Types of index scans
Indexes
Sequential Scan:
- Read every row in the table
- No reading of index. Reading from indexes is also expensive.
require 'delegate' | |
module ConcatHelper | |
def concat(*elements, separator) | |
elements.reject(&:blank?).join(separator) | |
end | |
def format(format_string, string) | |
format_string % string unless string.blank? | |
end |
class Obj | |
attr_reader :a | |
def initialize(a) | |
@a = a | |
end | |
def ==(other) | |
a == other.a | |
end |
import time | |
class ContextManager(): | |
def __init__(self, generator_method, args, kwargs): | |
self.generator_method = generator_method | |
self.args = args | |
self.kwargs = kwargs | |
def __enter__(self): |
defmodule FizzBuzz do | |
defmacro __using__(_) do | |
quote do | |
alias FizzBuzz.FunctionSignaturePatternMatching, as: FSPM | |
alias FizzBuzz.GuardClause | |
alias FizzBuzz.Case | |
alias FizzBuzz.Cond | |
alias FizzBuzz.If | |
import FizzBuzz.AnonymousFunction |
" How to process a set of files (includes escaping file name) and populate the arglist | |
" This example "copies" everything from quickfix to arglist | |
command! -nargs=0 -bar Qargs execute 'args' QuickfixFilenames() | |
function! QuickfixFilenames() | |
let buffer_numbers = {} | |
for quickfix_item in getqflist() | |
let buffer_numbers[quickfix_item['bufnr']] = bufname(quickfix_item['bufnr']) | |
endfor | |
return join(map(values(buffer_numbers), 'fnameescape(v:val)')) | |
endfunction |
# this was copied from https://carc.in/#/r/fg2 | |
# thanks to @waterlink from this issue thread https://github.com/crystal-lang/crystal/issues/1388 | |
module CrChainableMethods | |
module Pipe | |
macro pipe(ast) | |
{% uast = ast.stringify.gsub(/ >>/, ".pipe").id %} | |
{% pp uast %} | |
{% if uast.stringify != ast.stringify %} | |
pipe {{uast}} |
Open your project (if you're using WebPack, obviously)
npm install sinon --save-dev
You should now have Sinon in your node modules and listed in your package.json
file
In your tests, require Sinon: var sinon = require('sinon');
<!-- app/views/home/index.html.erb --> | |
<div data-twitter-app> | |
<div data-tweets> | |
</div> | |
</div> |
# spec/features/twitter_timeline_spec.rb | |
require 'feature_helper' | |
RSpec.feature 'twitter timeline' do | |
scenario 'a user views a twitter timeline' do | |
pending | |
visit root_path | |
within '[data-twitter-app]' do |