programmers are fallible people, who sometimes stay up late coding at 3am, when they can hardly see the screen anymoreproblem. In short you are depending on the caller to honor your contract and do the right thing even though we often do exactly the wrong thing. Even when you are the caller, sometimes you don't honor that contract. Then a month later you are doing that print statement and die or perhaps the debugger dance again. All of this because of one night when your judgement lapsed. Companies will often develop elaborate style guides, testing strategy, and code-review cultures to prevent this, but in the end most developers I know come to love throwing exceptions... unless they are coding in erlang. This is because of two elements of the erlang language design = "
- Pattern Matching
- and Fail Fast.
The combination of Pattern Matching and Fail Fast in erlang forces the programmer to honor the contract, whether he wants to or not. This is one case where Erlang follows the "Do What I Need Not What I Want" principle in a language properly.