miniblog.

tap> is an elegant Clojure debugging feature: it passes the argument to any functions registered with add-tap. You might set up a custom printer for your data type, or save values for later examination, and you can easily disable the tap too.

Twitter treats #foo and $bar as special syntax due to emergent behaviour of users. I keep seeing similar emergent features in other domains, e.g. airport wifi using '_Foo Wifi' to ensure it's sorted first. Ideally there'd be a priority flag, so a printer is never shown first.

I spent a while implementing a pretty-printer in elisp, only to realise that ielm already has a fine pretty-printer. Turns out that pp-to-string is built-in to Emacs! (I missed this initially because of the short name: I only found cl-prettyprint.)