Go Fully Functional and Take Your Legacy Code with You!
summary
Promised outcome: a mechanical four‑step migration: plan test build refactor applied to a concrete example (a qualification pipeline that reads CSVs, computes scores with coefficients, and indexes into Elasticsearch). Impure functions become effect types: wrap impure code in IO or use Option/Either for partials/errors, convert eager Future via IO, and isolate blocking onto thread pools (or use ZIO’s blocking). Regression protection uses golden master regression tests. Tooling: Scala + cats IO, Monix or ZIO, test frameworks and IDE refactor support.
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chapters (43)
- 0:00Introduction
- 0:47Who am I
- 1:20Agenda
- 2:24Functional Programming
- 3:19Function Signature
- 4:20Scala
- 5:13Java
- 6:33Reusability
- 7:12Hurdles
- 8:58Example
- 10:16Domain Overview
- 11:15Migration Method
- 12:31Tools
- 13:22Planification
- 14:37Legacy Project
- 15:16Executive Architecture
- 20:07Pipeline
- 21:50Regression Test
- 23:28Build in the Built
- 24:22Qualification
- 25:35TDD
- 26:48Modify Existing Code
- 28:29Partial Functions
- 29:15Mana
- 29:32Handling Errors
- 30:30Handling Side Effects
- 31:13Other Implementations
- 32:02Handling impure code
- 33:00Code that cannot be changed
- 33:35Interfacing problem
- 34:10Future
- 35:40Synchronous Call
- 36:27Blocking Call
- 36:57Handling Blocking Calls
- 40:33Synchronous Calls
- 41:04Using Future
- 42:01Callbacks
- 43:55Services
- 46:50Why are frameworks a problem
- 47:22Generate the future
- 48:12Go beyond
- 49:08More advanced tools
- 51:05Conclusion
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