Glossary

WSL

Windows Subsystem Linux - a way to run Linux on your Windows 10 computer.

WIMP

Windows Icons Menus Pointers

REPL

• read
• evaluate
• print
• loop

Persistence

State preserved when program quits and restarts.

Recursion

A recursive algorithm must:

1. Have a base case; an escape clause from the function
2. Change its state and move toward base case
3. Call itself recursively

Algorithm

An algorithm is a step by step list of instructions to solve a problem. Basic instructions:

• input
• output
• math and logic
• conditional execution
• repetition

Resource

A URN is similar to a person’s name, while a URL is like a street address. The URN defines something’s identity, while the URL provides a location. Essentially, “what” vs. “where”. A URN has to be of this form ::= "urn:" ":" where is the Namespace Identifier, and is the Namespace Specific String.

    A URL is a URI that:
    1) identifies a resource
    2) provides the means of locating the resource by describing the way to access it
    A URL is a URI
    A URI is not necessarily a URL

Constant Lookup Operator

The double colon :: in Ruby is the constant lookup operator. It’s used to scope any constant in a module.

module TaxRate
  BASE = 0.75

  class Calculated
    def max
      1.125
    end
  end
end
puts TaxRate::BASE
puts TaxRate::Calculated.new.max