Add as-> macro (#462)

src/sci/impl/analyzer.cljc

@@ -24,7 +24,7 @@
 (def special-syms '#{try finally do if new recur quote catch throw def . var set!})
 
 ;; Built-in macros.
-(def macros '#{do if and or as-> let fn fn* def defn
+(def macros '#{do if and or let fn fn* def defn
                comment loop lazy-seq for doseq case try defmacro
                declare expand-dot* expand-constructor new . import in-ns ns var
                set! resolve macroexpand-1 macroexpand})
@@ -290,16 +290,6 @@
   (let [let-bindings (destructure let-bindings)]
     (expand-let* ctx let-bindings exprs)))
 
-(defn expand-as->
-  "The ->> macro from clojure.core."
-  [ctx [_as expr nm & forms]]
-  (let [[let-bindings & body] `([~nm ~expr
-                                 ~@(interleave (repeat nm) (butlast forms))]
-                                ~(if (empty? forms)
-                                   nm
-                                   (last forms)))]
-    (expand-let* ctx let-bindings body)))
-
 (declare expand-declare)
 
 (defn expand-def
@@ -684,8 +674,6 @@
                 (defn defmacro) (let [ret (expand-defn ctx expr)]
                                   ret)
                 ;; TODO: implement as normal macro in namespaces.cljc
-                as-> (expand-as-> ctx expr)
-                ;; TODO: implement as normal macro in namespaces.cljc
                 comment (expand-comment ctx expr)
                 loop (expand-loop ctx expr)
                 lazy-seq (expand-lazy-seq ctx expr)

src/sci/impl/namespaces.cljc

@@ -79,6 +79,13 @@
         (recur threaded (next forms)))
       x)))
 
+(defn as->*
+  [_ _ expr name & forms]
+  `(let [~name ~expr
+         ~@(interleave (repeat name) (butlast forms))]
+     ~(if (empty? forms)
+        name
+        (last forms))))
 (defn dotimes*
   [_ _ bindings & body]
   (assert (vector? bindings))
@@ -721,6 +728,7 @@
    '== (copy-core-var ==)
    '-> (macrofy ->*)
    '->> (macrofy ->>*)
+   'as-> (macrofy as->*)
    'add-watch (copy-core-var add-watch)
    'remove-watch (copy-core-var remove-watch)
    'aget (copy-core-var aget)