Added alias hacks from frock to lib. See #321.

Thanks @asarhaddon for your guidance.

lib/alias-hacks.mal

@@ -0,0 +1,24 @@
+;; aliases for common clojure names to mal builtins
+;; NOTE: this is a hack
+;; 
+;; Origin: https://github.com/chr15m/frock
+
+; TODO: re-implement as actually useful macros:
+; destructuring, arg checking, etc.
+
+(def! _alias_add_implicit
+  (fn* [special added]
+    (fn* [x & xs]
+      (list special x (cons added xs)))))
+
+(defmacro! let  (_alias_add_implicit 'let* 'do))
+(defmacro! when (_alias_add_implicit 'if   'do))
+(defmacro! def  (_alias_add_implicit 'def! 'do))
+(defmacro! fn   (_alias_add_implicit 'fn*  'do))
+(defmacro! defn (_alias_add_implicit 'def! 'fn))
+
+(def! partial (fn* [pfn & args]
+  (fn* [& args-inner]
+    (apply pfn (concat args args-inner)))))
+
+nil

tests/lib/alias-hacks.mal

@@ -0,0 +1,55 @@
+;; Testing alias-hacks.mal
+(load-file "../../lib/alias-hacks.mal")
+;=>nil
+
+;; Testing let
+(macroexpand (let binds a b))
+;=>(let* binds (do a b))
+(let [x 2] 3 x)
+;=>2
+
+;; Testing when
+(macroexpand (when condition a b))
+;=>(if condition (do a b))
+(when false (nth () 0) a)
+;=>nil
+(when true 3 2)
+;=>2
+
+;; Testing name
+(macroexpand (def name a b))
+;=>(def! name (do a b))
+(def x 1 2 3)
+;=>3
+x
+;=>3
+
+;; Testing fn
+(macroexpand (fn args a b))
+;=>(fn* args (do a b))
+((fn [x] 1 2) 3)
+;=>2
+
+;; Testing defn
+(macroexpand (defn name args b))
+;=>(def! name (fn args b))
+(defn f [x] 1 2 x)
+(f 3)
+;=>3
+
+;; Testing partial
+((partial +) 1 2)
+;=>3
+((partial + 1) 2)
+;=>3
+((partial + 1 2))
+;=>3
+((partial not) false)
+;=>true
+((partial not false))
+;=>true
+((partial (fn* [x y] (+ x y)) 1) 2)
+;=>3
+((partial str 1 2) 3 4)
+;=>"1234"
+