davegurnell

import scala.language.experimental.macros
import scala.reflect.macros.blackbox.Context

object PrintForMacros {
  def printFor[A](expr: A): A =
    macro PrintForMacros.printForMacro[A]
}

class PrintForMacros(val c: Context) {
  import c.universe._

davegurnell

macro di {
  case {
    _(function ($args (,) ...) {
      $body...
    })
  } => {
    letstx $names... = _.map(
      #{ $args... },
      function(ident) {
        return makeValue(ident.token.value, ident);

davegurnell

trait DatabaseLayer {
  def dependency: Int
}

trait ConcreteDatabaseLayer extends DatabaseLayer {
  def dependency: Int = 100
}

trait DatabaseResource1 {
  this: DatabaseLayer =>

davegurnell

Error Handling in Scala

Scala does not have checked exceptions like Java, so you can't do soemthing like this to force a programmer to deal with an exception:

public void stringToInt(String str) throws NumberFormatException {
  Integer.parseInt(str)
}

davegurnell

sealed trait PhpValue {
  def \(field: PhpValue): Seq[PhpValue] = Seq.empty[PhpValue]
  def \\(field: PhpValue): Seq[PhpValue] = Seq.empty[PhpValue]
}

sealed trait PhpArrayLike extends PhpValue {
  def fields: Map[PhpValue, PhpValue]

  override def \(field: PhpValue): Seq[PhpValue] =
    fields.toSeq.collect {

davegurnell

/* ===== NOTE =====
 *
 * This code sample is out-of-date!
 *
 * If you're looking for support for shapeless HLists in Slick queries, 
 * check out [Slickless](https://github.com/underscoreio/slickless).
 *
 * ================
 */
import slick.driver.MySQLDriver.simple._

davegurnell

#!/usr/bin/env bash

git checkout master
git branch -D nohistory

for branch in `git branch | cut -c2-`
do
  echo "========== $branch =========="
  git checkout $branch
  git branch -D nohistory

davegurnell

lazy val chat = project.in(file(".")).enablePlugins(PlayScala)

scalaVersion in chat := "2.11.4"

libraryDependencies in chat ++= Seq(
  jdbc,
  anorm,
  "org.postgresql"    %  "postgresql" % "9.3-1101-jdbc4",
  "org.webjars"       %  "bootstrap"  % "3.0.2",
  "org.scalatestplus" %% "play"       % "1.2.0"           % "test"

davegurnell

/*

Overview
--------

To run a query using anorm you need to do three things:

 1. Connect to the database (with or without a transaction)
 2. Create an instance of `anorm.SqlQuery` using the `SQL` string interpolator
 3. Call one of the methods on `SqlQuery` to actually run the query

davegurnell

def userId(username: String): Option[Int] =
  Some(1)

def mostRecentOrderId(userId: Int): Option[Int] =
  Some(2)

def orderCost(orderId: Int): Option[Int] =
  Some(3)

def mostRecentOrderCost(username: String): Option[Int] =