moved nodes to parser (one more layer) and fixed tests. also adds assignment

lib/vm/nodes.rb

@@ -1,105 +0,0 @@
-module Vm
-  
-  class Expression
-    # evey Expression has a eval function that returns a value
-    def eval 
-      raise "abstract"
-    end
-    def compare other , attributes
-      attributes.each do |a|
-        left = send(a)
-        right = other.send( a)
-        return false unless left.class == right.class 
-        return false unless left == right
-      end
-      return true
-    end
-  end
-
-  class IntegerExpression < Expression
-    attr_reader :value
-    def initialize val
-      @value = val
-    end
-    def == other
-      compare other , [:value]
-    end
-    def eval(context, builder)
-      builder.mov "r0" , value
-    end
-  end
-
-  class NameExpression < Expression
-    attr_reader  :name
-    def initialize name
-      @name = name
-    end
-    def == other
-      compare other ,  [:name]
-    end
-    def eval(context, builder)
-      param_names = context[:params] || []
-      position    = param_names.index(name)
-      raise "Unknown parameter #{name}" unless position
-      builder.iload position
-    end
-  end
-
-  class FuncallExpression < Expression
-    attr_reader  :name, :args
-    def initialize name, args
-      @name , @args = name , args
-    end
-    def == other
-      compare other , [:name , :args]
-    end
-    def eval(context, builder)
-      args.each { |a| a.eval(context, builder) }
-      types = [builder.int] * (args.length + 1)
-      builder.invokestatic builder.class_builder, name, types
-    end
-  end
-
-  class ConditionalExpression < Expression
-    attr_reader  :cond, :if_true, :if_false
-    def initialize cond, if_true, if_false
-      @cond, @if_true, @if_false = cond, if_true, if_false
-    end
-    def == other
-      compare other , [:cond, :if_true, :if_false]
-    end
-    def eval(context, builder)
-      cond.eval context, builder
-
-      builder.ifeq :else
-
-      if_true.eval context, builder
-      builder.goto :endif
-
-      builder.label :else
-      if_false.eval context, builder
-
-      builder.label :endif
-    end
-  end
-
-  class FunctionExpression < Expression
-    attr_reader  :name, :params, :block
-    def initialize name, params, block
-      @name, @params, @block = name, params, block
-    end
-    def == other
-      compare other , [:name, :params, :block]
-    end
-    def eval(context, builder)
-      param_names = [params].flatten.map(&:name)
-      context[:params] = param_names
-      types = [builder.int] * (param_names.count + 1)
-
-      builder.public_static_method(self.name, [], *types) do |method|
-        self.block.eval(context, method)
-        method.ireturn
-      end
-    end
-  end
-end