From b2a84ddc6905db7e09499e2833b29dd9352ed703 Mon Sep 17 00:00:00 2001
From: James Moriarty <james.moriarty@rea-group.com>
Date: Sun, 25 Sep 2016 13:50:14 +1000
Subject: [PATCH] feature: strings.

---
 Gemfile           | 1 +
 lib/lisp.rb       | 8 +++++---
 test/test_lisp.rb | 5 +++--
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/Gemfile b/Gemfile
index cca4fab..7c31bcd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,7 @@
 source "https://rubygems.org"
 
 group :test do
+  gem "pry"
   gem "simplecov"
   gem "codeclimate-test-reporter", require: nil
 end
diff --git a/lib/lisp.rb b/lib/lisp.rb
index e0b3b4a..3356111 100644
--- a/lib/lisp.rb
+++ b/lib/lisp.rb
@@ -31,10 +31,12 @@ def self.parse tokens, tree = []
 
   def self.atom token
     case token
-    when /\d/
-      token.to_f % 1 > 0 ? token.to_f : token.to_i
+    when /^[0-9]+$/
+      token.to_i
+    when /[0-9]+\.?[0-9]+?$/
+      token.to_f
     else
-      token.to_sym
+      token[0] == token[-1] && token[0] == ?' ? token.slice(1..-2) : token.to_sym
     end
   end
 
diff --git a/test/test_lisp.rb b/test/test_lisp.rb
index 2c07862..e1311b7 100755
--- a/test/test_lisp.rb
+++ b/test/test_lisp.rb
@@ -22,8 +22,9 @@ def test_parse
   # representation
 
   def test_representation
-    assert_equal [:*, 2, [:+, 1, 0]],                              Lisp.parse(Lisp.tokenize("(* 2 (+ 1 0) )"))
+    assert_equal [:*, 2, [:+, 1.5, 0]],                            Lisp.parse(Lisp.tokenize("(* 2 (+ 1.5 0) )"))
     assert_equal [:lambda, [:r], [:*, 3.141592653, [:*, :r, :r]]], Lisp.parse(Lisp.tokenize("(lambda (r) (* 3.141592653 (* r r)))"))
+    assert_equal [:+, "hello", "world"],                           Lisp.parse(Lisp.tokenize("(+ 'hello' 'world')"))
   end
 
   # execution
@@ -112,7 +113,7 @@ def test_repl
       Process.kill("INT", pid)
       thread.join
     end
-    
+
     assert_output("ctrl-c to exit\n") do
       subject.run
     end