From 0d842530928b41c0ef904df8190524f253c8931a Mon Sep 17 00:00:00 2001
From: rhysd <lin90162@yahoo.co.jp>
Date: Thu, 4 Jun 2015 00:39:48 +0900
Subject: [PATCH] rename mal to crisp

---
 src/core.cr                    |  94 ++++++------
 src/{stepA_mal.cr => crisp.cr} | 112 +++++++-------
 src/env.cr                     |  16 +-
 src/error.cr                   |   6 +-
 src/printer.cr                 |  18 +--
 src/reader.cr                  |  20 +--
 src/step0_repl.cr              |  26 ----
 src/step1_read_print.cr        |  32 ----
 src/step2_eval.cr              |  90 -----------
 src/step3_env.cr               | 115 --------------
 src/step4_if_fn_do.cr          | 130 ----------------
 src/step5_tco.cr               | 164 --------------------
 src/step6_file.cr              | 177 ---------------------
 src/step7_quote.cr             | 207 -------------------------
 src/step8_macros.cr            | 253 ------------------------------
 src/step9_try.cr               | 270 ---------------------------------
 src/types.cr                   |   8 +-
 17 files changed, 136 insertions(+), 1602 deletions(-)
 rename src/{stepA_mal.cr => crisp.cr} (65%)
 delete mode 100755 src/step0_repl.cr
 delete mode 100755 src/step1_read_print.cr
 delete mode 100755 src/step2_eval.cr
 delete mode 100755 src/step3_env.cr
 delete mode 100755 src/step4_if_fn_do.cr
 delete mode 100755 src/step5_tco.cr
 delete mode 100755 src/step6_file.cr
 delete mode 100755 src/step7_quote.cr
 delete mode 100755 src/step8_macros.cr
 delete mode 100755 src/step9_try.cr

diff --git a/src/core.cr b/src/core.cr
index 15f870d..637cd54 100644
--- a/src/core.cr
+++ b/src/core.cr
@@ -6,22 +6,22 @@ require "./printer"
 require "./reader"
 require "./readline"
 
-module Mal
+module Crisp
 
 macro calc_op(op)
-  -> (args : Array(Mal::Type)) {
+  -> (args : Array(Crisp::Type)) {
     x, y = args[0].unwrap, args[1].unwrap
     eval_error "invalid arguments for binary operator {{op.id}}" unless x.is_a?(Int32) && y.is_a?(Int32)
-    Mal::Type.new(x {{op.id}} y)
+    Crisp::Type.new(x {{op.id}} y)
   }
 end
 
 def self.list(args)
-  args.to_mal
+  args.to_crisp_value
 end
 
 def self.list?(args)
-  args.first.unwrap.is_a? Mal::List
+  args.first.unwrap.is_a? Crisp::List
 end
 
 def self.empty?(args)
@@ -76,13 +76,13 @@ def self.slurp(args)
 end
 
 def self.cons(args)
-  head, tail = args[0] as Mal::Type, args[1].unwrap
+  head, tail = args[0] as Crisp::Type, args[1].unwrap
   eval_error "2nd arg of cons must be list" unless tail.is_a? Array
-  ([head] + tail).to_mal
+  ([head] + tail).to_crisp_value
 end
 
 def self.concat(args)
-  args.each_with_object(Mal::List.new) do |arg, list|
+  args.each_with_object(Crisp::List.new) do |arg, list|
     a = arg.unwrap
     eval_error "arguments of concat must be list" unless a.is_a?(Array)
     a.each{|e| list << e}
@@ -107,10 +107,10 @@ end
 def self.rest(args)
   a0 = args[0].unwrap
 
-  return Mal::List.new if a0.nil?
+  return Crisp::List.new if a0.nil?
   eval_error "1st argument of first must be list or vector or nil" unless a0.is_a? Array
-  return Mal::List.new if a0.empty?
-  a0[1..-1].to_mal
+  return Crisp::List.new if a0.empty?
+  a0[1..-1].to_crisp_value
 end
 
 def self.apply(args)
@@ -122,9 +122,9 @@ def self.apply(args)
   eval_error "last argument of apply must be list or vector" unless last.is_a? Array
 
   case head
-  when Mal::Closure
+  when Crisp::Closure
     head.fn.call(args[1..-2] + last)
-  when Mal::Func
+  when Crisp::Func
     head.call(args[1..-2] + last)
   else
     eval_error "1st argument of apply must be function or closure"
@@ -138,12 +138,12 @@ def self.map(args)
   eval_error "2nd argument of map must be list or vector" unless list.is_a? Array
 
   f = case func
-      when Mal::Closure then func.fn
-      when Mal::Func    then func
+      when Crisp::Closure then func.fn
+      when Crisp::Func    then func
       else                   eval_error "1st argument of map must be function"
       end
 
-  list.each_with_object(Mal::List.new) do |elem, mapped|
+  list.each_with_object(Crisp::List.new) do |elem, mapped|
     mapped << f.call([elem])
   end
 end
@@ -163,13 +163,13 @@ def self.false?(args)
 end
 
 def self.symbol?(args)
-  args.first.unwrap.is_a?(Mal::Symbol)
+  args.first.unwrap.is_a?(Crisp::Symbol)
 end
 
 def self.symbol(args)
   head = args.first.unwrap
   eval_error "1st argument of symbol function must be string" unless head.is_a? String
-  Mal::Symbol.new head
+  Crisp::Symbol.new head
 end
 
 def self.keyword(args)
@@ -184,16 +184,16 @@ def self.keyword?(args)
 end
 
 def self.vector(args)
-  args.to_mal(Mal::Vector)
+  args.to_crisp_value(Crisp::Vector)
 end
 
 def self.vector?(args)
-  args.first.unwrap.is_a? Mal::Vector
+  args.first.unwrap.is_a? Crisp::Vector
 end
 
 def self.hash_map(args)
   eval_error "hash-map must take even number of arguments" unless args.size.even?
-  map = Mal::HashMap.new
+  map = Crisp::HashMap.new
   args.each_slice(2) do |kv|
     k = kv[0].unwrap
     eval_error "key must be string" unless k.is_a? String
@@ -203,15 +203,15 @@ def self.hash_map(args)
 end
 
 def self.map?(args)
-  args.first.unwrap.is_a? Mal::HashMap
+  args.first.unwrap.is_a? Crisp::HashMap
 end
 
 def self.assoc(args)
   head = args.first.unwrap
-  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Mal::HashMap
+  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Crisp::HashMap
   eval_error "assoc must take a list and even number of arguments" unless (args.size - 1).even?
 
-  map = Mal::HashMap.new
+  map = Crisp::HashMap.new
   head.each{|k, v| map[k] = v}
 
   args[1..-1].each_slice(2) do |kv|
@@ -225,9 +225,9 @@ end
 
 def self.dissoc(args)
   head = args.first.unwrap
-  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Mal::HashMap
+  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Crisp::HashMap
 
-  map = Mal::HashMap.new
+  map = Crisp::HashMap.new
   head.each{|k,v| map[k] = v}
 
   args[1..-1].each do |arg|
@@ -241,7 +241,7 @@ end
 
 def self.get(args)
   a0, a1 = args[0].unwrap, args[1].unwrap
-  return nil unless a0.is_a? Mal::HashMap
+  return nil unless a0.is_a? Crisp::HashMap
   eval_error "2nd argument of get must be string" unless a1.is_a? String
 
   # a0[a1]? isn't available because type ofa0[a1] is infered NoReturn
@@ -250,21 +250,21 @@ end
 
 def self.contains?(args)
   a0, a1 = args[0].unwrap, args[1].unwrap
-  eval_error "1st argument of get must be hashmap" unless a0.is_a? Mal::HashMap
+  eval_error "1st argument of get must be hashmap" unless a0.is_a? Crisp::HashMap
   eval_error "2nd argument of get must be string" unless a1.is_a? String
   a0.has_key? a1
 end
 
 def self.keys(args)
   head = args.first.unwrap
-  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Mal::HashMap
-  head.keys.each_with_object(Mal::List.new){|e,l| l << Mal::Type.new(e)}
+  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Crisp::HashMap
+  head.keys.each_with_object(Crisp::List.new){|e,l| l << Crisp::Type.new(e)}
 end
 
 def self.vals(args)
   head = args.first.unwrap
-  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Mal::HashMap
-  head.values.to_mal
+  eval_error "1st argument of assoc must be hashmap" unless head.is_a? Crisp::HashMap
+  head.values.to_crisp_value
 end
 
 def self.sequential?(args)
@@ -289,36 +289,36 @@ def self.with_meta(args)
 end
 
 def self.atom(args)
-  Mal::Atom.new args.first
+  Crisp::Atom.new args.first
 end
 
 def self.atom?(args)
-  args.first.unwrap.is_a? Mal::Atom
+  args.first.unwrap.is_a? Crisp::Atom
 end
 
 def self.deref(args)
   head = args.first.unwrap
-  eval_error "1st argument of deref must be atom" unless head.is_a? Mal::Atom
+  eval_error "1st argument of deref must be atom" unless head.is_a? Crisp::Atom
   head.val
 end
 
 def self.reset!(args)
   head = args.first.unwrap
-  eval_error "1st argument of reset! must be atom" unless head.is_a? Mal::Atom
+  eval_error "1st argument of reset! must be atom" unless head.is_a? Crisp::Atom
   head.val = args[1]
 end
 
 def self.swap!(args)
   atom = args.first.unwrap
-  eval_error "1st argument of swap! must be atom" unless atom.is_a? Mal::Atom
+  eval_error "1st argument of swap! must be atom" unless atom.is_a? Crisp::Atom
 
   a = [atom.val] + args[2..-1]
 
   func = args[1].unwrap
   case func
-  when Mal::Func
+  when Crisp::Func
     atom.val = func.call a
-  when Mal::Closure
+  when Crisp::Closure
     atom.val = func.fn.call a
   else
     eval_error "2nd argumetn of swap! must be function"
@@ -328,10 +328,10 @@ end
 def self.conj(args)
   seq = args.first.unwrap
   case seq
-  when Mal::List
-    (args[1..-1].reverse + seq).to_mal
-  when Mal::Vector
-    (seq + args[1..-1]).to_mal(Mal::Vector)
+  when Crisp::List
+    (args[1..-1].reverse + seq).to_crisp_value
+  when Crisp::Vector
+    (seq + args[1..-1]).to_crisp_value(Crisp::Vector)
   else
     eval_error "1st argument of conj must be list or vector"
   end
@@ -344,11 +344,11 @@ end
 # Note:
 # Simply using ->self.some_func doesn't work
 macro func(name)
-  -> (args : Array(Mal::Type)) { Mal::Type.new self.{{name.id}}(args) }
+  -> (args : Array(Crisp::Type)) { Crisp::Type.new self.{{name.id}}(args) }
 end
 
 macro rel_op(op)
--> (args : Array(Mal::Type)) { Mal::Type.new (args[0] {{op.id}} args[1]) }
+-> (args : Array(Crisp::Type)) { Crisp::Type.new (args[0] {{op.id}} args[1]) }
 end
 
 NS = {
@@ -376,7 +376,7 @@ NS = {
   "nth"         => func(:nth)
   "first"       => func(:first)
   "rest"        => func(:rest)
-  "throw"       => -> (args : Array(Mal::Type)) { raise Mal::RuntimeException.new args[0] }
+  "throw"       => -> (args : Array(Crisp::Type)) { raise Crisp::RuntimeException.new args[0] }
   "apply"       => func(:apply)
   "map"         => func(:map)
   "nil?"        => func(:nil?)
@@ -408,6 +408,6 @@ NS = {
   "swap!"       => func(:swap!)
   "conj"        => func(:conj)
   "time-ms"     => func(:time_ms)
-} of String => Mal::Func
+} of String => Crisp::Func
 
 end
diff --git a/src/stepA_mal.cr b/src/crisp.cr
similarity index 65%
rename from src/stepA_mal.cr
rename to src/crisp.cr
index 49361ef..edd6019 100755
--- a/src/stepA_mal.cr
+++ b/src/crisp.cr
@@ -14,30 +14,30 @@ require "./error"
 # Employed downcase names because Crystal prohibits uppercase names for methods
 
 def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
+  -> (args : Array(Crisp::Type)) {
+    new_env = Crisp::Env.new(env, binds, args)
     eval(body, new_env)
-  } as Mal::Func
+  } as Crisp::Func
 end
 
 def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Array
+  return ast.map{|n| eval(n, env) as Crisp::Type} if ast.is_a? Array
 
   val = ast.unwrap
 
-  Mal::Type.new case val
-  when Mal::Symbol
+  Crisp::Type.new case val
+  when Crisp::Symbol
     if e = env.get(val.str)
       e
     else
       eval_error "'#{val.str}' not found"
     end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Mal::HashMap
-    new_map = Mal::HashMap.new
+  when Crisp::List
+    val.each_with_object(Crisp::List.new){|n, l| l << eval(n, env)}
+  when Crisp::Vector
+    val.each_with_object(Crisp::Vector.new){|n, l| l << eval(n, env)}
+  when Crisp::HashMap
+    new_map = Crisp::HashMap.new
     val.each{|k, v| new_map[k] = eval(v, env)}
     new_map
   else
@@ -57,8 +57,8 @@ def quasiquote(ast)
   list = ast.unwrap
 
   unless pair?(list)
-    return Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "quote") << ast
+    return Crisp::Type.new(
+      Crisp::List.new << gen_type(Crisp::Symbol, "quote") << ast
     )
   end
 
@@ -66,29 +66,29 @@ def quasiquote(ast)
 
   case
   # ("unquote" ...)
-  when head.is_a?(Mal::Symbol) && head.str == "unquote"
+  when head.is_a?(Crisp::Symbol) && head.str == "unquote"
     list[1]
   # (("splice-unquote" ...) ...)
-  when pair?(head) && (arg0 = head.first.unwrap).is_a?(Mal::Symbol) && arg0.str == "splice-unquote"
-    tail = Mal::Type.new list[1..-1].to_mal
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "concat") << head[1] << quasiquote(tail)
+  when pair?(head) && (arg0 = head.first.unwrap).is_a?(Crisp::Symbol) && arg0.str == "splice-unquote"
+    tail = Crisp::Type.new list[1..-1].to_crisp_value
+    Crisp::Type.new(
+      Crisp::List.new << gen_type(Crisp::Symbol, "concat") << head[1] << quasiquote(tail)
     )
   else
-    tail = Mal::Type.new list[1..-1].to_mal
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
+    tail = Crisp::Type.new list[1..-1].to_crisp_value
+    Crisp::Type.new(
+      Crisp::List.new << gen_type(Crisp::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
     )
   end
 end
 
 def macro_call?(ast, env)
   list = ast.unwrap
-  return false unless list.is_a? Mal::List
+  return false unless list.is_a? Crisp::List
   return false if list.empty?
 
   sym = list.first.unwrap
-  return false unless sym.is_a? Mal::Symbol
+  return false unless sym.is_a? Crisp::Symbol
 
   func = env.find(sym.str).try(&.data[sym.str])
   return false unless func && func.macro?
@@ -100,14 +100,14 @@ def macroexpand(ast, env)
   while macro_call?(ast, env)
 
     # Already checked in macro_call?
-    list = ast.unwrap as Mal::List
-    func_sym = list[0].unwrap as Mal::Symbol
+    list = ast.unwrap as Crisp::List
+    func_sym = list[0].unwrap as Crisp::Symbol
     func = env.get(func_sym.str).unwrap
 
     case func
-    when Mal::Func
+    when Crisp::Func
       ast = func.call(list[1..-1])
-    when Mal::Closure
+    when Crisp::Closure
       ast = func.fn.call(list[1..-1])
     else
       eval_error "macro '#{func_sym.str}' must be function: #{ast}"
@@ -122,11 +122,11 @@ macro invoke_list(l, env)
   args = eval_ast({{l}}[1..-1], {{env}}) as Array
 
   case f
-  when Mal::Closure
+  when Crisp::Closure
     ast = f.ast
-    {{env}} = Mal::Env.new(f.env, f.params, args)
+    {{env}} = Crisp::Env.new(f.env, f.params, args)
     next # TCO
-  when Mal::Func
+  when Crisp::Func
     return f.call args
   else
     eval_error "expected function as the first argument: #{f}"
@@ -141,24 +141,24 @@ def eval(ast, env)
   # 'next' in 'do...end' has a bug in crystal 0.7.1
   # https://github.com/manastech/crystal/issues/659
   while true
-    return eval_ast(ast, env) unless ast.unwrap.is_a? Mal::List
+    return eval_ast(ast, env) unless ast.unwrap.is_a? Crisp::List
 
     ast = macroexpand(ast, env)
 
     list = ast.unwrap
 
-    return ast unless list.is_a? Mal::List
+    return ast unless list.is_a? Crisp::List
     return ast if list.empty?
 
     head = list.first.unwrap
 
-    return invoke_list(list, env) unless head.is_a? Mal::Symbol
+    return invoke_list(list, env) unless head.is_a? Crisp::Symbol
 
-    return Mal::Type.new case head.str
+    return Crisp::Type.new case head.str
       when "def!"
         eval_error "wrong number of argument for 'def!'" unless list.size == 3
         a1 = list[1].unwrap
-        eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol
+        eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Crisp::Symbol
         env.set(a1.str, eval(list[2], env))
       when "let*"
         eval_error "wrong number of argument for 'def!'" unless list.size == 3
@@ -167,11 +167,11 @@ def eval(ast, env)
         eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
         eval_error "size of binding list must be even" unless bindings.size.even?
 
-        new_env = Mal::Env.new env
+        new_env = Crisp::Env.new env
         bindings.each_slice(2) do |binding|
           key, value = binding
           name = key.unwrap
-          eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Mal::Symbol
+          eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Crisp::Symbol
           new_env.set(name.str, eval(value, new_env))
         end
 
@@ -179,16 +179,16 @@ def eval(ast, env)
         next # TCO
       when "do"
         if list.empty?
-          ast = Mal::Type.new nil
+          ast = Crisp::Type.new nil
           next
         end
 
-        eval_ast(list[1..-2].to_mal, env)
+        eval_ast(list[1..-2].to_crisp_value, env)
         ast = list.last
         next # TCO
       when "if"
         ast = unless eval(list[1], env).unwrap
-          list.size >= 4 ? list[3] : Mal::Type.new(nil)
+          list.size >= 4 ? list[3] : Crisp::Type.new(nil)
         else
           list[2]
         end
@@ -198,7 +198,7 @@ def eval(ast, env)
         unless params.is_a? Array
           eval_error "'fn*' parameters must be list or vector: #{params}"
         end
-        Mal::Closure.new(list[2], params, env, func_of(env, params, list[2]))
+        Crisp::Closure.new(list[2], params, env, func_of(env, params, list[2]))
       when "quote"
         list[1]
       when "quasiquote"
@@ -207,25 +207,25 @@ def eval(ast, env)
       when "defmacro!"
         eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3
         a1 = list[1].unwrap
-        eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol
+        eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Crisp::Symbol
         env.set(a1.str, eval(list[2], env).tap{|n| n.is_macro = true})
       when "macroexpand"
         macroexpand(list[1], env)
       when "try*"
         catch_list = list[2].unwrap
-        return eval(list[1], env) unless catch_list.is_a? Mal::List
+        return eval(list[1], env) unless catch_list.is_a? Crisp::List
 
         catch_head = catch_list.first.unwrap
-        return eval(list[1], env) unless catch_head.is_a? Mal::Symbol
+        return eval(list[1], env) unless catch_head.is_a? Crisp::Symbol
         return eval(list[1], env) unless catch_head.str == "catch*"
 
         begin
           eval(list[1], env)
-        rescue e : Mal::RuntimeException
-          new_env = Mal::Env.new(env, [catch_list[1]], [e.thrown])
+        rescue e : Crisp::RuntimeException
+          new_env = Crisp::Env.new(env, [catch_list[1]], [e.thrown])
           eval(catch_list[2], new_env)
         rescue e
-          new_env = Mal::Env.new(env, [catch_list[1]], [Mal::Type.new e.message])
+          new_env = Crisp::Env.new(env, [catch_list[1]], [Crisp::Type.new e.message])
           eval(catch_list[2], new_env)
         end
       else
@@ -242,22 +242,22 @@ def rep(str)
   print(eval(read(str), $repl_env))
 end
 
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-$repl_env.set("eval", Mal::Type.new -> (args: Array(Mal::Type)){ eval(args[0], $repl_env) })
+$repl_env = Crisp::Env.new nil
+Crisp::NS.each{|k,v| $repl_env.set(k, Crisp::Type.new(v))}
+$repl_env.set("eval", Crisp::Type.new -> (args: Array(Crisp::Type)){ eval(args[0], $repl_env) })
 rep "(def! not (fn* (a) (if a false true)))"
 rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
 rep "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"
 rep "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))"
 rep("(def! *host-language* \"crystal\")")
 
-$argv = Mal::List.new
-$repl_env.set("*ARGV*", Mal::Type.new $argv)
+$argv = Crisp::List.new
+$repl_env.set("*ARGV*", Crisp::Type.new $argv)
 
 unless ARGV.empty?
   if ARGV.size > 1
     ARGV[1..-1].each do |a|
-      $argv << Mal::Type.new(a)
+      $argv << Crisp::Type.new(a)
     end
   end
 
@@ -269,9 +269,7 @@ unless ARGV.empty?
   exit
 end
 
-rep("(println (str \"Mal [\" *host-language* \"]\"))")
-
-while line = my_readline("user> ")
+while line = my_readline("Crisp> ")
   begin
     puts rep(line)
   rescue e
diff --git a/src/env.cr b/src/env.cr
index 9f38d68..bed7e36 100644
--- a/src/env.cr
+++ b/src/env.cr
@@ -1,17 +1,17 @@
 require "./types"
 require "./error"
 
-module Mal
+module Crisp
 
   class Env
     property data
 
     def initialize(@outer)
-      @data = {} of String => Mal::Type
+      @data = {} of String => Crisp::Type
     end
 
-    def initialize(@outer, binds, exprs : Array(Mal::Type))
-      @data = {} of String => Mal::Type
+    def initialize(@outer, binds, exprs : Array(Crisp::Type))
+      @data = {} of String => Crisp::Type
 
       eval_error "binds must be list or vector" unless binds.is_a? Array
 
@@ -19,15 +19,15 @@ module Mal
       # Array#zip() can't be used because overload resolution failed
       (0...binds.size).each do |idx|
         sym = binds[idx].unwrap
-        eval_error "bind name must be symbol" unless sym.is_a? Mal::Symbol
+        eval_error "bind name must be symbol" unless sym.is_a? Crisp::Symbol
 
         if sym.str == "&"
           eval_error "missing variable parameter name" if binds.size == idx
           next_param = binds[idx+1].unwrap
-          eval_error "bind name must be symbol" unless next_param.is_a? Mal::Symbol
-          var_args = Mal::List.new
+          eval_error "bind name must be symbol" unless next_param.is_a? Crisp::Symbol
+          var_args = Crisp::List.new
           exprs[idx..-1].each{|e| var_args << e} if idx < exprs.size
-          @data[next_param.str] = Mal::Type.new var_args
+          @data[next_param.str] = Crisp::Type.new var_args
           break
         end
 
diff --git a/src/error.cr b/src/error.cr
index 6df309d..dde354c 100644
--- a/src/error.cr
+++ b/src/error.cr
@@ -1,4 +1,4 @@
-module Mal
+module Crisp
   class ParseException < Exception
   end
 
@@ -14,9 +14,9 @@ module Mal
 end
 
 def eval_error(msg)
-  raise Mal::EvalException.new msg
+  raise Crisp::EvalException.new msg
 end
 
 def parse_error(msg)
-  raise Mal::ParseException.new msg
+  raise Crisp::ParseException.new msg
 end
diff --git a/src/printer.cr b/src/printer.cr
index 7444cb2..ef88fe2 100644
--- a/src/printer.cr
+++ b/src/printer.cr
@@ -5,12 +5,12 @@ def pr_str(value, print_readably = true)
   when Nil          then "nil"
   when Bool         then value.to_s
   when Int32        then value.to_s
-  when Mal::List    then "(#{value.map{|v| pr_str(v, print_readably) as String}.join(" ")})"
-  when Mal::Vector  then "[#{value.map{|v| pr_str(v, print_readably) as String}.join(" ")}]"
-  when Mal::Symbol  then value.str.to_s
-  when Mal::Func    then "<function>"
-  when Mal::Closure then "<closure>"
-  when Mal::HashMap
+  when Crisp::List    then "(#{value.map{|v| pr_str(v, print_readably) as String}.join(" ")})"
+  when Crisp::Vector  then "[#{value.map{|v| pr_str(v, print_readably) as String}.join(" ")}]"
+  when Crisp::Symbol  then value.str.to_s
+  when Crisp::Func    then "<function>"
+  when Crisp::Closure then "<closure>"
+  when Crisp::HashMap
     # step1_read_print.cr requires specifying type
     "{#{value.map{|k, v| "#{pr_str(k, print_readably)} #{pr_str(v, print_readably)}" as String}.join(" ")}}"
   when String
@@ -22,13 +22,13 @@ def pr_str(value, print_readably = true)
     else
       print_readably ? value.inspect : value
     end
-  when Mal::Atom
+  when Crisp::Atom
     "(atom #{pr_str(value.val, print_readably)})"
   else
-    raise "invalid MalType: #{value.to_s}"
+    raise "invalid CrispType: #{value.to_s}"
   end
 end
 
-def pr_str(t : Mal::Type, print_readably = true)
+def pr_str(t : Crisp::Type, print_readably = true)
   pr_str(t.unwrap, print_readably) + (t.macro? ? " (macro)" : "")
 end
diff --git a/src/reader.cr b/src/reader.cr
index 74a5605..ea31bd0 100644
--- a/src/reader.cr
+++ b/src/reader.cr
@@ -46,18 +46,18 @@ class Reader
   end
 
   def read_list
-    Mal::Type.new read_sequence(Mal::List.new, '(', ')')
+    Crisp::Type.new read_sequence(Crisp::List.new, '(', ')')
   end
 
   def read_vector
-    Mal::Type.new read_sequence(Mal::Vector.new, '[', ']')
+    Crisp::Type.new read_sequence(Crisp::Vector.new, '[', ']')
   end
 
   def read_hashmap
-    types = read_sequence([] of Mal::Type, '{', '}')
+    types = read_sequence([] of Crisp::Type, '{', '}')
 
     parse_error "odd number of elements for hash-map: #{types.size}" if types.size.odd?
-    map = Mal::HashMap.new
+    map = Crisp::HashMap.new
 
     types.each_slice(2) do |kv|
       k, v = kv[0].unwrap, kv[1]
@@ -69,26 +69,26 @@ class Reader
       end
     end
 
-    Mal::Type.new map
+    Crisp::Type.new map
   end
 
   def read_atom
     token = self.next
     parse_error "expected Atom but got EOF" unless token
 
-    Mal::Type.new case
+    Crisp::Type.new case
     when token =~ /^-?\d+$/ then token.to_i
     when token == "true"    then true
     when token == "false"   then false
     when token == "nil"     then nil
     when token[0] == '"'    then token[1..-2].gsub(/\\"/, "\"")
     when token[0] == ':'    then "\u029e#{token[1..-1]}"
-    else                         Mal::Symbol.new token
+    else                         Crisp::Symbol.new token
     end
   end
 
   def list_of(symname)
-    Mal::List.new << gen_type(Mal::Symbol, symname) << read_form
+    Crisp::List.new << gen_type(Crisp::Symbol, symname) << read_form
   end
 
   def read_form
@@ -97,7 +97,7 @@ class Reader
     parse_error "unexpected EOF" unless token
     parse_error "unexpected comment" if token[0] == ';'
 
-    Mal::Type.new case token
+    Crisp::Type.new case token
     when "("  then read_list
     when ")"  then parse_error "unexpected ')'"
     when "["  then read_vector
@@ -130,7 +130,7 @@ def read_str(str)
     r.read_form
   ensure
     unless r.peek.nil?
-      raise Mal::ParseException.new "expected EOF, got #{r.peek.to_s}"
+      raise Crisp::ParseException.new "expected EOF, got #{r.peek.to_s}"
     end
   end
 end
diff --git a/src/step0_repl.cr b/src/step0_repl.cr
deleted file mode 100755
index e1fe58a..0000000
--- a/src/step0_repl.cr
+++ /dev/null
@@ -1,26 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def read(x)
-    x
-end
-
-def eval(x)
-    x
-end
-
-def print(x)
-    x
-end
-
-def rep(x)
-    read(eval(print(x)))
-end
-
-while line = my_readline("user> ")
-    puts rep(line)
-end
diff --git a/src/step1_read_print.cr b/src/step1_read_print.cr
deleted file mode 100755
index 1f3896d..0000000
--- a/src/step1_read_print.cr
+++ /dev/null
@@ -1,32 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def read(str)
-  read_str str
-end
-
-def eval(x)
-    x
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str)))
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step2_eval.cr b/src/step2_eval.cr
deleted file mode 100755
index a9bf00d..0000000
--- a/src/step2_eval.cr
+++ /dev/null
@@ -1,90 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def eval_error(msg)
-  raise Mal::EvalException.new msg
-end
-
-def num_func(func)
-  -> (args : Array(Mal::Type)) {
-    x, y = args[0].unwrap, args[1].unwrap
-    eval_error "invalid arguments" unless x.is_a?(Int32) && y.is_a?(Int32)
-    Mal::Type.new func.call(x, y)
-  }
-end
-
-$repl_env = {
-  "+" => num_func(->(x : Int32, y : Int32){ x + y }),
-  "-" => num_func(->(x : Int32, y : Int32){ x - y }),
-  "*" => num_func(->(x : Int32, y : Int32){ x * y }),
-  "/" => num_func(->(x : Int32, y : Int32){ x / y }),
-} of String => Mal::Func
-
-def eval_ast(a, env)
-  return a.map{|n| eval(n, env) as Mal::Type} if a.is_a? Mal::List
-  return a unless a
-
-  ast = a.unwrap
-  case ast
-  when Mal::Symbol
-    if env.has_key? ast.str
-      env[ast.str]
-    else
-      eval_error "'#{ast.str}' not found"
-    end
-  when Mal::List
-    ast.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    ast.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Mal::HashMap
-    ast.each{|k, v| ast[k] = eval(v, env)}
-  else
-    ast
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-def eval(t, env)
-  Mal::Type.new case ast = t.unwrap
-  when Mal::List
-    eval_error "empty list" if ast.empty?
-
-    f = eval_ast(ast.first, env)
-    ast.shift(1)
-    args = eval_ast(ast, env)
-
-    if f.is_a?(Mal::Func)
-      f.call(args)
-    else
-      eval_error "expected function symbol as the first symbol of list"
-    end
-  else
-    eval_ast(t, env)
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step3_env.cr b/src/step3_env.cr
deleted file mode 100755
index 9c7fc99..0000000
--- a/src/step3_env.cr
+++ /dev/null
@@ -1,115 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def eval_error(msg)
-  raise Mal::EvalException.new msg
-end
-
-def num_func(func)
-  -> (args : Array(Mal::Type)) {
-    x, y = args[0].unwrap, args[1].unwrap
-    eval_error "invalid arguments" unless x.is_a?(Int32) && y.is_a?(Int32)
-    Mal::Type.new func.call(x, y)
-  }
-end
-
-$repl_env = Mal::Env.new nil
-$repl_env.set("+", Mal::Type.new num_func(->(x : Int32, y : Int32){ x + y }))
-$repl_env.set("-", Mal::Type.new num_func(->(x : Int32, y : Int32){ x - y }))
-$repl_env.set("*", Mal::Type.new num_func(->(x : Int32, y : Int32){ x * y }))
-$repl_env.set("/", Mal::Type.new num_func(->(x : Int32, y : Int32){ x / y }))
-
-def eval_ast(a, env)
-  return a.map{|n| eval(n, env) } if a.is_a? Array
-
-  Mal::Type.new case ast = a.unwrap
-  when Mal::Symbol
-    if e = env.get(ast.str)
-      e
-    else
-      eval_error "'#{ast.str}' not found"
-    end
-  when Mal::List
-    ast.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    ast.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Mal::HashMap
-    new_map = Mal::HashMap.new
-    ast.each{|k, v| new_map[k] = eval(v, env)}
-    new_map
-  else
-    ast
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-def eval(t, env)
-  ast = t.unwrap
-
-  return eval_ast(t, env) unless ast.is_a?(Mal::List)
-
-  eval_error "empty list" if ast.empty?
-
-  sym = ast.first.unwrap
-  eval_error "first element of list must be a symbol" unless sym.is_a?(Mal::Symbol)
-
-  Mal::Type.new case sym.str
-  when "def!"
-    eval_error "wrong number of argument for 'def!'" unless ast.size == 3
-    a1 = ast[1].unwrap
-    eval_error "1st argument of 'def!' must be symbol" unless a1.is_a?(Mal::Symbol)
-    env.set(a1.str, eval(ast[2], env) as Mal::Type)
-  when "let*"
-    eval_error "wrong number of argument for 'def!'" unless ast.size == 3
-
-    bindings = ast[1].unwrap
-    eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a?(Array)
-    eval_error "size of binding list must be even" unless bindings.size.even?
-
-    new_env = Mal::Env.new env
-    bindings.each_slice(2) do |binding|
-      name, value = binding[0].unwrap, binding[1]
-      eval_error "name of binding must be specified as symbol" unless name.is_a?(Mal::Symbol)
-      new_env.set(name.str, eval(value, new_env))
-    end
-
-    eval(ast[2], new_env)
-  else
-    f = eval_ast(ast.first, env)
-    ast.shift(1)
-    args = eval_ast(ast, env)
-
-    if f.is_a?(Mal::Type) && (f2 = f.unwrap).is_a?(Mal::Func)
-      f2.call(args as Array(Mal::Type))
-    else
-      eval_error "expected function symbol as the first symbol of list"
-    end
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step4_if_fn_do.cr b/src/step4_if_fn_do.cr
deleted file mode 100755
index 3dc861c..0000000
--- a/src/step4_if_fn_do.cr
+++ /dev/null
@@ -1,130 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-require "./core"
-require "./error"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
-    eval(body, new_env)
-  } as Mal::Func
-end
-
-def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
-
-  val = ast.unwrap
-
-  Mal::Type.new case val
-  when Mal::Symbol
-    if e = env.get(val.str)
-      e
-    else
-      eval_error "'#{val.str}' not found"
-    end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Mal::HashMap
-    val.each{|k, v| val[k] = eval(v, env)}
-    val
-  else
-    val
-  end
-end
-
-def eval_invocation(list, env)
-  f = eval(list.first, env).unwrap
-  eval_error "expected function symbol as the first symbol of list" unless f.is_a? Mal::Func
-  f.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
-end
-
-def read(str)
-  read_str str
-end
-
-def eval(ast, env)
-  list = ast.unwrap
-
-  return eval_ast(ast, env)          unless list.is_a? Mal::List
-  return gen_type Mal::List if list.empty?
-
-  head = list.first.unwrap
-
-  Mal::Type.new case head
-  when Mal::Symbol
-    case head.str
-    when "def!"
-      eval_error "wrong number of argument for 'def!'" unless list.size == 3
-      a1 = list[1].unwrap
-      eval_error "1st argument of 'def!' must be symbol" unless a1.is_a? Mal::Symbol
-      env.set(a1.str, eval(list[2], env))
-    when "let*"
-      eval_error "wrong number of argument for 'def!'" unless list.size == 3
-
-      bindings = list[1].unwrap
-      eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
-      eval_error "size of binding list must be even" unless bindings.size.even?
-
-      new_env = Mal::Env.new env
-      bindings.each_slice(2) do |binding|
-        key, value = binding
-        name = key.unwrap
-        eval_error "name of binding must be specified as symbol" unless name.is_a? Mal::Symbol
-        new_env.set(name.str, eval(value, new_env))
-      end
-
-      eval(list[2], new_env)
-    when "do"
-      list.shift 1
-      eval_ast(list, env).last
-    when "if"
-      cond = eval(list[1], env).unwrap
-      case cond
-      when Nil
-        list.size >= 4 ? eval(list[3], env) : nil
-      when false
-        list.size >= 4 ?  eval(list[3], env) : nil
-      else
-        eval(list[2], env)
-      end
-    when "fn*"
-      # Note:
-      # If writing lambda expression here directly, compiler will fail to infer type of 'list'. (Error 'Nil for empty?')
-      func_of(env, list[1].unwrap, list[2])
-    else
-      eval_invocation(list, env)
-    end
-  else
-    eval_invocation(list, env)
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-rep "(def! not (fn* (a) (if a false true)))"
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step5_tco.cr b/src/step5_tco.cr
deleted file mode 100755
index 450e399..0000000
--- a/src/step5_tco.cr
+++ /dev/null
@@ -1,164 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-require "./core"
-require "./error"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
-    eval(body, new_env)
-  } as Mal::Func
-end
-
-def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
-
-  val = ast.unwrap
-
-  Mal::Type.new case val
-  when Mal::Symbol
-    if e = env.get(val.str)
-      e
-    else
-      eval_error "'#{val.str}' not found"
-    end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Array(Mal::Type)
-    val.map{|n| eval(n, env)}
-  when Mal::HashMap
-    val.each{|k, v| val[k] = eval(v, env)}
-    val
-  else
-    val
-  end
-end
-
-def eval_invocation(list, env)
-  f = eval(list.first, env).unwrap
-  case f
-  when Mal::Closure
-    f.fn.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
-  when Mal::Func
-    f.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
-  else
-    eval_error "expected function as the first argument"
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-macro invoke_list(l)
-  f = eval({{l}}.first, env).unwrap
-  args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
-  case f
-  when Mal::Closure
-    ast = f.ast
-    env = Mal::Env.new(f.env, f.params, args)
-    next # TCO
-  when Mal::Func
-    return f.call args
-  else
-    eval_error "expected function as the first argument"
-  end
-end
-
-def eval(ast, env)
-  # 'next' in 'do...end' has a bug in crystal 0.7.1
-  # https://github.com/manastech/crystal/issues/659
-  while true
-    list = ast.unwrap
-
-    return eval_ast(ast, env) unless list.is_a? Mal::List
-    return gen_type Mal::List if list.empty?
-
-    head = list.first.unwrap
-
-    unless head.is_a? Mal::Symbol
-      invoke_list list
-    end
-
-    return Mal::Type.new case head.str
-      when "def!"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'def!' must be symbol" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env))
-      when "let*"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-
-        bindings = list[1].unwrap
-        eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
-        eval_error "size of binding list must be even" unless bindings.size.even?
-
-        new_env = Mal::Env.new env
-        bindings.each_slice(2) do |binding|
-          key, value = binding
-          name = key.unwrap
-          eval_error "name of binding must be specified as symbol" unless name.is_a? Mal::Symbol
-          new_env.set(name.str, eval(value, new_env))
-        end
-
-        ast, env = list[2], new_env
-        next # TCO
-      when "do"
-        if list.empty?
-          ast = Mal::Type.new nil
-          next
-        end
-
-        eval_ast(list[1..-2].each_with_object(Mal::List.new){|i,l| l << i}, env)
-        ast = list.last
-        next # TCO
-      when "if"
-        ast = unless eval(list[1], env).unwrap
-          list.size >= 4 ? list[3] : Mal::Type.new(nil)
-        else
-          list[2]
-        end
-        next # TCO
-      when "fn*"
-        # Note:
-        # If writing lambda expression here directly, compiler will fail to infer type of 'list'. (Error 'Nil for empty?')
-        params = list[1].unwrap
-        unless params.is_a?(Mal::List) || params.is_a?(Mal::Vector)
-          eval_error "'fn*' parameters must be list"
-        end
-        Mal::Closure.new(list[2], params, env, func_of(env, list[1].unwrap, list[2]))
-      else
-        invoke_list list
-      end
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-rep "(def! not (fn* (a) (if a false true)))"
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step6_file.cr b/src/step6_file.cr
deleted file mode 100755
index 1ffe493..0000000
--- a/src/step6_file.cr
+++ /dev/null
@@ -1,177 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-require "./core"
-require "./error"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
-    eval(body, new_env)
-  } as Mal::Func
-end
-
-def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
-
-  val = ast.unwrap
-
-  Mal::Type.new case val
-  when Mal::Symbol
-    if e = env.get(val.str)
-      e
-    else
-      eval_error "'#{val.str}' not found"
-    end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Array(Mal::Type)
-    val.map{|n| eval(n, env)}
-  when Mal::HashMap
-    val.each{|k, v| val[k] = eval(v, env)}
-    val
-  else
-    val
-  end
-end
-
-def eval_invocation(list, env)
-  f = eval(list.first, env).unwrap
-  case f
-  when Mal::Closure
-    f.fn.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
-  when Mal::Func
-    f.call eval_ast(list[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, env)
-  else
-    eval_error "expected function as the first argument"
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-macro invoke_list(l, env)
-  f = eval({{l}}.first, {{env}}).unwrap
-  args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, {{env}})
-  case f
-  when Mal::Closure
-    ast = f.ast
-    {{env}} = Mal::Env.new(f.env, f.params, args)
-    next # TCO
-  when Mal::Func
-    return f.call args
-  else
-    eval_error "expected function as the first argument"
-  end
-end
-
-def eval(ast, env)
-  # 'next' in 'do...end' has a bug in crystal 0.7.1
-  # https://github.com/manastech/crystal/issues/659
-  while true
-    list = ast.unwrap
-
-    return eval_ast(ast, env) unless list.is_a? Mal::List
-    return gen_type Mal::List if list.empty?
-
-    head = list.first.unwrap
-
-    unless head.is_a? Mal::Symbol
-      invoke_list(list, env)
-    end
-
-    return Mal::Type.new case head.str
-      when "def!"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'def!' must be symbol" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env))
-      when "let*"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-
-        bindings = list[1].unwrap
-        eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
-        eval_error "size of binding list must be even" unless bindings.size.even?
-
-        new_env = Mal::Env.new env
-        bindings.each_slice(2) do |binding|
-          key, value = binding
-          name = key.unwrap
-          eval_error "name of binding must be specified as symbol" unless name.is_a? Mal::Symbol
-          new_env.set(name.str, eval(value, new_env))
-        end
-
-        ast, env = list[2], new_env
-        next # TCO
-      when "do"
-        if list.empty?
-          ast = Mal::Type.new nil
-          next
-        end
-
-        eval_ast(list[1..-2].each_with_object(Mal::List.new){|i,l| l << i}, env)
-        ast = list.last
-        next # TCO
-      when "if"
-        ast = unless eval(list[1], env).unwrap
-          list.size >= 4 ? list[3] : Mal::Type.new(nil)
-        else
-          list[2]
-        end
-        next # TCO
-      when "fn*"
-        params = list[1].unwrap
-        unless params.is_a?(Mal::List) || params.is_a?(Mal::Vector)
-          eval_error "'fn*' parameters must be list"
-        end
-        Mal::Closure.new(list[2], params, env, func_of(env, params, list[2]))
-      else
-        invoke_list(list, env)
-      end
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-$repl_env.set("eval", Mal::Type.new -> (args: Array(Mal::Type)){ eval(args[0], $repl_env) })
-rep "(def! not (fn* (a) (if a false true)))"
-rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
-$argv = Mal::List.new
-$repl_env.set("*ARGV*", Mal::Type.new $argv)
-
-unless ARGV.empty?
-  if ARGV.size > 1
-    ARGV[1..-1].each do |a|
-      $argv << Mal::Type.new(a)
-    end
-  end
-
-  rep "(load-file \"#{ARGV[0]}\")"
-  exit
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step7_quote.cr b/src/step7_quote.cr
deleted file mode 100755
index 2c43818..0000000
--- a/src/step7_quote.cr
+++ /dev/null
@@ -1,207 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-require "./core"
-require "./error"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
-    eval(body, new_env)
-  } as Mal::Func
-end
-
-def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
-
-  val = ast.unwrap
-
-  Mal::Type.new case val
-  when Mal::Symbol
-    if e = env.get(val.str)
-      e
-    else
-      eval_error "'#{val.str}' not found"
-    end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Array(Mal::Type)
-    val.map{|n| eval(n, env)}
-  when Mal::HashMap
-    val.each{|k, v| val[k] = eval(v, env)}
-    val
-  else
-    val
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-macro is_pair(list)
-  {{list}}.is_a?(Array) && !{{list}}.empty?
-end
-
-def quasiquote(ast)
-  list = ast.unwrap
-
-  unless is_pair(list)
-    return Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "quote") << ast
-    )
-  end
-
-  head = list.first.unwrap
-
-  case
-  # ("unquote" ...)
-  when head.is_a?(Mal::Symbol) && head.str == "unquote"
-    list[1]
-  # (("splice-unquote" ...) ...)
-  when is_pair(head) && (arg0 = head.first.unwrap).is_a?(Mal::Symbol) && arg0.str == "splice-unquote"
-    tail = Mal::Type.new list[1..-1].each_with_object(Mal::List.new){|e,l| l << e}
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "concat") << head[1] << quasiquote(tail)
-    )
-  else
-    tail = Mal::Type.new list[1..-1].each_with_object(Mal::List.new){|e,l| l << e}
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
-    )
-  end
-end
-
-macro invoke_list(l, env)
-  f = eval({{l}}.first, {{env}}).unwrap
-  args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, {{env}})
-  case f
-  when Mal::Closure
-    ast = f.ast
-    {{env}} = Mal::Env.new(f.env, f.params, args)
-    next # TCO
-  when Mal::Func
-    return f.call args
-  else
-    eval_error "expected function as the first argument"
-  end
-end
-
-def eval(ast, env)
-  # 'next' in 'do...end' has a bug in crystal 0.7.1
-  # https://github.com/manastech/crystal/issues/659
-  while true
-    list = ast.unwrap
-
-    return eval_ast(ast, env) unless list.is_a? Mal::List
-    return gen_type Mal::List if list.empty?
-
-    head = list.first.unwrap
-
-    unless head.is_a? Mal::Symbol
-      return invoke_list(list, env)
-    end
-
-    return Mal::Type.new case head.str
-      when "def!"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'def!' must be symbol" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env))
-      when "let*"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-
-        bindings = list[1].unwrap
-        eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
-        eval_error "size of binding list must be even" unless bindings.size.even?
-
-        new_env = Mal::Env.new env
-        bindings.each_slice(2) do |binding|
-          key, value = binding
-          name = key.unwrap
-          eval_error "name of binding must be specified as symbol" unless name.is_a? Mal::Symbol
-          new_env.set(name.str, eval(value, new_env))
-        end
-
-        ast, env = list[2], new_env
-        next # TCO
-      when "do"
-        if list.empty?
-          ast = Mal::Type.new nil
-          next
-        end
-
-        eval_ast(list[1..-2].each_with_object(Mal::List.new){|i,l| l << i}, env)
-        ast = list.last
-        next # TCO
-      when "if"
-        ast = unless eval(list[1], env).unwrap
-          list.size >= 4 ? list[3] : Mal::Type.new(nil)
-        else
-          list[2]
-        end
-        next # TCO
-      when "fn*"
-        params = list[1].unwrap
-        unless params.is_a?(Mal::List) || params.is_a?(Mal::Vector)
-          eval_error "'fn*' parameters must be list"
-        end
-        Mal::Closure.new(list[2], params, env, func_of(env, params, list[2]))
-      when "quote"
-        list[1]
-      when "quasiquote"
-        ast = quasiquote list[1]
-        next # TCO
-      else
-        invoke_list(list, env)
-      end
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-$repl_env.set("eval", Mal::Type.new -> (args: Array(Mal::Type)){ eval(args[0], $repl_env) })
-rep "(def! not (fn* (a) (if a false true)))"
-rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
-$argv = Mal::List.new
-$repl_env.set("*ARGV*", Mal::Type.new $argv)
-
-unless ARGV.empty?
-  if ARGV.size > 1
-    ARGV[1..-1].each do |a|
-      $argv << Mal::Type.new(a)
-    end
-  end
-
-  begin
-    rep "(load-file \"#{ARGV[0]}\")"
-  rescue e
-    STDERR.puts e
-  end
-  exit
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step8_macros.cr b/src/step8_macros.cr
deleted file mode 100755
index 73f1470..0000000
--- a/src/step8_macros.cr
+++ /dev/null
@@ -1,253 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-require "./core"
-require "./error"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
-    eval(body, new_env)
-  } as Mal::Func
-end
-
-def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
-
-  val = ast.unwrap
-
-  Mal::Type.new case val
-  when Mal::Symbol
-    if e = env.get(val.str)
-      e
-    else
-      eval_error "'#{val.str}' not found"
-    end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Array(Mal::Type)
-    val.map{|n| eval(n, env)}
-  when Mal::HashMap
-    val.each{|k, v| val[k] = eval(v, env)}
-    val
-  else
-    val
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-macro pair?(list)
-  {{list}}.is_a?(Array) && !{{list}}.empty?
-end
-
-def quasiquote(ast)
-  list = ast.unwrap
-
-  unless pair?(list)
-    return Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "quote") << ast
-    )
-  end
-
-  head = list.first.unwrap
-
-  case
-  # ("unquote" ...)
-  when head.is_a?(Mal::Symbol) && head.str == "unquote"
-    list[1]
-  # (("splice-unquote" ...) ...)
-  when pair?(head) && (arg0 = head.first.unwrap).is_a?(Mal::Symbol) && arg0.str == "splice-unquote"
-    tail = Mal::Type.new list[1..-1].each_with_object(Mal::List.new){|e,l| l << e}
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "concat") << head[1] << quasiquote(tail)
-    )
-  else
-    tail = Mal::Type.new list[1..-1].each_with_object(Mal::List.new){|e,l| l << e}
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
-    )
-  end
-end
-
-def macro_call?(ast, env)
-  list = ast.unwrap
-  return false unless list.is_a? Mal::List
-
-  sym = list.first.unwrap
-  return false unless sym.is_a? Mal::Symbol
-
-  func = env.find(sym.str).try(&.data[sym.str])
-  return false unless func && func.macro?
-
-  true
-end
-
-def macroexpand(ast, env)
-  while macro_call?(ast, env)
-
-    # Already checked in macro_call?
-    list = ast.unwrap as Mal::List
-    func_sym = list[0].unwrap as Mal::Symbol
-    func = env.get(func_sym.str).unwrap
-
-    case func
-    when Mal::Func
-      ast = func.call(list[1..-1])
-    when Mal::Closure
-      ast = func.fn.call(list[1..-1])
-    else
-      eval_error "macro '#{func_sym.str}' must be function: #{ast}"
-    end
-  end
-
-  ast
-end
-
-macro invoke_list(l, env)
-  f = eval({{l}}.first, {{env}}).unwrap
-  args = eval_ast({{l}}[1..-1].each_with_object(Mal::List.new){|i, l| l << i}, {{env}})
-  case f
-  when Mal::Closure
-    ast = f.ast
-    {{env}} = Mal::Env.new(f.env, f.params, args)
-    next # TCO
-  when Mal::Func
-    return f.call args
-  else
-    eval_error "expected function as the first argument: #{f}"
-  end
-end
-
-def eval(ast, env)
-  # 'next' in 'do...end' has a bug in crystal 0.7.1
-  # https://github.com/manastech/crystal/issues/659
-  while true
-    return eval_ast(ast, env) unless ast.unwrap.is_a? Mal::List
-
-    ast = macroexpand(ast, env)
-
-    list = ast.unwrap
-
-    return ast unless list.is_a? Mal::List
-    return ast if list.empty?
-
-    head = list.first.unwrap
-
-    return invoke_list(list, env) unless head.is_a? Mal::Symbol
-
-    return Mal::Type.new case head.str
-      when "def!"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env))
-      when "let*"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-
-        bindings = list[1].unwrap
-        eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
-        eval_error "size of binding list must be even" unless bindings.size.even?
-
-        new_env = Mal::Env.new env
-        bindings.each_slice(2) do |binding|
-          key, value = binding
-          name = key.unwrap
-          eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Mal::Symbol
-          new_env.set(name.str, eval(value, new_env))
-        end
-
-        ast, env = list[2], new_env
-        next # TCO
-      when "do"
-        if list.empty?
-          ast = Mal::Type.new nil
-          next
-        end
-
-        eval_ast(list[1..-2].each_with_object(Mal::List.new){|i,l| l << i}, env)
-        ast = list.last
-        next # TCO
-      when "if"
-        ast = unless eval(list[1], env).unwrap
-          list.size >= 4 ? list[3] : Mal::Type.new(nil)
-        else
-          list[2]
-        end
-        next # TCO
-      when "fn*"
-        params = list[1].unwrap
-        unless params.is_a? Array
-          eval_error "'fn*' parameters must be list or vector: #{params}"
-        end
-        Mal::Closure.new(list[2], params, env, func_of(env, params, list[2]))
-      when "quote"
-        list[1]
-      when "quasiquote"
-        ast = quasiquote list[1]
-        next # TCO
-      when "defmacro!"
-        eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env).tap{|n| n.is_macro = true})
-      when "macroexpand"
-        macroexpand(list[1], env)
-      else
-        invoke_list(list, env)
-      end
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-$repl_env.set("eval", Mal::Type.new -> (args: Array(Mal::Type)){ eval(args[0], $repl_env) })
-rep "(def! not (fn* (a) (if a false true)))"
-rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
-rep "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"
-rep "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))"
-
-$argv = Mal::List.new
-$repl_env.set("*ARGV*", Mal::Type.new $argv)
-
-unless ARGV.empty?
-  if ARGV.size > 1
-    ARGV[1..-1].each do |a|
-      $argv << Mal::Type.new(a)
-    end
-  end
-
-  begin
-    rep "(load-file \"#{ARGV[0]}\")"
-  rescue e
-    STDERR.puts e
-  end
-  exit
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/step9_try.cr b/src/step9_try.cr
deleted file mode 100755
index 3d2c964..0000000
--- a/src/step9_try.cr
+++ /dev/null
@@ -1,270 +0,0 @@
-#! /usr/bin/env crystal run
-
-require "./readline"
-require "./reader"
-require "./printer"
-require "./types"
-require "./env"
-require "./core"
-require "./error"
-
-# Note:
-# Employed downcase names because Crystal prohibits uppercase names for methods
-
-def func_of(env, binds, body)
-  -> (args : Array(Mal::Type)) {
-    new_env = Mal::Env.new(env, binds, args)
-    eval(body, new_env)
-  } as Mal::Func
-end
-
-def eval_ast(ast, env)
-  return ast.map{|n| eval(n, env) as Mal::Type} if ast.is_a? Mal::List
-
-  val = ast.unwrap
-
-  Mal::Type.new case val
-  when Mal::Symbol
-    if e = env.get(val.str)
-      e
-    else
-      eval_error "'#{val.str}' not found"
-    end
-  when Mal::List
-    val.each_with_object(Mal::List.new){|n, l| l << eval(n, env)}
-  when Mal::Vector
-    val.each_with_object(Mal::Vector.new){|n, l| l << eval(n, env)}
-  when Array(Mal::Type)
-    val.map{|n| eval(n, env)}
-  when Mal::HashMap
-    val.each{|k, v| val[k] = eval(v, env)}
-    val
-  else
-    val
-  end
-end
-
-def read(str)
-  read_str str
-end
-
-macro pair?(list)
-  {{list}}.is_a?(Array) && !{{list}}.empty?
-end
-
-def quasiquote(ast)
-  list = ast.unwrap
-
-  unless pair?(list)
-    return Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "quote") << ast
-    )
-  end
-
-  head = list.first.unwrap
-
-  case
-  # ("unquote" ...)
-  when head.is_a?(Mal::Symbol) && head.str == "unquote"
-    list[1]
-  # (("splice-unquote" ...) ...)
-  when pair?(head) && (arg0 = head.first.unwrap).is_a?(Mal::Symbol) && arg0.str == "splice-unquote"
-    tail = Mal::Type.new list[1..-1].to_mal
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "concat") << head[1] << quasiquote(tail)
-    )
-  else
-    tail = Mal::Type.new list[1..-1].to_mal
-    Mal::Type.new(
-      Mal::List.new << gen_type(Mal::Symbol, "cons") << quasiquote(list.first) << quasiquote(tail)
-    )
-  end
-end
-
-def macro_call?(ast, env)
-  list = ast.unwrap
-  return false unless list.is_a? Mal::List
-
-  sym = list.first.unwrap
-  return false unless sym.is_a? Mal::Symbol
-
-  func = env.find(sym.str).try(&.data[sym.str])
-  return false unless func && func.macro?
-
-  true
-end
-
-def macroexpand(ast, env)
-  while macro_call?(ast, env)
-
-    # Already checked in macro_call?
-    list = ast.unwrap as Mal::List
-    func_sym = list[0].unwrap as Mal::Symbol
-    func = env.get(func_sym.str).unwrap
-
-    case func
-    when Mal::Func
-      ast = func.call(list[1..-1])
-    when Mal::Closure
-      ast = func.fn.call(list[1..-1])
-    else
-      eval_error "macro '#{func_sym.str}' must be function: #{ast}"
-    end
-  end
-
-  ast
-end
-
-macro invoke_list(l, env)
-  f = eval({{l}}.first, {{env}}).unwrap
-  args = eval_ast({{l}}[1..-1].to_mal, {{env}})
-  case f
-  when Mal::Closure
-    ast = f.ast
-    {{env}} = Mal::Env.new(f.env, f.params, args)
-    next # TCO
-  when Mal::Func
-    return f.call args
-  else
-    eval_error "expected function as the first argument: #{f}"
-  end
-end
-
-def eval(ast, env)
-  # 'next' in 'do...end' has a bug in crystal 0.7.1
-  # https://github.com/manastech/crystal/issues/659
-  while true
-    return eval_ast(ast, env) unless ast.unwrap.is_a? Mal::List
-
-    ast = macroexpand(ast, env)
-
-    list = ast.unwrap
-
-    return ast unless list.is_a? Mal::List
-    return ast if list.empty?
-
-    head = list.first.unwrap
-
-    return invoke_list(list, env) unless head.is_a? Mal::Symbol
-
-    return Mal::Type.new case head.str
-      when "def!"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'def!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env))
-      when "let*"
-        eval_error "wrong number of argument for 'def!'" unless list.size == 3
-
-        bindings = list[1].unwrap
-        eval_error "1st argument of 'let*' must be list or vector" unless bindings.is_a? Array
-        eval_error "size of binding list must be even" unless bindings.size.even?
-
-        new_env = Mal::Env.new env
-        bindings.each_slice(2) do |binding|
-          key, value = binding
-          name = key.unwrap
-          eval_error "name of binding must be specified as symbol #{name}" unless name.is_a? Mal::Symbol
-          new_env.set(name.str, eval(value, new_env))
-        end
-
-        ast, env = list[2], new_env
-        next # TCO
-      when "do"
-        if list.empty?
-          ast = Mal::Type.new nil
-          next
-        end
-
-        eval_ast(list[1..-2].to_mal, env)
-        ast = list.last
-        next # TCO
-      when "if"
-        ast = unless eval(list[1], env).unwrap
-          list.size >= 4 ? list[3] : Mal::Type.new(nil)
-        else
-          list[2]
-        end
-        next # TCO
-      when "fn*"
-        params = list[1].unwrap
-        unless params.is_a? Array
-          eval_error "'fn*' parameters must be list or vector: #{params}"
-        end
-        Mal::Closure.new(list[2], params, env, func_of(env, params, list[2]))
-      when "quote"
-        list[1]
-      when "quasiquote"
-        ast = quasiquote list[1]
-        next # TCO
-      when "defmacro!"
-        eval_error "wrong number of argument for 'defmacro!'" unless list.size == 3
-        a1 = list[1].unwrap
-        eval_error "1st argument of 'defmacro!' must be symbol: #{a1}" unless a1.is_a? Mal::Symbol
-        env.set(a1.str, eval(list[2], env).tap{|n| n.is_macro = true})
-      when "macroexpand"
-        macroexpand(list[1], env)
-      when "try*"
-        catch_list = list[2].unwrap
-        return eval(list[1], env) unless catch_list.is_a? Mal::List
-
-        catch_head = catch_list.first.unwrap
-        return eval(list[1], env) unless catch_head.is_a? Mal::Symbol
-        return eval(list[1], env) unless catch_head.str == "catch*"
-
-        begin
-          eval(list[1], env)
-        rescue e : Mal::RuntimeException
-          new_env = Mal::Env.new(env, [catch_list[1]], [e.thrown])
-          eval(catch_list[2], new_env)
-        rescue e
-          new_env = Mal::Env.new(env, [catch_list[1]], [Mal::Type.new e.message])
-          eval(catch_list[2], new_env)
-        end
-      else
-        invoke_list(list, env)
-      end
-  end
-end
-
-def print(result)
-  pr_str(result, true)
-end
-
-def rep(str)
-  print(eval(read(str), $repl_env))
-end
-
-$repl_env = Mal::Env.new nil
-Mal::NS.each{|k,v| $repl_env.set(k, Mal::Type.new(v))}
-$repl_env.set("eval", Mal::Type.new -> (args: Array(Mal::Type)){ eval(args[0], $repl_env) })
-rep "(def! not (fn* (a) (if a false true)))"
-rep "(def! load-file (fn* (f) (eval (read-string (str \"(do \" (slurp f) \")\")))))"
-rep "(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list 'if (first xs) (if (> (count xs) 1) (nth xs 1) (throw \"odd number of forms to cond\")) (cons 'cond (rest (rest xs)))))))"
-rep "(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))"
-
-$argv = Mal::List.new
-$repl_env.set("*ARGV*", Mal::Type.new $argv)
-
-unless ARGV.empty?
-  if ARGV.size > 1
-    ARGV[1..-1].each do |a|
-      $argv << Mal::Type.new(a)
-    end
-  end
-
-  begin
-    rep "(load-file \"#{ARGV[0]}\")"
-  rescue e
-    STDERR.puts e
-  end
-  exit
-end
-
-while line = my_readline("user> ")
-  begin
-    puts rep(line)
-  rescue e
-    STDERR.puts e
-  end
-end
diff --git a/src/types.cr b/src/types.cr
index af61cb7..b8009a5 100644
--- a/src/types.cr
+++ b/src/types.cr
@@ -1,6 +1,6 @@
 require "./printer"
 
-module Mal
+module Crisp
   class Symbol
     property :str
     def initialize(@str)
@@ -81,7 +81,7 @@ module Mal
 
     macro rel_op(*ops)
       {% for op in ops %}
-        def {{op.id}}(other : Mal::Type)
+        def {{op.id}}(other : Crisp::Type)
           l, r = @val, other.unwrap
             {% for t in [Int32, String] %}
               if l.is_a?({{t}}) && r.is_a?({{t}})
@@ -103,11 +103,11 @@ module Mal
 end
 
 macro gen_type(t, *args)
-  Mal::Type.new {{t.id}}.new({{*args}})
+  Crisp::Type.new {{t.id}}.new({{*args}})
 end
 
 class Array
-  def to_mal(t = Mal::List)
+  def to_crisp_value(t = Crisp::List)
     each_with_object(t.new){|e, l| l << e}
   end
 end