akahn

# Validations added in an instance hook:

model.after_validation_hook { model.errors.add("random_attribute", 'Unrecognized attribute') }

# Later:

> model.valid?
=> false
> model.errors
=> {"random_attribute"=>["Unrecognized attribute"]}

akahn

module Cellular where

import System.Random
import Data.List.Split
import Data.Maybe

isWall False = '.'
isWall True  = '#'

mapWithIndex :: (Enum a, Num a) => (a -> b -> c) -> [b] -> [c]

akahn

$ curl -XPOST http://localhost:9200/myindex/mytype -d '{"foo": ["bar"]}'
{"ok":true,"_index":"myindex","_type":"mytype","_id":"YYfPUL3TQLaL17zhXQ-ELw","_version":1}

$ curl -XPOST http://localhost:9200/myindex/mytype -d '{"foo": [{"foo": "bar"}]}'
{"error":"MapperParsingException[Failed to parse [foo]]; nested: ElasticSearchIllegalArgumentException[unknown property [foo]]; ","status":400}

$ curl -XDELETE http://localhost:9200/myindex/mytype
{"ok":true}

$ curl -XPOST http://localhost:9200/myindex/mytype -d '{"foo": [{"foo": "bar"}]}'

akahn

def case_wat
  case number = 1
  when number == 1
    'expected'
  else
    'wat'
  end
end

akahn

def find_value(key, hash)
  result = hash
  key.split('.').each do |segment|
    segment = segment.to_i if segment =~ /\d+/
    result = result[segment]
    return unless result
  end
  result
end

akahn

def save_and_open_page
  File.write('tmp/last_response.html', last_response.body)
  `open tmp/last_response.html`
end

akahn

>> connection = PGconn.new(...)
>> connection.exec('update foo set bar=true') # long running query
^C^C^C^C^C^C

# Can't cancel the query

>> connection.async_exec('update foo set bar=true') # long running query
^C
>>

akahn

#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

int main ()
{
  pid_t child_pid;

  child_pid = fork ();
  if (child_pid > 0) {

akahn

SELECT datname, procpid, usename, client_addr, current_query, (current_timestamp - query_start) AS duration
FROM pg_stat_activity
WHERE datname = 'your-database'
ORDER BY duration DESC;

akahn

class AdvancingTimeRange
  def initialize(time = '2009-03-01')
    @cursor = DateTime.parse(time)
  end

  def next(increment_by)
    range = @cursor..@cursor + increment_by
    @cursor = range.end
    range
  end