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Sam Roberts wrote:
When I require 'blah' it doesn't matter to me how much of the functionality is implemented in lua, and how much in C, though I do care what apis I get. Both are trivially implementable in terms of each other:
Exporting the two simple C functions is the more primitive interface, compared to exporting a table/userdatum with a metatable and two metamethods.
Also, note that setenv()/getenv() doesn't allow you to iterate the environment, at least one more function is required if the procedural/non-table API approach is taken.
The __index/__newindex interface will not necessarily allow iteration either. The reason for the separate os.environ() function is to provide a copy of the current environment to allow for easy modification of it before passing the modified copy to os.spawn(). This is for the relative frequent case where one would like to modify the environment of a spawned (child) process without modifying the current environment.
glob allows patterns matching files in more than one directory, the dir iterator+pattern match you show doesn't, though with a bit of recursion its possible, of course, even glob(3) is implemented with opendir(), its just nice not to have to recode glob() yourself from basic building blocks, in lua or in C.
This is my point exactly. The directory iterator interface is the more primitive interface. I guess one of the goals I have in mind is to reduce the amount of platform-dependent C, preferring instead to write as much of the code as possible in Lua, which can be shared among all the API implementations.
glob(3) can be implemented on non-UNIX systems as long as they actually have a file system. Its just some wildcard matching.
It's difficult to imagine what "/*.c" would do on a Windows system. Not all systems even use a slash as a directory separator (although I understand that most Windows APIs accept it in addition to backslash, even if the command line utilities do not). My point here is also even providing a function with the name "glob" would imply that it provides POSIX semantics when in fact it isn't possible to fully do so on non-POSIX systems.
I definitely think that glob() would be a valuable addition to any Lua POSIX binding. But the "ex" API does not aim to be a POSIX binding.
-Mark