Continue implementation of compilation

content/blog/06_compiler_semantics.md

@@ -185,11 +185,26 @@ we see a variable that __isn't__ in the current environment, it must be a functi
 
 Having finished contemplating out method, it's time to define a signature:
 ```C++
-virtual void compile(const env_ptr env, std::vector<instruction>& into) const;
+virtual void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 ```
 
-Ah, but now we have to define "environment". Let's do that:
+Ah, but now we have to define "environment". Let's do that. Here's our header:
 
 {{< codeblock "C++" "compiler/06/env.hpp" >}}
 
+And here's the source file:
+
+{{< codeblock "C++" "compiler/06/env.cpp" >}}
+
+{{< todo >}}Explain the code drops. {{< /todo >}}
+
+It will also help to move some of the functions on the `binop` enum
+into a separate file. The new neader is pretty small:
+
+{{< codeblock "C++" "compiler/06/binop.hpp" >}}
+
+The new source file is not much longer:
+
+{{< codeblock "C++" "compiler/06/binop.cpp" >}}
+
 And now, we begin our implementation.