Slides for TRLab Erlang workshop

These are the slides I prepared for the last session of the workshop.

A page about the wide finder

I have published the page of wide finder, which was created for a group discussion on Erlang.

The problem of wide finder was coined by Tim Bray, and is summarized in http://www.tbray.org/ongoing/When/200x/2007/09/20/Wide-Finder

The task is to read an Apache logfile and figure out which pages have been fetched the most.

The reference Ruby code

# 11 lines

counts = {}
counts.default = 0
ARGF.each_line do |line|
if line =~ %r{GET /ongoing/When/\d\d\dx/(\d\d\d\d/\d\d/\d\d/[^ .]+) }
counts[$1] += 1
end
end
keys_by_count = counts.keys.sort { |a, b| counts[b] <=> counts[a] }
keys_by_count[0 .. 9].each do |key|
puts "#{counts[key]}: #{key}"
end

Bray's original idea was to check if Erlang is good option for this problem on multi-core platforms.

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