[molf]

This is a philosophy. One which many people that write Ruby subscribe to. The fundamental idea is: create a DSL that makes it very easy to implement your application. It is what made Rails different when it was created: it is a DSL that makes expressing web applications easy.

I don't know its history well enough, but it seems to originate from Lisp. PG wrote about it before [1].

It can result in code that is extremely easy to read and reason about. It can also be incredibly messy. I have seen lots of examples of both over the years.

It is the polar opposite of Go's philosophy (be explicit & favour predictability across all codebases over expressiveness).

[1]: https://paulgraham.com/progbot.html

[dudeinjapan]

If there is one DSL which is a central abstraction of one’s entire app, used in 100s of places—this is fine.

If there is a DSL such as Rails’ URL routing, which will be the same in every app—this is also fine.

When one makes 100s of micro-DSLs for object creation, that are only ever used in one or two places—this is pure madness.