language-design

Scala (at least on the JVM ) uses type erasure for Java compatibility. This feature is widely held to suck . Fixing this would be difficult on the JVM . In contrast to the JVM situation, .NET supports reified generics. Does Scala's .NET implementation use them? If not, could it, or else what issues would using reification cause? It's work in progress, carefully not to break Scala semantics between JVM and .NET. I asked this question back in 2011 on the scala-tools mailinglist and the answer is given by Miguel Garcia in which he outlines the big picture: Some quotes: (1) What the Scala.Net

Ok I must be overlooking something extremely simple but I am lost. Given this object val = -1; var foo = (Int32)(val); var bar = (Int64)(val); The cast to Int64 throws and InvalidCastException. I recognize this is related to some strangeness with boxing but I don't understand the reasoning. From what I understand val is boxed as Int32 on the first line. Then when I try to cast as something other than Int32 InvalidCastException is thrown. I suppose this means that I am trying to unbox val as Int64 when it is actually an Int32? Still seems strange. Couldn't the cast unbox the value and then try

There are many people who think that the concept of the special value null (as it is used in lanuages like C, Java, C#, Perl, Javascript, SQL etc.) is a bad idea. There are several questions about this on SO and P.SE, such as Best explanation for languages without null and Are null references really a bad thing? . However, I could not find any language that does without them. All the languages I'm familiar with have null , or something similar (e.g. "undefined" in Perl). I realize that proably every language needs some way to express "absence of a value". However, instead of having "null" or

I would like to create my own programming language. Maybe not exactly a programming language from scratch but maybe base it on another language. I've heard of Yacc. So, I installed Flex and Bison. But I do not understand how to make a compiler with it. I have made the Hello world project in it, but how would I make a compiler in it? Are there any easy ways of creating a small programming language, I have heard of translating a language as in taking, e.g., Write() and making the computer understand it as Print() . Is this be possible?. My take on this is that the simpler approach is not to mess

Why is the Haskell implementation so focused on linked lists? For example, I know Data.Sequence is more efficient with most of the list operations (except for the cons operation), and is used a lot; syntactically, though, it is "hardly supported". Haskell has put a lot of effort into functional abstractions, such as the Functor and the Foldable class, but their syntax is not compatible with that of the default list. If, in a project I want to optimize and replace my lists with sequences - or if I suddenly want support for infinite collections, and replace my sequences with lists - the