arpitchauhan

Monads

Understanding Monads

A concise definition from Wikipedia:

In functional programming, a monad is a design pattern that defines how functions, operations, inputs, and outputs can be used together to build generic types, with the following organization:

a. Define a data type, and how values of that data type are combined. b. Create functions that use the data type, and compose them together into operations, following the rules defined in the first step.

arpitchauhan

require './server'

run Sinatra::Application

# To flush output immediately
$stdout.sync = true

arpitchauhan

require 'sinatra'
require_relative 'basic_auth'

BasicAuth.enable_if_possible

arpitchauhan

class BasicAuth
  class << self
    def enable_if_possible
      return unless on?
  
      Sinatra::Application.use(Rack::Auth::Basic) do |username, password|
        valid_credentials?(username, password)
      end
    end
    

arpitchauhan

# server.rb

require 'sinatra'

arpitchauhan

source "https://rubygems.org"

ruby '2.5.1'
gem 'sinatra', '~> 2.0'

arpitchauhan

source "https://rubygems.org"

ruby '2.5.1'
gem 'sinatra', '~> 2.0'

arpitchauhan

Keybase proof

I hereby claim:

• I am arpitchauhan on github.
• I am arpitchauhan (https://keybase.io/arpitchauhan) on keybase.
• I have a public key whose fingerprint is 9ED4 1E1F FA8F 750C 11EE 6B15 A359 EE80 337B 31E3

To claim this, I am signing this object:

arpitchauhan

@movies = Movie.where("rating IN :ratings;" , {:ratings => params.has_key?(:ratings) ? params[:ratings].keys : @all_ratings})

The error page: 
ActiveRecord::StatementInvalid in Movies#index 
SQLite3::SQLException: near ",": syntax error: SELECT "movies".* FROM "movies"  WHERE (rating IN 'G','PG','PG-13','R','NC-17')

Full Trace:

sqlite3 (1.3.5) lib/sqlite3/database.rb:91:in `initialize'
sqlite3 (1.3.5) lib/sqlite3/database.rb:91:in `new'