Curriculum Idioms & ecosystem The small-interface idiom exercise 3 · mcq
The small-interface idiom
Pick the IDIOMATIC interface signature for a function that needs to read bytes from somewhere. (The smallest interface that does this in Go's stdlib has ONE method.)
TypeScript reference
About this theme
io.Reader { Read(p []byte) (n int, err error) }. One method. Go interfaces are typically tiny because implicit satisfaction rewards it — small interfaces are easy to satisfy accidentally, which is good. The community phrase: "accept interfaces, return structs." Funcs take the smallest interface they need.