DenkzeitWiki

Clojure Idioms

• Calling method in Java that mutates passed argument
  • use Java's classes
  • use clojure.contrib.repl-utils.show to reflect on Java-API
    
  
  
• proxy'ing a final class
  
  
• http://blog.fogus.me/2010/03/23/clojures-mini-languages/
  
  
• http://kotka.de/blog/2010/04/Did_you_know_I.html
  
  
• The Ins and Outs of Clojure: Part One - how to perform file-I/O in Clojure

• http://www.markhneedham.com/blog/2011/07/10/clojure-language-as-thought-shaper/
  • http://eaipatterns.com/PipesAndFilters.html

Sequences

• ClojureSequences
• http://onclojure.com/2009/03/04/dorun-doseq-doall/
  • use 'doseq' if you '(dorun (map...))' a lot...
  
  
• http://stackoverflow.com/questions/1147975/in-clojure-when-should-i-use-a-vector-over-a-list-and-the-other-way-around
  • use Vector
    
  
  
• http://www.infoq.com/articles/in-depth-look-clojure-collections
  
  
• fastest way to remove nils

Namespaces

• Exploring Clojure (Lisp on the JVM) - Part 4: Not Your Daddy's Namespaces
  • http://groups.google.com/group/clojure/browse_thread/thread/750c8669d3e718ca

Unlike CL, symbols are just names, with no associated values. The things that are more like symbols from that perspective in Clojure are vars, and it is vars that are interned in namespaces. Two symbols with the same name can be distinct objects. A namespace is not a set of symbols but a set of mappings from symbols to references - either vars or classes.

This separation of concerns is an important part of how Clojure is a Lisp-1 while still supporting defmacro semi-hygienically. The reader reads plain symbols and does no interning. The compiler resolves names (symbols) in the compilation namespace in order to find vars/classes. def interns new vars, and import/refer/use can make new mappings.

• http://ociweb.com/jnb/jnbMar2009.html#Namespaces
  
  
• What's the name of my space?
  
  
• http://onclojure.com/2010/02/17/managing-namespaces/

loaded or standalone script? -> Scripted Main

• http://rosettacode.org/wiki/Scripted_Main
  
• http://www.ociweb.com/mark/clojure/ClojureSnake.html

  ; Only run the application if this is being run as a script,
 ; not if loaded in a REPL with load-file.
 ; When run as a script, the path to this file
 ; will be a command-line argument.
 (if *command-line-args* (main))

Note: This does not work if the standalone-script does not get any parameters passed.

Commandline

• http://jakemccrary.com/blog/2011/04/12/command-line-arguments-in-clojure.html

Data types / defrecord, deftype, reify, protocol, proxy

• ADTs in Clojure
  
• http://cemerick.com/2011/07/05/flowchart-for-choosing-the-right-clojure-type-definition-form/

Symbols

• http://stackoverflow.com/questions/1175920/explain-clojure-symbols
• http://stackoverflow.com/questions/1162989/what-is-the-difference-between-procedure-and-procedure-in-lisp-clojure
• http://stackoverflow.com/questions/1527548/why-does-clojure-have-keywords-in-addition-to-symbols
  
• http://stackoverflow.com/questions/2320348/symbols-in-clojure

#clojure IRC channel

• http://clojure-log.n01se.net/date/2009-07-15.html

 Chouser: ,(some #{'c} '(a b c)) 
 clojurebot: c 
 gko: why , in front of your samples?
 ataggart: it tells clojurebot to execute it 

Keyword Arguments

• http://stuartsierra.com/2010/01/15/keyword-arguments-in-clojure

Performance

• http://www.innoq.com/blog/st/2010/04/clojure_performance_guarantees.html

SoftwareTransactionalMemory

• http://squirrel.pl/blog/2010/07/13/clojure-alter-vs-commute/

Compiler

• The issue is not single-pass vs multi-pass. It is instead, what constitutes a compilation unit, i.e., a pass over what?
  • Rich Hickey, why single-pass compiler