aberant space

i make beer, music, and code. sometimes in that order. @aberant on twitter

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ruby drive-by: autovivification

need multi-level hashes in a hurry? (assumes 1.9)

h = Hash.new {|h,k| h[k] = Hash.new(&h.default_proc)} h["foo"]["bar"]["baz"] = 42 h["foo"] #=> {"bar"=>{"baz"=>42}}

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ruby's dusty corners: -n

if you are a perl hacker, then what this does is probably no surprise to you.  if you specify "-n" as an argument to ruby, then it wraps your code in a 'while gets() ... end' loop.

lets pretend grep didn't exist and i wanted a bit of code to loop through all my ruby files and print the lines where i was using the RUBYLIB constant.  i would create something like this.

ruby -ne "print if /RUBYLIB/" *.rb

note that there is a print and not a puts in that code.  IO#print with no arguments prints $_ which is the last line fetched by a gets or readline.    

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ruby code to break your internal interpreter

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an amazingly detailed description of the linux system calls triggered when you run "ls".

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i could give this guy a hug for neatly summing up problems with mock based testing

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apparently, given a long enough looped tape, you can convert machines as simple as Zuse's Z3 into a universal Turing machine

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cool feature of ruby 1.9 - ripper

i recently stumbled across an interesting class in the ruby 1.9 standard library - ripper.  it generates an abstract syntax tree for a given bit of ruby code.  here are a couple examples of how to use it.

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new projects - memprof-analyzer and simple-measures

memprof-analyzer is a tool that's slowly evolved as i've tried to use memprof to analyze some rails projects. if you don't know about memprof, drop what you are doing and read up about it. i think this is a game changing app for the ruby community, because memprof can finally provide some level of insight into the memory usage of the ruby interpreter.

memprof-analyzer in early alpha stage right now, but supports a few simple commands. as i find ways to make sense of the huge set of data memprof generates, it will be incorporated into the app.

simple-measures lets you describe units of measurement such as weight and volume. in testing out other similar libraries, i was surprised when they were able to convert cubic angstroms to hogsheads, but failed miserably at converting gallons to liters. simple-measures is my response to these overly complex and non extendable libs.

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simple steps you can take to adopt a more functional coding style

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sending midi sysex with core midi and ruby ffi

lately i've been trying to update my fork of midiator to be compatible with SnowLeopard and send/receive sysex messages. this is a really rough example of how to use ruby to send sysex, but it's somewhere to start. i'm eventually going to incorporate this into midiator.