cvogt

scala> :paste
  class :=[T,Q]
  trait Default_:={
    /** Ignore default */
    implicit def useProvided[Provided,Default] = new :=[Provided,Default]
  }
  object := extends Default_:={
    /** Infer type argument to default */
    implicit def useDefault[Default] = new :=[Default,Default]
  }

cvogt

import scala.slick.lifted.CanBeQueryCondition
// optionally filter on a column with a supplied predicate
case class MaybeFilter[X, Y](val query: scala.slick.lifted.Query[X, Y]) {
  def filter[T,R:CanBeQueryCondition](data: Option[T])(f: T => X => R) = {
    data.map(v => MaybeFilter(query.filter(f(v)))).getOrElse(this)
  }
}

// example use case
import java.sql.Date

cvogt

#!/bin/sh
cd "$(dirname "$0")"
touch .git/hooks/pre-commit
rm .git/hooks/pre-commit
ln -s ../../pre-commit-hook.sh .git/hooks/pre-commit

cvogt

// Please comment in case of typos or bugs
 
import scala.slick.driver.H2Driver._
val db = Database.for...(...)

case class Record( ... )
class Records(tag: Tag) extends Table[Record](tag,"RECORDS"){
  ...
  def * = ... <> (Record.tupled,Record.unapply)
  // place additional methods here which return values of type Column

cvogt

# Configuring DNS-over-TLS on macOS
# Worked on macOS 10.13.4
brew -v update
brew -v doctor
# Next two commands are optional
sudo chown -R $(whoami) $(brew --prefix)/*
echo 'export PATH="/usr/local/sbin:$PATH"' >> ~/.bash_profile
# Install DNS client
brew install knot-resolver
# Should be installed to something like: /usr/local/Cellar/knot-resolver/2.3.0/sbin/kresd

cvogt

#!/usr/bin/env python2.7
# https://gist.github.com/cvogt/1e46597e39bfe0e0aee8d5348123ca03
# based on https://gist.github.com/alexeygrigorev/a1bc540925054b71e1a7268e50ad55cd#file-vimeo-download-py
# also see https://github.com/eMBee/vimeo-download

import requests
import base64
import sys
from tqdm import tqdm

cvogt

Getting Started in Scala

This is my attempt to give Scala newcomers a quick-and-easy rundown to the prerequisite steps they need to a) try Scala, and b) get a standard project up and running on their machine. I'm not going to talk about the language at all; there are plenty of better resources a google search away. This is just focused on the prerequisite tooling and machine setup. I will not be assuming you have any background in JVM languages. So if you're coming from Python, Ruby, JavaScript, Haskell, or anywhere…  I hope to present the information you need without assuming anything.

Disclaimer It has been over a decade since I was new to Scala, and when I was new to Scala, I was coming from a Java and Ruby background. This has probably caused me to unknowingly make some assumptions. Please feel free to call me out in comments/tweets!

One assumption I'm knowingly making is that you're on a Unix-like platform. Sorry, Windows users.

Getting the JVM

cvogt

import scala.slick.lifted.{TableQuery => _}
import scala.slick.ast._
import scala.slick.driver._
import scala.language.implicitConversions
 
/** Extends QueryInvoker to allow overriding used SQL statement when executing a query */
trait OverridingInvoker extends JdbcDriver{
  // get the extended QueryInvoker into the .simple._ implicits
  override val Implicit: Implicits = new Implicits
  override val simple: Implicits with SimpleQL = new Implicits with SimpleQL

cvogt

case class Foo( bar: Bar )
case class Bar( bar: Baz )
case class Baz( bar: Booyah )
case class Booyah( i: Int, s: String )

object V1Serializers{
  implicit def FormatFoo[Foo] = ...
  implicit def FormatBar[Bar] = ...
  implicit def FormatBaz[Baz] = ...
  implicit def FormatBooyah[Booyah] = ...

cvogt

package com.pretend.myforklift

import com.liyaos.forklift.slick.{ SlickCodegen, SlickMigrationCommandLineTool, SlickMigrationCommands, SlickMigrationManager }

import scala.io.StdIn

trait MyMigrationCommands extends SlickMigrationCommands
  with MyMigrationFilesHandler {
  this: SlickMigrationManager with SlickCodegen =>