Common Lisp for Clojurists
Brit Butler
2013-10-10
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> whoami
PythonistaRubyist by day, Lisper by night- 27, started programming six years ago
- Cut my teeth on Scheme & SICP in '08
- No 'real' programming (larger than 100 loc) until Oct 2009
Please stop me for questions whenever.
> Talk Overview
There is a plan but I can switch styles if you want:
- Give, ya know, a lecture-ish thing and answer questions. :)
- Walk you through code from script to small lib to bigger.
- Just live code something audience suggested and narrate.
Let's start with the lecture and veer off course when ready.
> Disclaimers
You'll probably miss some things...
- Pervasive Destructuring, but there is destructuring-bind
- Lisp-1 Namespacing, but there are always macros...
- Uniform Data Structure APIs, but there are crazy people...
And so on. But Clojure and CL are complimentary tools.
> But Why Common Lisp?
Should probably just address this head on...
- Maybe the JVM isn't an option.
- Maybe you want an unopinionated language.
- Maybe you want to dig under the abstractions.
- Maybe you want to play with the wealth of CL libraries.
We can discuss this further over beers. :)
> Some Historical Perspective
Common Lisp is to Clojure as OCaml is to Scala.
CL + OCaml reached "adulthood" in the mid-90s.
Both facing off against C++ as opposed to Java...
And thus more suited to "Systems Programming".
The Ecosystems can seem dated ... like CPAN.
> The Toolset
You need: Compiler, Editor, Build Tool, Package Manager
Compiler: Just Use SBCL or CCL.
(There is ABCL if you must JVM...)
Editor: Premier editors are Emacs/slime and vim/slimv.
Build Tool: It's simple, there is only ASDF.
Package Manager: Get quicklisp. There is no substitute. :)
Lispbox is also an option.
> The Language
Common Lisp is (as far as possible) a Systems Lisp.
What I like about Lisp is that you can
feel the bits between your toes.
- Drew McDermott
Common Lisp is unopinionated, agnostic.
Lisp is a programmer amplifier.
- Martin Rodgers
> The Language: Syntax
No literal syntax for...
- Hashes/Sets
- Regexes
- Lambdas, but there's curry-compose-reader-macros
Vectors are not [1 2 3] but #(1 2 3)
Functions are passed not as foo but #'foo
> The Language: Basics
- NOTE: Having an online ANSI standard is awesome!
Many things will be clear quickly:
Other things will be stranger:
> The Language: Object Oriented
We don't actually have methods, we have generic functions.
And we have both classes *and* structs...
But usually things are fairly straightforward.
> The Language: REPL Tools
There are tons of goodies for interactive development:
- trace - because print debugging is ridiculous
- apropos - because finding the tool you need should be quick
- describe - because docs are handy things (there is also #'documentation)
- time - because checking runtime should be quick and easy
- dribble - because REPL logging can be very useful
> The Language: Packaging
Packages are _roughly_ analagous to namespaces.
File can define multiple packages, package can have code in multiple files.
Systems are analagous to a library.
Defined by a foo.asd file in your project root.
Example: cl-scrobbler
> The Language: Extensions
Much like with Clojure, you can get outside the box...
> The Language: Non-Portable Magic
Ramble here if there's time?
> The "Community"
A few notable, minimally intersecting hangouts...
> The Ecosystem
Or, "What lib do I use for X?"
- Check Cliki's recommended libs
- Ask in #lisp or use
(ql:system-apropos "my-lib")
What about learning materials?
- Start with Practical Common Lisp!
- Take language questions to the Minispec,
take library questions to QuickDocs. - There are also many quick references.
> Selected Projects: famiclom
A (wip) Nintendo Emulator in Pure CL
- 750 lines of code for the CPU, Assembly, Disassembly.
- CPU runs at ~50 Mhz on an old Core 2 Duo.
- There's a literate-style book!
> Selected Projects: coleslaw
A Static Blog Engine a la Jekyll
- 450 lines of Core, 250 lines of Plugins.
- Git-backed Markdown posts, Push to deploy.
- RSS and ATOM feeds, Code highlighting.
- Plugins for DISQUS comments, Google analytics,
LaTeX via Mathjax, Wordpress Importing, etc
> Selected Projects: cl-scrobbler
