From 09fb509eb44a93a0e18f41a0c676950f35230774 Mon Sep 17 00:00:00 2001
From: rhysd <lin90162@yahoo.co.jp>
Date: Fri, 29 May 2015 00:32:16 +0900
Subject: [PATCH] crystal: refactor by adding Array to Mal type conversion

---
 crystal/core.cr  | 16 +++++++---------
 crystal/types.cr |  7 +++++++
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/crystal/core.cr b/crystal/core.cr
index 67ef9f71..15ec78d6 100644
--- a/crystal/core.cr
+++ b/crystal/core.cr
@@ -14,7 +14,7 @@ macro calc_op(op)
 end
 
 def self.list(args)
-  args.each_with_object(Mal::List.new){|a,l| l << a}
+  args.to_mal
 end
 
 def self.list?(args)
@@ -73,11 +73,9 @@ def self.slurp(args)
 end
 
 def self.cons(args)
-  arg1 = args[1].unwrap
-  eval_error "2nd arg of cons must be list" unless arg1.is_a? Array
-  arg1.each_with_object(Mal::List.new << args[0]) do |elem, list|
-    list << elem
-  end
+  head, tail = args[0] as Mal::Type, args[1].unwrap
+  eval_error "2nd arg of cons must be list" unless tail.is_a? Array
+  ([head] + tail).to_mal
 end
 
 def self.concat(args)
@@ -109,7 +107,7 @@ def self.rest(args)
   return Mal::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].each_with_object(Mal::List.new){|e,l| l << e}
+  a0[1..-1].to_mal
 end
 
 def self.apply(args)
@@ -183,7 +181,7 @@ def self.keyword?(args)
 end
 
 def self.vector(args)
-  args.each_with_object(Mal::Vector.new){|e,v| v << e}
+  args.to_mal(Mal::Vector)
 end
 
 def self.vector?(args)
@@ -263,7 +261,7 @@ 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.each_with_object(Mal::List.new){|e,l| l << e}
+  head.values.to_mal
 end
 
 def self.sequential?(args)
diff --git a/crystal/types.cr b/crystal/types.cr
index 6f68ed0e..56203307 100644
--- a/crystal/types.cr
+++ b/crystal/types.cr
@@ -83,3 +83,10 @@ end
 macro gen_type(t, *args)
   Mal::Type.new {{t.id}}.new({{*args}})
 end
+
+class Array
+  def to_mal(t = Mal::List)
+    each_with_object(t.new){|e, l| l << e}
+  end
+end
+