Week 2.1: Transformation with Rewrite Rules

Homework
November 13, 2020

In this week’s homework assignments we explore program transformation using rewrite rules in Stratego.

Making Stratego Assignments in Spoofax

In order to make the Stratego assignments in Spoofax, you can use the project you set up for Statix. Apply the following adaptations.

Solution Directory

For each assignment create a directory with the SDF3 file that you can copy from WebLab, and the Stratego solution that you create based on the template from WebLab. Also copy the tests from Your Tests into an SPT file.

Syntax

In the main syntax definition file import the solution.sdf3 from WebLab. For example:

imports homework/week2-1/w1-01/solution-def

You may have to rename the module name.

Transform Strategy

In the main Stratego file in the /trans/ directory of your project import your Stratego solution, i.e. something like:

imports homework/week2-1/w1-01/solution

Add the following rules:

rules // Transform

  editor-transform:
    (node, _, _, path, project-path) -> (filename, result)
    with
      filename := <guarantee-extension(|"aterm")> path
    ; result   := <transform>node

  editor-transform-pp:
    (node, _, _, path, project-path) -> (filename, result)
    with
      filename := <guarantee-extension(|"trans.sol")> path
    ; result   := <transform; pp-debug>node

Transform Menu

In editor/Syntax.esv extend the menus of the language with:

  menu: "Transform" (openeditor)
    action: "Transform"     = editor-transform-pp (source)
    action: "Transform AST" = editor-transform (source)