Foreword to the First Edition

Martin Odersky made a huge impact on the Java world with his design of the Pizza language. Although Pizza itself never became popular, it demonstrated that object-oriented and functional language features, when combined with skill and taste, form a natural and powerful combination. Pizza's design became the basis for generics in Java, and Martin's GJ (Generic Java) compiler was Sun Microsystem's standard compiler starting in 1.3 (though with generics disabled). I had the pleasure of maintaining this compiler for a number of years, so I can report from first-hand experience that Martin's skill in language design extends to language implementation.

Since that time, we at Sun tried to simplify program development by extending the language with piecemeal solutions to particular problems, like the for-each loop, enums, and autoboxing. Meanwhile, Martin continued his work on more powerful orthogonal language primitives that allow programmers to provide solutions in libraries.

Lately, there has been a backlash against statically typed languages. Experience with Java has shown that programming in a static language results in an abundance of boilerplate. The common wisdom is that one must abandon static typing to eliminate the boilerplate, and there is a rising interest in dynamic languages such as Python, Ruby, and Groovy. This common wisdom is debunked by the existence of Martin's latest brainchild, Scala.

Scala is a tastefully typed language: it is statically typed, but explicit types appear in just the right places. Scala takes powerful features from object-oriented and functional languages, and combines them with a few novel ideas in a beautifully coherent whole. The syntax is so lightweight, and its primitives so expressive, that APIs can be used with virtually no syntactic overhead at all. Examples can be found in standard libraries such as parser combinators and actors. In this sense Scala supports embedded domain-specific languages.

Will Scala be the next great language? Only time will tell. Martin Odersky's team certainly has the taste and skill for the job. One thing is sure: Scala sets a new standard against which future languages will be measured.

Neal Gafter
San Jose, California
September 3, 2008