The Blog

We have just fixed last regressions existing in generics branch and decided to move it into the main development branch. So it happened, generics are now supported on trunk.

A short notes about current status:

• Generic parameters are not visible in nested types, but they are visible in static members of current class #388.
• Generic specifier (the ugly def x = NotInferredClass .[string, int] (); syntax) works in most cases (methods and constructors), I guess it could have some problems in more complex cases (malekith knows the details) #474.
• We do not report errors for incorrect use of special constraints #386.
• We are aware of the error situation, which can arise from a very sick self tail call #478.

Other problems with generics should be reported as bugs - in general we would like to support all scenarios you could use in C# and much more (especially in case of type inference).

Short list of features:

• All built-in data-structures are now using generics (functional objects, tuples, lists).
• Most collections from Nemerle.Collections are now subtypes of .NET equivalents, but adding some new methods like Iter and Map for easier usage with functional objects. They also provide ToString override, which prints out their contents.
• All ugly bugs with arrays vs generics simulation has been fixed and forgotten.

• Type inference is very powerful in guessing the types of generic structures, if it can't it use object by default (you can use generic specifier or in some cases type enforcement to specify exact type parameters).

  Stuff like below works perfectly, is typesafe and require not casts.

  using System.Collections.Generic; def dict = Dictionary (); dict.Add (1, "travel"); dict.Add (2, "time"); assert (dict [1] == "travel");
• Nemerle collections can be used from C# without problems (we generate types, which are in the same format as C# compiler use).
• After a few patches for mono from malekith, the performance is almost the same as the compiler version without generics.

The bad news is that we were unable to get compiler working on MS.NET 2.0 (neither Beta 2 nor July CTP). There are numerous bugs, which we regularly report and sometimes manage to workaround. Currently building Nemerle.dll causes various exception stack traces in runtime, but when we copy it from boot/ then rest of the compiler builds fine. So you won't be able to use trunk with MS.NET until (hopefully) the next public release (I guess in September). Also with mono, you will need to use svn version (AFAIK the 1.1.9 release is not going out very soon, but probably it is a matter of month). Sorry for inconvenience.

For anybody, who is unable to run trunk version we have branched out the non-generic version into

you can also stay with trunk revision 5546