DSL overhaul for 1.0.0

At the moment, different problems with the current state of DSLs need to be addressed for the first official release:

• Name mangling of DL is not namespace-aware, leading to linking issues.
• No proper way of importing other DL files.
• No default value at the definition level
• No constants at the definition level, such as PI

added #23 (closed) as child task

added #24 (closed) as child task

added #25 (closed) as child task

added #26 (closed) as child task

added #28 (closed) as child task

added doing label

mentioned in merge request !2 (merged)

mentioned in commit 2f681df9

closed with merge request !2 (merged)

mentioned in issue #26 (closed)

marked the checklist item Name mangling of DL is not namespace-aware, leading to linking issues. as completed

marked the checklist item No proper way of importing other DL files. as completed

marked the checklist item No default value at the definition level as completed

marked the checklist item No constants at the definition level, such as PI as completed

The changes were implemented and tested. Here is a summary of the changes:

1. languages.el and languages.instance were merged into languages.base, which was necessary to support the requirements. Accordingly, the existing code has to be rewritten to use the new library and package.

2. EvoAl now uses a module structure to allow proper importing. Each module has a fully-qualified name, which can be used in import statements. The old use instruction is not supported anymore.

3. EvoAl, in standalone mode, now imports .dl files from its jar files. The Eclipse plugins do not support this magic yet, see #31. Therefore, the EvoAl release has a definitions folder that you have to import into Eclipse.

4. It is possible to specify constant values in .dl files: const real PI := 3.1415;

5. Attributes in .dl files can be given a default value: type foo { bar : real := PI; }

6. The base type float was renamed to real.

removed doing label

mentioned in issue #31