[catfish17]

>That said, C# solves this problem near perfectly.

Hadn't it already been solved in Java even better before? It doesn't look right to praise C# for resolving the problem when C# merely took that idea from Java. C# came up with the templates part though.

What C# didn't copy was the idea of turning every source file into a binary file. A library is just a zip archive of those .class binary files. What's the advantage for C# to not have .class files and to pack everything into a 'proprietary' library format? Why haven't they copied the zip-idea, too?

[unnouinceput]

Gentle reminder that architect of C# was snatched by Microsoft from Borland. Before that he was main guy at Borland for Pascal/Delphi. So I'm not so sure he simply copied from Java anything.

https://en.wikipedia.org/wiki/Anders_Hejlsberg

[pjmlp]

His first job at Microsoft was creating J++.

He was not snatched, he left Borland unhappy with its management and Microsoft was the obvious choice as next employer.

[higerordermap]

> Gentle reminder that architect of C# was snatched by Microsoft from Borland.

snatching wutt? They could have paid more to keep him.

Not a Microsoft fan either, but Borland managers have no right to complain :)

[ckok]

No duplication. There's a single file where every type reference or method reference exists once. Note that it's not a library file. The compiled dll or exe has no relationship to the original way it was stored in .cs file. Instead it's a set of tables which hold all types, all members.

[pjmlp]

Partial types.

[john_moscow]

The main reason is to have a library-scope name table and a bunch of global indexes. Can't beat that in terms of performance.

[thu2111]

Worth noting that Java has this too now, it's called the "jimage" format. However it's not used for redistribution of compiled artifacts, that's still JARs. Instead a jimage file is created when JARs are "jlinked" into a runtime image.

This requires modules and it's a new technique that post-dates Java 8, so not many Java shops use it yet. However Java 9+ comes optimised this way by default, that's what the 'modules' file is in the JDK lib directory. Class files have their strings extracted and placed into a single string table are compressed, and their offsets then placed into a "perfect hash table" that's guaranteed to satisfy lookups in O(1) or O(2) time.

[projektfu]

You can look back at least as far as Ada83 to find a specification for a library manager as part of the system, where precompiled modules are stored in a format that lends itself to faster compilation.

[fanf2]

However the Ada library manager has a reputation for being complicated, slow, and fragile. Gnat was able to compile Ada much faster by using a C-style compilation model instead! https://dwheeler.com/essays/make-it-simple-dewar.html

[projektfu]

Oh, definitely, but just because the implementation sucks doesn't mean that the idea isn't there.

Modula-3 was also pretty slow compiling, but it also compiled interfaces so that it could refer to them. Unfortunately, the underlying objects could change during a compilation because of partial revelation, so parts of the system would have to be recompiled when the builder found those cases. I'm sure Modula-2 could have been faster in that regard, not having the opportunity for a type to be elaborated more in later compilation units.