I am glad to share with you an excellent Bachelor's thesis written by Philipp Gabler and supervised by me. The topic is fascinating as it discusses the features of the programming language Scala to support the design of DSLs. It includes a case-study on our modeling language for model-based testing.
Philipp Gabler, Designing Embedded Domain-Specific Languages in Scala: a Case Study with Action Systems, Bachelor's Thesis, Graz University of Technology, Institute for Software Technology, June 2015.
Here is the PDF for download.