atomicscala/atomic-scala-examples

Examples from the book "Atomic Scala" 2nd Edition by Bruce Eckel & Dianne Marsh

atomic-scala-examples's Issues

Consider adding a chapter on SBT

Hi all,

Greatly enjoyed the book, but there's one thing I felt was missing. As a Python programmer, I'm very familiar with using pip and pypi to find whatever packages I need to extend my code, and it's the Python ecosystem that makes the language as powerful as it is. My very rough understanding is that sbt provides some similar functionality (as well as other build-tool items) and is a bit more standard for Scala than Maven is, and I think the book would be stronger if people knew where to look for useful Scala libraries and knew how use a build tool to link them. Would you consider adding a chapter on how to use SBT? I feel like you could extend the lesson where you downloaded the Apache Commons Math JAR to writing a build.sbt that downloads the package as a part of building the Scala project.

Anyway, just my suggestion.

Best,
Paul

Windows 10 + Typesafe Activator

Istvan Orban email

Hi,

Just bought the book and also downloaded the examples file.

I have jdk 1.8 on WIN 10 when I run the activator.bat I got the following error message.

ava HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=64M; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256M; support was removed in 8.0
Getting com.typesafe.activator activator-launcher 0.4.2 ...

:: problems summary ::
:::: WARNINGS
module not found: com.typesafe.activator#activator-launcher;0.4.2

    ==== activator-local: tried

      file:////d:/LearningScala//repository/com.typesafe.activator/activator-launcher/0.4.2/ivys/ivy.xml

    ==== Maven Central: tried

      http://repo1.maven.org/maven2/com/typesafe/activator/activator-launcher/0.4.2/activator-launcher-0.4.2.pom

    ==== typesafe-releases: tried

      http://typesafe.artifactoryonline.com/typesafe/releases/com/typesafe/activator/activator-launcher/0.4.2/activator-launcher-0.4.2.pom 

    ==== typesafe-ivy-releases: tried

      http://typesafe.artifactoryonline.com/typesafe/ivy-releases/com.typesafe.activator/activator-launcher/0.4.2/ivys/ivy.xml 

            ::::::::::::::::::::::::::::::::::::::::::::::

            ::          UNRESOLVED DEPENDENCIES         ::

            ::::::::::::::::::::::::::::::::::::::::::::::

            :: com.typesafe.activator#activator-launcher;0.4.2: not found

            ::::::::::::::::::::::::::::::::::::::::::::::

:: USE VERBOSE OR DEBUG MESSAGE LEVEL FOR MORE DETAILS
unresolved dependency: com.typesafe.activator#activator-launcher;0.4.2: not found
Error during sbt execution: Error retrieving required libraries
(see .sbt\boot\update.log for complete log)
Error: Could not retrieve activator-launcher 0.4.2

Any reason why this could be and where I should start looking ?

Thanks a lot!

Java 8 issue

Activator team wrote me:

The Atomic Scala template uses a Scala version that unfortunately does not support Java8.
See: http://stackoverflow.com/questions/24517761/scala-repl-throws-error

There are a couple of ways around this.

run the existing template with a Java version < 8 (e.g. 6 or 7).
keep Java8 as JVM runtime and instead change the Scala version in the template (change all 2.10.1 to 2.10.4 in the file build.sbt)

Area of a circle is pi*r^2

I realize the exercise is more with the practice of coding than any actual computational geometry, but thought I might as well point this out. In Shape_Inheritance.scala and Shape_TypeClass.scala, you're using the circumference formula for a circle, not the area formula (Pi * radius * radius).

Just a heads up.