adding the blocks to virtual machine and store instructions in array not list

lib/virtual/block.rb

@@ -0,0 +1,59 @@
+require_relative "object"
+
+module Virtual
+  
+  # Think flowcharts: blocks are the boxes. The smallest unit of linear code
+  
+  # Blocks must end in control instructions (jump/call/return). 
+  # And the only valid argument for a jump is a Block 
+  
+  # Blocks form a graph, which is managed by the method
+  
+  class Block < Virtual::Object
+
+    def initialize(name , method )
+      super()
+      @method = method
+      @name = name.to_sym
+      @branch = nil
+      @codes = []
+    end
+
+    attr_reader :name  , :next , :codes , :method
+    attr_accessor :branch
+    
+    def reachable ret = []
+      add_next ret
+      add_branch ret
+      ret
+    end
+
+    def add_code kode
+      @codes << kode
+      self
+    end
+
+    # returns if this is a block that ends in a call (and thus needs local variable handling)
+    def call_block?
+      return false unless codes.last.is_a?(CallInstruction)
+      return false unless codes.last.opcode == :call
+      codes.dup.reverse.find{ |c| c.is_a? StackInstruction }
+    end
+
+    private
+    # helper for determining reachable blocks 
+    def add_next ret
+      return if @next.nil?
+      return if ret.include? @next
+      ret << @next
+      @next.reachable ret
+    end
+    # helper for determining reachable blocks 
+    def add_branch ret
+      return if @branch.nil?
+      return if ret.include? @branch
+      ret << @branch
+      @branch.reachable ret
+    end
+  end
+end