Reading up on Subversion, I came across some references [L1 ] to the Apache Portable Runtime Library, which is described as follows:
- APR is Apache's portability library, originally carved out of its server code as an attempt to separate the OS-specific bits from the OS-independent portions of the code. The result was a library that provides a generic API for performing operations that differ mildly—or wildly—from OS to OS.
My main reaction to this was "So what? We've got one of these too — perhaps even more portable" (cf. On What Platforms Does Tcl Run), but of course "XXX Portable Runtime Library" sounds a bit snazzier than libtcl.so...
Therefore I think it would be a good idea to collect some information about using Tcl as a C library, but since I haven't had much practical experience in the matter, I'm hoping others can lend a hand in fleshing it out, — Lars H, 2007-11-11.
Features available from the Tcl C library include...
Low level features (meaning roughly that if you really need to, it would probably be possible to extract the implementation of these from the rest of the library)
- Keys can be strings, integers, or pointers. Entries are pointers. Custom hashing functions can, but doesn't have to, be supplied.
- Efficient C-style strings whose memory allocation grow as needed — no more buffer overflows!
- A Unicode-aware and fast RE engine.
- libtommath (as of 8.5)
- Arbitrary-precision arithmetic
Medium level features (meaning roughly you can use them without worrying about the big picture)
- Tcl_Objs, lists, and dicts
- Nestable generic data containers.
- Convert between Unicode and other character encodings.
- Event loop
- [write something about it]
- equivalent to sleep(), but more accurate (time is expressed in ms, not in seconds)
- Many of the thread APIs are thoroughly inconsistent across platforms, but Tcl hides that.
High level features
- Attached to files, pipes, sockets, serial ports, or whatsnot. Stackable. [Probably have many more features]
- Date and time format handling.
- Native or VFS, it's all the same. Support for varying file path syntaxes.
- Tcl interpreter
- You can have none, one, or several; create or destroy dynamically.
[List incomplete. Categorization may be wrong.]
[Would be nice to point out areas where Tcl hides inconsistent behaviour on different platforms. Threads, perhaps?]
See also Tk Portable Runtime Library.