Building a transpiler

The general approach to design transpilers has been described in the article How to write a transpiler.

In general these are the steps:

• The original code is parsed, obtaining the original AST (see Building parsers)

• Transformations are performed to go from the original AST to the target AST (see AST Transformations). If necessary, we can add intermediate transformation steps.

• Target code is generated from the target AST (see Building code generators)

For example, suppose we want to translate RPG into Java:

• We will use an RPG Parser, obtaining an RPG AST.

• We will implement AST transformations to transform the RPG AST into a Java AST, defined using e.g. Kolasu. The Java AST specifically is a component that Strumenta has developed and can license. However, it's also possible to build another one independently, using Kolasu or other StarLasu libraries.

• We will use a code generator to generate Java code from the Java AST. The code generator could be a pre-built component, too, or we may develop it with support from StarLasu and possibly other libraries (e.g. a templating engine).