(do
  (ns foo)
  (defn bar [x] (inc x))
  (in-ns 'user)
  (require 'foo)
  (prn ((resolve 'foo/bar) 1)))

Ok thanks! Having reified environments, eval, macros is pretty powerful but sometimes it is confusing, especially playing with sci witch adds another layer of environment, eval and macros... It's fun though!