add first spec

.travis.yml

@@ -6,3 +6,4 @@ install: |
   sudo apt-get install crystal
 script:
   - crystal build crisp.cr
+  - crystal spec

spec/crisp/interpreter_spec.cr

@@ -0,0 +1,15 @@
+require "../helper"
+require_crisp "interpreter"
+
+describe "Crisp::Interpreter"
+  describe "#eval_string"
+    it "evaluates string of Crisp expression"
+      i = Crisp::Interpreter.new
+      result = i.eval_string "(+ 1 2)"
+      result.should be_a(Crisp::Type)
+      unwrapped = result.unwrap
+      result.should be_a(Int32)
+      result.should eq(unwrapped, 3)
+    end
+  end
+end

spec/helper.cr

@@ -0,0 +1,5 @@
+require "spec"
+
+macro require_crisp(module)
+  require "../../src/crisp/{{module}}"
+end

src/crisp/interpreter.cr

@@ -46,7 +46,15 @@ module Crisp
     end
 
     def eval_string(str)
-      print(@evaluator.eval(read(str), @env))
+      @evaluator.eval(read(str), @env)
+    end
+
+    def eval(t : Crisp::Type)
+      @evaluator.eval(t, @env)
+    end
+
+    def eval(val)
+      @evaluator.eval(Crisp::Type.new val, @env)
     end
 
     def run(filename = nil)
@@ -57,7 +65,7 @@ module Crisp
 
       while line = Readline.readline("Crisp> ", true)
         begin
-          puts eval_string(line)
+          puts kp">self.print(eval_string(line))
         rescue e
           puts e.message
         end