The Spoofax Language Workbench Lennart Kats Eelco Visser Software - PowerPoint PPT Presentation

The Spoofax Language Workbench Lennart Kats Eelco Visser

Software Engineering implement Problem Software validate

High-level languages reduce problem/solution gap Problem HLL Machine Domain

Domain-Specific Languages Problem DSL HLL Machine Domain DSLs further reduce gap between problem domain and implementation

Example DSL:

paradigm: linguistic abstraction

making languages should be cheap

Compiler Ingredients Syntax definition concrete syntax ★ parser abstract syntax ★ generators Static semantics meta- programming error checking ★ libraries name resolution ★ meta- type analysis ★ programming Model-to-model transformation languages template express constructs in core language ★ engines Code generation translate core language models to implementation ★

Editor Services syntactic editor services semantic editor services • • syntax highlighting error marking • • syntax checking reference resolving • • outline view hover help • • bracket matching, insertion mark occurrences • • automatic indentation content completion • • syntax completion refactoring • • ... ...

Semantic Editor Services } Syntax definition Static semantics Model-to-model transformation Language workbenches Code generation [Fowler ’05] Syntactic Editor Services how can we make these things cheaply?

Language Workbench: integrated environment for language definition

Holy Grail of Software Language Definition Automatically derive efficient, scalable, incremental compiler + usable IDE from high-level, declarative language definition

Stratego SDF Eclipse IMP

Stratego Language Definition by Transformation SDF Eclipse IMP

• <spoofax screenshot: lang def and lang use in Eclipse workspace>

SDF: Declarative Syntax Definition

A syntax definition specifies a transformation from text to trees

Syntax as Transformation

Syntax as Transformation

Syntax as Transformation t r a n s f o r m

Syntax as Transformation t r a n s f o r m

Syntax as Transformation t r a n s f o r m

Semantics = transformation

Error Marking is a Transformation t r a n s f o r m

Error Marking is a Transformation t r a n s f o r m

Error Marking is a Transformation t r a n s f o r m transform

Error Marking is a Transformation t r a n s f o r m transform

Error Marking is a Transformation t r a n s f o r m transform

Outline View is a Transformation transform

Hyperlinking is a Transformation transform

Content Completion is a Transformation transform transform

Code Generation is a Transformation t r a n s f o r m

Need for single, unified language specification: • Editor services • Model transformations • Code generation

Stratego: Rewriting Language

Rewrite rules Strategies

Error Marking with Rewrite Rules

Error Marking with Rewrite Rules

Error Marking with Rewrite Rules t Origin tracking r a n s f o r m transform

Analysis with Rewrite Rules

Code Generation with Rewrite Rules

Conclusion • Co-evolution of language and IDE • Pure and declarative syntax definition • Language definition by transformation • www.spoofax.org: papers, tour, download