Hacker News Reader

Comment by cammsaul | Hacker News Reader

I find http://hyperpolyglot.org/lisp to be extremely useful for cases when I know what I want to do but don't remember how to do it in Elisp.

View on HN

A word of warning for Elisp hackers: the Emacs Lisp part of that resource was written by someone with a CL background. I'm seeing various examples that are not conventional Elisp. For instance, ' is used instead of #' for function quoting in various places (prevents compilation of the function) and use of eval on a form instead of apply on a list (dangerous and also prevents compilation of the form). In addition, many of these features use the cl package at runtime, which will cause the compiler to throw a warning, because it's not allowed in Emacs proper.

That said, there's a lot of information here that's very useful for the starting Elisp programmer.

>For instance, ' is used instead of #' for function quoting in various places (prevents compilation of the function) and use of eval on a form instead of apply on a list

I don't see how these are evidence of the author having "CL background". CL is pretty much identical to Emacs lisp with regards to both of these things.

Truth be told, I know nothing of CL. I do know quite a bit about Elisp, and since it's not an Elisp-ism, and the CL and Elisp columns share so much identical code (a lot from cl.el), I assumed it was a CL-ism. My bad.

the #' in CL and Elisp are not the same. Elisp is a lisp-1 vs CL 'lisp-2'. The only similarity is that #'foo expands too (function foo). In CL (function foo) looks up foo in the function namespace (and iiuc can be omitted where functions are expected) in elisp the function form is like quote except for when byte-compiling. It allows the function to be byte-compiled.

Brilliant, thank you very much!

Awesome resource.

Reply on news.ycombinator.com