4. Configuration

We will show you how to prepare your project for use with NaBL2, and write your first small specification.

4.1. Prepare your project

You can start using NaBL2 by creating a new project, or by modifying an existing project. See below for the steps for your case.

4.1.1. Start a new project

If you have not done this already, install Spoofax Eclipse, by following the installation instructions.

Create a new project by selecting New > Project... from the menu. Selecting Spoofax > Spoofax language project from the list, and click Next. After filling in a project name, an identifier, name etc will be automatically suggested. To use NaBL2 in the project, select NaBL2 as the analysis type. Click Finish to create the project.

4.1.2. Convert an existing project

If you have an existing project, and you want to start using NaBL2, there are a few changes you need to make.

First of all, make sure the metaborg.yaml file contains at least the following dependencies.

---
# ...
dependencies:
  compile:
  - org.metaborg:org.metaborg.meta.nabl2.lang:${metaborgVersion}
  source:
  - org.metaborg:org.metaborg.meta.nabl2.shared:${metaborgVersion}
  - org.metaborg:org.metaborg.meta.nabl2.runtime:${metaborgVersion}

We will set things up, such that analysis rules will be grouped together in the directory trans/analysis. Create a file trans/analysis/main.str that contains the following.

module analysis/main

imports

  nabl2shared
  nabl2runtime
  analysis/-

Add the following lines to your main trans/LANGUAGE.str.

module LANGUAGE

imports

  analysis/main

rules

  editor-analyze = analyze(desugar-pre,desugar-post)

If your language does not have a desugaring step, use analyze(id,id) instead.

Finally, we will add reference resolution and menus to access the result of analysis, by adding the following lines to editor/Main.esv.

module Main

imports

  nabl2/References
  nabl2/Menus

You can now continue to the example specification here, or directly to the language reference.

4.2. Runtime settings

4.2.1. Multi-file analysis

By default, files are analyzed independently of each other. Files can also be analyzed in the project context. This allows cross-file references, imports, et cetera. This is called multifile mode, and is configured the ESV files of a language definition. To enable multi-file mode, add the (multifile) option to the observer:

observer = editor-analyze (multifile)

4.2.2. Logging

The log output of NaBL2 analysis can be controlled by setting the runtime.nabl2.debug option in a projects metaborg.yaml.

The following debug flags are recognized:

• analysis enables summary output about the analysis; number of files analyzed and overal runtime.
• files enables output about individual files; which files are being analyed.
• collection enables output about constraint collection; a trace of the rules are applied during collection.
• timing enables output about the runtimes of different parts of the analysis.
• all enables all possible output.

For example, to enable summary output about the analysis, add the following to a projects metaborg.yaml:

runtime:
  nabl2:
    debug: analysis

4.3. Inspecting analysis results

You can debug your specification by inspecting the result of analysis, and by logging a trace of the rules that get applied during constraint generation.

The result of analysis can be inspected, by selecting elements from the Spoofax > NaBL2 Analysis the menu. For multifile projects, use the Project results, or the File results for singlefile projects.