Scala · Expert

Lesson 1 · On the house

ClassTag

Runtime arrays, ClassTag, implicitly, Array.newBuilder.

Lesson 2

TypeTag sketch

TypeTag, typeOf, erasure vs tags, reflect dependency.

Lesson 3

Higher-kinded types

F[_], mapK, kind polymorphism basics.

Lesson 4

Path-dependent types

outer.Inner, type projection #, path vs projection.

Lesson 5

Self types

self: Foo =>, cake-style wiring without extends.

Lesson 6

Value classes

extends AnyVal, allocation caveats, extension style.

Lesson 7

Phantom types

Tag types with no runtime value; units, auth states.

Lesson 8

Cake pattern

Layered traits + self types for modular deps.

Lesson 9

Parallel collections

.par, when it helps/hurts, side effects.

Lesson 10

Expert capstone

ClassTag + HKT helper + self-type + phantom + par.