Lectures

We break down generics in Go “without magic”: what a type parameter T and the constraint any are, how to read signatures like func First [ T any ]( xs [] T), how type inference works, how to return the zero value for T, and we also write practical utilities Ptr and Must and simple generic types Box and Stack. At the end: a type-substitution reading scheme and common beginner mistakes.

We break down why Go generics need constraints: how any means “any type” but does not grant operations like == or +, and how comparable enables comparison and using a type as a key in map. In practice, we write universal utilities Contains, Unique, CountBy, and GroupBy, and also discuss a subtlety of comparability through interfaces in Go 1.25.

Let’s break down why you might want to use the standard Go packages slices, maps, and cmp: how they express intent instead of “manual” for loops, simplify common operations (cloning, sorting, deleting a range, comparing, copying), how they relate to generics (signatures like S ~[]E and M ~map[K]V), and how to build stable output on top of a map via maps.Keys + slices.SortFunc + cmp.Compare. At the end: typical mistakes and how to avoid them.

We break down anti-patterns of using generics in Go: when abstractions add noise instead of value, why the any + type assertion combo turns compile-time errors into runtime risks, and how to “treat” such spots with clear domain functions or the standard packages slices/ maps/ cmp. At the end — a cheat sheet “symptom → replacement”, a decision flowchart, and common mistakes.

We break down how generics in Go help you write readable, “intent-driven” code: sorting via slices.SortFunc and cmp.Compare, working with slices and maps via slices/ maps, stabilizing output from map via keys and slices.Sort, plus two small generic helpers ( Filter[T] and GroupBy) using a mini “task list” app as an example.