  Metamodel-based DSL development in language workbenches like Xtext allows
language engineers to focus more on metamodels and domain concepts rather than
grammar details. However, the grammar generated from metamodels often requires
manual modification, which can be tedious and time-consuming. Especially when
it comes to rapid prototyping and language evolution, the grammar will be
generated repeatedly, this means that language engineers need to repeat such
manual modification back and forth. Previous work introduced GrammarOptimizer,
which automatically improves the generated grammar using optimization rules.
However, the optimization rules need to be configured manually, which lacks
user-friendliness and convenience. In this paper, we present our vision for and
current progress towards a language workbench that integrates
GrammarOptimizer's grammar optimization rules to support rapid prototyping and
evolution of metamodel-based languages. It provides a visual configuration of
optimization rules and a real-time preview of the effects of grammar
optimization to address the limitations of GrammarOptimizer. Furthermore, it
supports the inference of a grammar based on examples from model instances and
offers a selection of language styles. These features aim to enhance the
automation level of metamodel-based DSL development with Xtext and assist
language engineers in iterative development and rapid prototyping. Our paper
discusses the potential and applications of this language workbench, as well as
how it fills the gaps in existing language workbenches.
