Verisons

The Workflow Description Language has two concepts of versions within the project:

• The WDL language has a two-number version (e.g., 1.2). An increase in the minor (second) version number (e.g., 1.1 to 1.2) indicates the addition of, or non-breaking changes to, the language or standard library functions. An increase in the major (first) version number (e.g., 1.0 to 2.0) indicates that breaking changes have been made.

• The WDL specification has a three-number version (e.g., 1.2.0). The specification version tracks the language version, but there may also be patch releases (indicated by a change to the patch, or third, version number) that include fixes for typos, additional examples, or non-breaking clarifications of ambiguous language.

In general, users of WDL only need to care about the version of the WDL language—you'll rarely, if ever, need to care about the version of the specification itself.

Upgrading

If you're interested in learning more about the finer details of upgrading between versions, such as what features new versions introduce, common pitfalls of upgrading, and how to get help, see the Upgrade guide in the Reference section.

Version specification

The WDL version is a statement that appears at the top of a WDL document—when included, it must be the first non-comment within the document.

NOTE

Technically, the version statement is not required, but it is highly recommended that you do include it in all of your WDL documents. Omission of the version statement defaults to a very early version of the WDL specification (draft-2).

You can specify the version of your WDL document like so:

version 1.2

# ... other document contents ...

Compatability considerations

Documents may only import other WDL documents of the same version. This is because the imported documents are effectively comingled within their importer's context and processed holistically (instead of, for example, being compiled independently).