JEG2

fn increment(numbers: &Vec<int>) -> Vec<int> {
    numbers.iter().map(|n| n + 1).collect()
}

fn main() {
    let before = vec![1i, 2, 3];
    let after  = increment(&before);
    println!("{}", after);
}

JEG2

// I'm trying to make sure I have my head around "lifetimes"
// after a few readings of the guide:
// http://doc.rust-lang.org/guide-lifetimes.html.  The following is
// a simple example of what I think I now know that I'll try to explain
// in this comment.
//
// Because the letters are "borrowed references," (Do I have my terms right?)
// they could potentially be freed before the Lists struct that contains them.
// Since this possibility exists, Rust requires the explicit lifetime 'a which
// indicates that the lifetime of a created Lists instance is tied to whatever

JEG2

use std::fmt;
use std::os;

struct Stack {
    numbers: Vec<f64>
}
impl Stack {
    fn new() -> Stack {
        Stack{numbers: vec![]}
    }

JEG2

headers = nil
File.foreach(path) do |line|
  fields = line.split(“|”)
  if headers
    row = headers.zip(fields)
    # …
  else
    headers = fields
  end
end

JEG2

I have a problem that pretty much boils down to this:

a = [1, 2, 3]
b = [1.1, 2.2, 3.3]

# BEGIN GROSS SOLUTION:  avert your eyes!
results = [ ]
a.each do |i|
 b.each do |j|

JEG2

~/Desktop [ruby 2.0.0p247]$ cat dont_close_my_logger.rb
require "logger"

log    = ARGV.shift or abort "USAGE:  #{$PROGRAM_NAME} LOG"
logger = Logger.new(log)

threads  = [ ]
threads << Thread.new do
  logger.info "Thread one started.  Sleeping a bit to make sure thread two is going..."
  sleep 1

JEG2

class RequiredArgument
  def initialize(one, keyword: false)
    p [one, keyword]
  end
end

RequiredArgument.new(Hash.new)

# ruby 2.0.0p195 (2013-05-14 revision 40734) [x86_64-darwin12.3.0]
# bug.rb:2:in `initialize': wrong number of arguments (0 for 1) (ArgumentError)

JEG2

(set-face-attribute 'window-number-face nil :background "#2a2a2a")
(set-face-attribute 'window-number-face nil :foreground "red")

JEG2

I've been in multiple discussions lately about the problems with subclassing Ruby's base types.

The main problem is that Ruby sometimes takes shortcuts with the base types, for performance reasons. This can cause them to behave odd. For example, have a look at this subclass:

class MyString < String
  def initialize(*)
    super
    puts "Building MyString:  #{inspect}"
  end

JEG2

How Should We Use Struct?

The Choice

It's common in Ruby to see some code setup a Struct like this:

class Specialized < Struct.new(:whatever)
  # ... define custom methods here...
end