Rascal 0.17.x release notes

In this post we report on the Rascal release 0.17.x, which includes all changes since the 0.16.x releases.

Release 0.17.0 - March 16th, 2020

The 0.15.x releases served as daily pre-releases for 0.17.0, while 0.16.x was a stable release which included all patches since 0.10.0. The releases between 0.10.0 and 0.16.0 have mainly been concerned with bootstrapping and minor bugfixes.

The current release 0.17.x is a step towards bootstrapping the Rascal compiler and making the new static checker (type checker) available.

The static checker:

• checks all features of Rascal
• is written in Rascal using the TypePal framework
• is activated on "project clean" and "file save"
• runs for now in the Rascal interpreter and may be slow on bigger projects (this is transitional, so bear with us)
• enables editor features such as hover-help and jump-to-definition in Eclipse, based on the state of the file after the last "save"
• using the Eclipse Preferences: Eclipse > Preferences > Rascal > Enable Rascal Compiler, type checking can be turned on or off

Also in this release significant steps have been made towards Rascal project deployment:

• In RASCAL.MF, Use Required-Libraries: |lib://myDependency| to declare projects you depend on
• Declare a project using Project-Name: projectName in RASCAL.MF
• The |lib://name| scheme always resolves to the root of a jar or target folder for a project with that name
• Eclipse, maven and Junit use the above information to configure interpreter and compiler search paths correctly
• The starting point is the JVM classpath: every RASCAL.MF file found on this path leads to a loadable library
• IDEs such as Eclipse dynamically resolve lib:// references to respective project's target folders if so required

Other notable changes:

• all static errors and warnings in the standard library have been resolved
• general code cleanup
• resolved many issues (thanks all for reporting!)
• various performance improvements