diff --git a/Gemfile b/Gemfile
index 50d9a01..9c83ef4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,6 +4,7 @@ gem "rake"
 
 gem "salama-reader" , :path => "."
 gem "citrus" , :github => "salama/citrus" , :branch => "gemspec-readme"
+gem "ast" , :path => "../ast"
 
 # Add dependencies to develop your gem here.
 # Include everything needed to run rake, tests, features, etc.
diff --git a/Gemfile.lock b/Gemfile.lock
index fe0aa4a..00a40c3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,6 +11,11 @@ PATH
     salama-reader (0.2.0)
       citrus (~> 3.0.3)
 
+PATH
+  remote: ../ast
+  specs:
+    ast (2.1.0)
+
 GEM
   remote: http://rubygems.org/
   specs:
@@ -31,9 +36,13 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  ast!
   citrus!
   codeclimate-test-reporter
   minitest
   rake
   rubygems-tasks
   salama-reader!
+
+BUNDLED WITH
+   1.10.5
diff --git a/lib/parser/bosl.citrus b/lib/parser/bosl.citrus
index f0e2bf0..12564ea 100644
--- a/lib/parser/bosl.citrus
+++ b/lib/parser/bosl.citrus
@@ -20,11 +20,11 @@ grammar Bosl
   end
 
   rule name_expression
-     (name:([a-z_] [a-zA-Z0-9_]*) space*) { Ast::NameExpression.new(capture(:name).to_str)}
+     (name:([a-z_] [a-zA-Z0-9_]*) space*) { capture(:name).to_str}
   end
 
-  rule module_name_expression
-     (name:([A-Z] [a-zA-Z0-9_]*) space*) { Ast::ModuleName.new(capture(:name).to_str)}
+  rule aspect_name_expression
+     (name:([A-Z] [a-zA-Z0-9_]*) space*) { s(:aspect , capture(:name).to_str)}
   end
 
   rule digits
@@ -32,17 +32,17 @@ grammar Bosl
   end
 
   rule integer_expression
-    (digits space*) { Ast::IntegerExpression.new(to_str.to_i) }
+    (digits space*) { s(:int , to_str.to_i) }
   end
 
   rule string_expression
     #"'" (/.*/ !"'") "'"
-     ('"' str:(!'"' .)* '"') {Ast::StringExpression.new(capture(:str).to_str) }
+     ('"' str:(!'"' .)* '"') {s(:string , capture(:str).to_str) }
   end
 
   rule basic_expression
     name_expression | integer_expression  |
-    module_name_expression | string_expression
+    aspect_name_expression | string_expression
   end
 
   rule keyword_begin    'begin'  space* end
@@ -54,21 +54,20 @@ grammar Bosl
   rule keyword_if       'if'       end
   rule keyword_rescue   'rescue' space* end
   rule keyword_return   'return' space* end
-  rule keyword_module   'module' space*  end
+  rule keyword_aspect   'aspect' space*  end
   rule keyword_unless   'unless' space* end
-  rule keyword_until    'until'  space* end
   rule keyword_while    'while'  space* end
 
   rule keyword_nil
-    ('nil'    space* ){ Ast::NilExpression.new }
+    ('nil'    space* ){ s(:nil) }
   end
 
   rule keyword_false
-    ('false'  space*) { Ast::FalseExpression.new }
+    ('false'  space*) { s(:false) }
   end
 
   rule keyword_true
-    ('true'   space*) { Ast::TrueExpression.new }
+    ('true'   space*) { s(:true) }
   end
 
   # this rule is just to make sure identifiers can't be keywords. Kind of duplication here, but we need the
@@ -152,15 +151,14 @@ grammar Bosl
 
   rule call_site
     (field_expression  argument_list space?) {
-      Ast::CallSiteExpression.new(capture(:field_expression).value ,
-                          capture(:argument_list).value  )
+      s(:call , capture(:field_expression).value , capture(:argument_list).value  )
     }
   end
 
   rule field_expression
     (basic_expression "." name_expression  space?) {
-      Ast::FieldExpression.new(capture(:basic_expression).value ,
-                          capture(:name_expression).value.name )
+      s(:field , capture(:basic_expression).value ,
+                          capture(:name_expression).value )
     }
   end
 
@@ -197,21 +195,20 @@ grammar Bosl
 
   rule typed_arg
     (type name_expression) {
-      Ast::TypedName.new(capture(:type).value , capture(:name_expression).value.name)
+      s(:type , capture(:type).value , capture(:name_expression).value)
     }
   end
 
   rule variable_definition
     (typed_arg ("=" space* value_expression)?) {
-      type = capture(:typed_arg).value
       value = capture(:value_expression) ? capture(:value_expression).value : nil
-      var = Ast::VariableDefinition.new(type.type , type.name ,  value)
+      s(:variable , capture(:typed_arg).value , value )
     }
   end
 
   rule assignment
     (name_expression "=" space* value_expression){
-    Ast::AssignmentExpression.new( capture(:name_expression).value.name , capture(:value_expression).value)
+    s(:assign ,  capture(:name_expression).value.to_sym , capture(:value_expression).value)
     }
   end
 
@@ -219,7 +216,7 @@ grammar Bosl
     (keyword_if left_parenthesis value_expression right_parenthesis
     body
     keyword_end)  {
-    Ast::IfExpression.new( capture(:value_expression).value  , capture(:body).value , nil)
+      s(:if ,  s(:cond , capture(:value_expression).value )  , s(:then , capture(:body).value) )
     }
   end
 
diff --git a/lib/parser/salama.rb b/lib/parser/salama.rb
index 41521bb..1b48639 100644
--- a/lib/parser/salama.rb
+++ b/lib/parser/salama.rb
@@ -1,10 +1,11 @@
-
-require 'ast/expression'
+require "ast"
 
 module Parser
 
   # obviously a work in progress !!
 
+  Citrus::Match.include AST::Sexp
+
   Citrus.require "parser/bosl"
 
 end
diff --git a/test/parser_helper.rb b/test/parser_helper.rb
index c4aba26..aacd6c1 100644
--- a/test/parser_helper.rb
+++ b/test/parser_helper.rb
@@ -1,7 +1,9 @@
 require_relative "setup"
+require "ast"
 
 # Included in parser test will create tests methods
 module ParserHelper
+  include AST::Sexp
 
   def self.included(base)
 #    base.send :include, InstanceMethods  #provides helpers and setup
diff --git a/test/unit/test_basic.rb b/test/unit/test_basic.rb
index 184c131..274d932 100644
--- a/test/unit/test_basic.rb
+++ b/test/unit/test_basic.rb
@@ -6,62 +6,62 @@ class TestBasic < MiniTest::Test
 
   def test_true
     @input    = 'true  '
-    @output = Ast::TrueExpression.new()
+    @output = s(:true)
     check :keyword_true
   end
 
   def test_false
     @input    = 'false '
-    @output = Ast::FalseExpression.new()
+    @output = s(:false)
     check :keyword_false
   end
 
   def test_nil
     @input    = 'nil '
-    @output = Ast::NilExpression.new()
+    @output = s(:nil)
     check :keyword_nil
   end
 
   def test_integer
     @input    = '42 '
-    @output = Ast::IntegerExpression.new(42)
+    @output = s(:int , 42)
     check :integer_expression
   end
 
   def test_name
     @input    = 'foo '
-    @output = Ast::NameExpression.new('foo')
+    @output = 'foo'
     check :name_expression
   end
 
   def test_name_underscode_start
     @input    = '_bar '
-    @output = Ast::NameExpression.new('_bar')
+    @output = '_bar'
     check :name_expression
   end
 
   def test_name_underscode_middle
     @input    = 'foo_bar '
-    @output = Ast::NameExpression.new('foo_bar')
+    @output = 'foo_bar'
     check :name_expression
   end
 
   def test_module_name
     @input    = 'FooBar '
-    @output = Ast::ModuleName.new("FooBar")
-    check :module_name_expression
+    @output = s(:aspect , "FooBar")
+    check :aspect_name_expression
   end
 
   def test_string
     @input    = '"hello"'
-    @output =  Ast::StringExpression.new('hello')
+    @output =  s(:string , 'hello')
     check :string_expression
   end
 
   def test_string_escapes
     out = 'hello  \nyou'
     @input    = '"' + out + '"'
-    @output =  Ast::StringExpression.new(out)
+    @output =  s(:string , out)
     check :string_expression
   end
 
diff --git a/test/unit/test_call_site.rb b/test/unit/test_call_site.rb
index 4cb9a95..9d39468 100644
--- a/test/unit/test_call_site.rb
+++ b/test/unit/test_call_site.rb
@@ -5,38 +5,38 @@ class TestCallSite < MiniTest::Test
 
   def test_single_self
     @input = 'self.foo(42)'
-    @output = Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::NameExpression.new(:self),:foo), [Ast::IntegerExpression.new(42)] )
+    @output = s(:call, s(:field , "self" , "foo") , [s(:int, 42)])
     check :call_site
   end
 
   def test_single_name
     @input = 'my_my.foo(42)'
     @parse_output = {:receiver=>{:name=>"my_my"}, :call_site=>{:name=>"foo"}, :argument_list=>[{:argument=>{:integer=>"42"}}]}
-    @output = Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::NameExpression.new(:my_my),:foo), [Ast::IntegerExpression.new(42)] )
+    @output = s(:call, s(:field, "my_my", "foo"), [s(:int, 42)])
     check :call_site
   end
 
   def test_int_receiver
     @input = '42.put()'
-    @output = Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::IntegerExpression.new(42),:put), [] )
+    @output = s(:call, s(:field, s(:int , 42) ,  "put") , [])
     check :call_site
   end
 
   def test_string_receiver
     @input = '"hello".puts()'
-    @output = Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::StringExpression.new("hello"),:puts), [] )
+    @output = s(:call , s(:field , s(:string , "hello") , "puts") , [])
     check :call_site
   end
 
   def test_call_site_2
     @input = 'self.baz(42, foo)'
-    @output = Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::NameExpression.new(:self),:baz), [Ast::IntegerExpression.new(42),Ast::NameExpression.new(:foo)] )
+    @output = s(:call ,s(:field , "self", "baz") ,  [s(:int, 42), "foo"])
     check :call_site
   end
 
   def test_call_site_3
     @input = 'self.baz(42, foo , bar)'
-    @output = Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::NameExpression.new(:self),:baz), [Ast::IntegerExpression.new(42),Ast::NameExpression.new(:foo),Ast::NameExpression.new(:bar)] )
+    @output = s(:call,  s(:field, "self", "baz"), [s(:int, 42), "foo", "bar"])
     check :call_site
   end
 
diff --git a/test/unit/test_conditional.rb b/test/unit/test_conditional.rb
index 913791d..2e29de5 100644
--- a/test/unit/test_conditional.rb
+++ b/test/unit/test_conditional.rb
@@ -5,19 +5,19 @@ class TestConditional < MiniTest::Test
 
   def test_assignment
     @input = "myvar = 42"
-    @output = Ast::AssignmentExpression.new(:myvar,Ast::IntegerExpression.new(42))
+    @output = s(:assign, :myvar, s(:int, 42))
     check :assignment
   end
 
   def test_variable_declaration
     @input = "int myvar"
-    @output = Ast::VariableDefinition.new(:int,:myvar,nil)
+    @output = s(:variable,s(:type, "int", "myvar"), nil)
     check :variable_definition
   end
 
   def test_variable_declaration_value
     @input = "int myvar = 42"
-    @output = Ast::VariableDefinition.new(:int,:myvar,Ast::IntegerExpression.new(42))
+    @output = s(:variable,   s(:type, "int", "myvar"),   s(:int, 42))
     check :variable_definition
   end
 
@@ -27,7 +27,9 @@ if( 1 )
   int num = 42
 end
 HERE
-    @output = Ast::IfExpression.new(Ast::IntegerExpression.new(1), [Ast::VariableDefinition.new(:int,:num,Ast::IntegerExpression.new(42))],nil)
+    @output = s(:if,   s(:cond,     s(:int, 1)),   s(:then, [s(:variable,
+                                              s(:type, "int", "num"),
+                                              s(:int, 42))]))
     check :conditional
   end
 
@@ -37,7 +39,9 @@ if(var)
   42.add(5)
 end
 HERE
-    @output = Ast::IfExpression.new(Ast::NameExpression.new(:var), [Ast::CallSiteExpression.new(Ast::FieldExpression.new(Ast::IntegerExpression.new(42),:add), [Ast::IntegerExpression.new(5)] )],nil)
+    @output = s(:if,
+                s(:cond, "var"),
+                s(:then, [s(:call, s(:field, s(:int, 42), "add"), [s(:int, 5)])]))
     check :conditional
   end
 
@@ -51,7 +55,7 @@ end
 HERE
     @input.chop!
     @parse_output = {:if=>"if", :conditional=>{:l=>{:integer=>"3"}, :o=>"== ", :r=>{:nil=>"nil"}}, :if_true=>{:expressions=>[{:integer=>"3"}], :else=>"else"}, :if_false=>{:expressions=>[{:integer=>"4"}], :end=>"end"}}
-    @output = Ast::IfExpression.new(Ast::OperatorExpression.new("==", Ast::IntegerExpression.new(3),Ast::NilExpression.new()), [Ast::IntegerExpression.new(3)],[Ast::IntegerExpression.new(4)] )
+    @output = nil
     @root = :conditional
   end
 
@@ -63,7 +67,7 @@ end
 HERE
     @input.chop!
     @parse_output = {:if=>"if", :conditional=>{:l=>{:integer=>"3"}, :o=>"== ", :r=>{:nil=>"nil"}}, :if_true=>{:expressions=>[{:integer=>"3"}], :else=>"else"}, :if_false=>{:expressions=>[{:integer=>"4"}], :end=>"end"}}
-    @output = Ast::IfExpression.new(Ast::OperatorExpression.new("==", Ast::IntegerExpression.new(3),Ast::NilExpression.new()), [Ast::IntegerExpression.new(3)],[Ast::IntegerExpression.new(4)] )
+    @output = nil
     @root = :conditional
   end