3 ms·

The source code for this is a really nice read, I just read the whole cmd/micro/micro.go like some prose. But one thing jumped at me: if err != nil && !stri

• chrisseaton 9y ago
  How could it be a pointer comparison? It's checking that the string has a prefix, not that the strings are equal.
  • throwanem 9y ago
    The prefix check in this case is used as a means of typing the error, which many Lisps do via symbols.
• codebeaker 9y ago
  A string check for an error type in a typed language is a shortcut/laziness really. There's more complex ways (which are less elegant) to typecast the error type into a "concrete" type and figure out if it's really the issue you are looking for. In Go error is an interface type that is expected to implement the `Error() string {}` method. That makes it quite trivial to implement a ErrFunctionDoesNotExist type which wraps the native "error" types returned by the lower down functions, and compare against it with a type assertion. Doing this a lot gets really old, however so maybe the author took a shortcut. If that's the case, at least it's greppable. For what it's worth there's a technique in use throughout the Go stdlib which embues the `error` type with extra methods which allows you to check the specific fault with a url.Parse9), for example https://golang.org/pkg/net/url/#Error https://golang.org/pkg/net/url/#Error
• kazinator 9y ago
  > I wonder why most modern languages don't provide symbols a la Lisp. Because their implementors don't know WTF that is.