title: Generate output along with recursive descent parser
body: <p>Writing simple parsers are trivial and I have implemented several over the years. In college, we also had to write one. But we never had to generate meaningful output using this method; <strong>we never learned how to create a back end.</strong></p>
  
  <p>If I have a working recursive descent parser for a simplified Pascal and I wanted to translate the code to C++, how would I go about doing this? I dont see a need for an intermediate step such as generating an abstract syntax tree.</p>
  
  <p><strong>So how do I go about outputting the compiled or translated code?</strong> The only useful example I have found of this is in Jack Crenshaw's tutorial but it focuses more on the front end, as does most other resources. The relationship between my parser code and my grammar is very obvious. What about the relationship between the parsers methods and the outputting? My parser method for a function declaration can relate to exactly one EmitLn(<em>C++ code here</em>) call. But what about parser methods that aren't that easy, such as expressions. Expressions are broken down to possibly many more calls, so that alludes to the need of a Emit() function that allows me to break down the output code for an expression piece by piece. <strong>Is there any boiler plate code for outputting code,</strong> such as the EmitLn function in Jack Crenshaw's Lets Build a Compiler? This also shows me I need to maintain a basic symbol table, another thing that is often omitted in most examples. </p>
  
  <p>Am I right? What else should I know? Any tips/suggestions, or resources? My big question is, there are so many tutorials out there for compiler front ends, but how about some explanation on the back end? I can parse languages, now I want to evolve that into being able to translate and compile them into other languages.</p>