Vampire methods
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The document discusses generating a local CatMatcher class using macros in Scala. It describes creating matcher methods for properties like name, age, and kitten that take expressions to match against. It also discusses challenges like not having access to TypeTags in macros and using reflection instead of structural types for matching.
![Inception matcher
new constraint =>
new matcher function
name/age/kitten methods
list of c.Expr[_]](https://image.slidesharecdn.com/vampire-methods-131009074938-phpapp01/85/Vampire-methods-17-320.jpg)
![Mirror, mirror
structural type =>
reflection :-(
// age
// matchA[Cat].age(6)
// Int](https://image.slidesharecdn.com/vampire-methods-131009074938-phpapp01/85/Vampire-methods-18-320.jpg)
Vampire methods
- 2. Can you do this?
- 4. Kittens!
- 5. Kittens! Generate a local class!
- 7. Paradise plugin Just for quasi-quotes
- 9. Batman
- 12. Let’s dive
- 13. Grab the Cat TypeTag not accessible in a macro!
- 14. Wash the Cat
- 15. Inception matcher Builder pattern Matcher methods // CatMatcher
- 16. Inception matcher Cat matcher Internal state
- 17. Inception matcher new constraint => new matcher function name/age/kitten methods list of c.Expr[_]
- 18. Mirror, mirror structural type => reflection :-( // age // matchA[Cat].age(6) // Int
- 19. Yo, I heard you like macros No structural type!
- 20. Yo, I heard you like macros Annotation code // @fieldMatcherBody(expected => cat.age must_== expected) // val expected = 6 // cat.age must_== expected
- 21. Yo, I heard you like macros extract parameter/body
- 22. Transformers // 6 // `prefix` represents an equivalent of // `this` for normal instance methods // body: // CatMatcher.this.addMatcher((_:Cat).age must_== arg)
- 25. Can you do this? YES !!!
- 26. Thank you! If you followed that far…