Nils are a very bad code smell. They come from C's null, which is a billion dollar mistake[1], according to its creator: Tonny Hoare. Specially now that we have monads[2, 3].
Scala's standard library provides very helpful information on how to replace null with its Maybe class (called Option in Scala). Just take a peek into their collections library[4], and search for Option.
Nils are a very bad code smell. They come from C's null, which is a billion dollar mistake[1], according to its creator: Tonny Hoare. Specially now that we have monads[2, 3].
Do you have a source for this? I was under the impression nil was directly taken from Smalltalk, which derived it from Lisp.
The null reference was invented by C.A.R. Hoare in 1965 as part of the Algol W language. Hoare later (2009) described his invention as a "billion-dollar mistake":[10][11]
Nil was a part of Lisp 1, which is why I was confused. It predates Algol W by seven years. As null references and nil are somewhat different beasts, I'm not sure the criticism "billion dollar mistake" applies fully.
Do you have a source for this? I was under the impression nil was directly taken from Smalltalk, which derived it from Lisp.