Implicits Revisited

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" summary

An empirical study mines 7,280 projects (18M LOC, 8M implicit call sites, 370k implicit declarations) and finds implicits pervasive but error-prone: name-based resolution causes shadowing and local coherence ambiguities, implicit conversions and wildcard imports hide surprising bindings. Scala 3 redesign replaces ad-hoc implicits with Givens and a summon API, models conversions via a Conversion type, adds explicit selectors like import given and import-by-type, and provides automatic rewrites plus dotty-based tooling for gradual migration toward safer, more predictable implicit term synthesis.

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" chapters (15)

1. 0:00Start
2. 3:20Why Did the Language Have Implicit Conversions
3. 4:55Implicit Parameters
4. 5:48Scala Object-Oriented Languages
5. 6:52Basics of Implicit Parameters
6. 9:07The Implicit Argument Must Be Accessible at the Point of Call by a Simple Identifier
7. 9:20Locality
8. 11:59Mistakes
9. 14:11Local Coherence
10. 16:45Implicit Conversions
11. 23:02Scala 3
12. 30:10The Parameter Clauses
13. 32:36Type Classes
14. 36:22Imports
15. 39:55Migration

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