I've been fiddling some more with C# code completion in emacs. I wrote a csde-shell.el that is the CSDE equivalent to JDE's beanshell.el . It runs as an inferior shell in emacs. The csde code-completion logic calls out to this shell to inquire about types by name. The shell then returns type information as lisp s-expressions, which can then be parsed and manipulated by csde-complete.el . Actually, the shell is nothing more than Powershell, with a particular assembly of mine loaded into it. The assembly exposes a couple static methods that return information about .NET types.

For example, if invoke this method within PowerShell:

[Ionic.Csde.Utilities]::GetTypeInfo("System.IO.DriveInfo","mscorlib, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089");

Then I get back something like this:

(list "System.IO.DriveInfo" 'type
             (list "Name" 'property "System.String" (cons 'typemodifiers (list "readonly" "public" )))
             (list "DriveType" 'property "System.IO.DriveType" (cons 'typemodifiers (list "readonly" "public" )))
             (list "DriveFormat" 'property "System.String" (cons 'typemodifiers (list "readonly" "public" )))
             (list "IsReady" 'property "System.Boolean" (cons 'typemodifiers (list "readonly" "public" )))
             (list "AvailableFreeSpace" 'property "System.Int64" (cons 'typemodifiers (list "readonly" "public" )))
             (list "TotalFreeSpace" 'property "System.Int64" (cons 'typemodifiers (list "readonly" "public" )))
             (list "TotalSize" 'property "System.Int64" (cons 'typemodifiers (list "readonly" "public" )))
             (list "RootDirectory" 'property "System.IO.DirectoryInfo" (cons 'typemodifiers (list "readonly" "public" )))
             (list "VolumeLabel" 'property "System.String" (cons 'typemodifiers (list "public" ))))
             (list "Equals" 'function "System.Boolean" (list "System.Object" )
                   (cons 'typemodifiers (list "public" )))
             (list "GetDrives" 'function "System.IO.DriveInfo[]" nil (cons 'typemodifiers (list "public" "static" )))
             (list "GetHashCode" 'function "System.Int32" nil (cons 'typemodifiers (list "public" )))
             (list "GetType" 'function "System.Type" nil (cons 'typemodifiers (list "public" )))
             (list "ToString" 'function "System.String" nil (cons 'typemodifiers (list "public" )))))

This is basically the same way JDEE works. It wasn't too difficult to set up the shell, because I already had a shell (Powershell). The trickiest part was formatting and parsing the s-expressions, on both the C# side and the elisp side.

With this, if you install into your emacs CSDE (remember CSDE is abandonware, stuck at version 0.1 since 2002), and then try a csde-complete-at-point, you will get context-sensitive code completion. Yow! The first time I saw it, I had to rub my eyes!   Yes, I said C# code completion in emacs. And this is not dabbrev. 

Ok, settle down.  This is really just a proof-of-concept at this point. There are tons of limitations, just oodles of them. The code completion is not very robust. It does not do Constructors, or public fields. It is not savvy to public/private/internal etc modifiers. It does not do parameter lists on methods - so once you select a method you have to key in all the parameters with no assistance. (Really in its current state it is nothing more than a smart property and method browser.)  The C# parser in Semantic apparently does not know about the var keyword (anonymous types) introduced in C# 3.0. So if you use var, then you don't get code completion. It only works, for now, on the classes in the .NET Framework base class library. It would have to be generalized to support other class libraries. Also, to be usable, all the pieces would have to be packaged together - CSDE, the CEDET and Semantic pieces, the Powershell piece. [ Update: I've attached to this post the elisp for csde  and the C# code for the CsdeShell.  But that is partial, not enough to get you started. more later on other posts. ]  

Like I said, tons of limitations. But it is a start. Yinz guys should ring me up if you have an interest in developing this further. Or, better, vote if you want me to make this a codeplex project, sort of CSDE-limited redux. (Remember the goal here was just code completion, much more limited that the broader goals of CSDE.)