update readme, add intentions

Author: bjornregnell

README.md

@@ -10,13 +10,14 @@ This is a library with Scala utilities for Computer Science teaching. The librar
 
 This repo in used in this course *(in Swedish)*: http://cs.lth.se/pgk with course material published as free open source here: https://github.com/lunduniversity/introprog
 
-## How to use this library
+
+## How to use introprog-scalalib
 ### Using sbt
 
 If you have the [Scala Build Tool](https://www.scala-sbt.org/download.html) then you can put this text in a file called `build.sbt`
 ```
 scalaVersion := "2.12.6"
-libraryDependencies += "se.lth.cs" %% "introprog" % "0.1.5"
+libraryDependencies += "se.lth.cs" %% "introprog" % "1.0.0"
 ```
 
 When you run `sbt` in terminal the `introprog` package is automatically downloaded and made available on your classpath.
@@ -28,27 +29,47 @@ scala> val w = new introprog.PixelWindow()
 scala> w.fill(100,100,100,100,java.awt.Color.red)
 ```
 
-#### Manual download
+### Manual download
 
 Download the latest jar-file from here: https://github.com/lunduniversity/introprog-scalalib/releases
 
 Put the jar-file on your classpath when you run the Scala REPL, for example:
 ```
-> scala -cp introprog_2.12-0.1.5.jar
+> scala -cp introprog_2.12-1.0.0.jar
 scala> val w = new introprog.PixelWindow()
 scala> w.fill(100,100,100,100,java.awt.Color.red)
 scala>
 ```
 Put the jar-file on your classpath when you run your Scala app, for example:
 ```
-> scala -cp "introprog_2.12-0.1.5.jar:." Main
+> scala -cp "introprog_2.12-1.0.0.jar:." Main
 ```
 If on Windows cmd/powershell use `;` instead of `:` before the period.
 
-## How to build this library
+## How to build introprog-scalalib
 With [`sbt`](https://www.scala-sbt.org/download.html) and [`git`](https://git-scm.com/downloads) on your path type in terminal:
 ```
 > git clone git@github.com:lunduniversity/introprog-scalalib.git
 > cd introprog-scalalib
 > sbt package
 ```
+
+## Intentions and philosophy behind introprog-scalalib
+
+This repo includes utilities to empower learners to advance from basic to intermediate levels of computer science by providing easy-to-use constructs for creating simple desktop apps in terminal and using simple 2D graphics. The utilities are implemented and exposed through an api that follows these guidelines:
+
+* Use as simple constructs as possible.
+* Follow Scala idioms with a pragmatic mix of imperative, functional and object-oriented programming.
+* Don't use advanced functional programming concepts and magical implicit.
+* Prefer a clean api with single-responsibility functions in simple modules.
+* Prefer immutability over mutable state, `Vector` for sequences and case classes for data.
+* Hide/avoid threading and complicated concurrency.
+* Inspiration:
+  - [Talk by Martin Odersky: Scala the Simple Parts](https://www.youtube.com/watch?v=ecekSCX3B4Q) [Slides here](https://www.slideshare.net/Odersky/scala-the-simple-parts)
+  - [Principle of least power](http://www.lihaoyi.com/post/StrategicScalaStylePrincipleofLeastPower.html)
+
+Areas currently in scope of this library:
+
+* Simple 2D graphics.
+* Simple IO.
+* Simple, modal GUI dialogs.