When comparing Scala vs Pyret, the Slant community recommends Scala for most people. In the question“What is the best programming language to learn first?” Scala is ranked 27th while Pyret is ranked 50th. The most important reason people chose Scala is:
The immutable values make it perfect for working with concurrency
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Immutable values
The immutable values make it perfect for working with concurrency
Pro Multiparadigm
Scala supports both Functional and Object Oriented styles of programming. Beginners can learn both paradigms without having to learn a new language, and experts can switch between the two according to what best suits their needs at the time.
Pro Type inference
Scala offers type inference, which, while giving the same safety as Java's type system, allows programmers to focus on the code itself, rather than on updating type annotations.
Pro Compiles to JVM bytecode
Aside from Java itself, Scala is by far the most popular of the many JVM languages. If you're developing for Android, or a similar JVM-only platform, or otherwise need out-of-the-box cross-platform compatibility, but the performance of a compiled language, Scala is the way to go.
Pro Very good online courses
On coursera you can find great introduction to Scala by Martin Odersky.
Pro Type inference leads to a simpler syntax
Pro Expressive functional programming abstraction for reusable and safe code
Pro Online IDE
You can use the development environment without installation in your browser and share your programs via the Google Drive integration.
Pro Designed for education
A primary goal of Pyret is to be an excellent choice for a first programming language. This heavily influences the development of the language. For example: if it's felt that some aspect of the language could be made better for the language's users, The development team won't hesitate about implementing breaking (non backwards compatible) changes into Pyret for the greater good of the language. This makes Pyret an impressively "wart free" programming language.
Cons
Con Can be intimidating for beginners
Scala is an industrial language. It brings functional programming to the JVM, but not with a "start small and grow the language" perspective, but rather a very powerful language for professional programmers.
Con Way too complex for beginners
Even for seasoned programmers it's a difficult language.
Con Static type system inherits cruft from Java
The type system is too complicated yet still less powerful than Haskell's.
Con Missing IDE features
For example: content assist, go to declaration, etc.