update build subcmd to accept paths

[shakfu]

Only __main__.py is modified in this PR.

Basically it adds the following features:

• extensions can now be specified as <path> in addition to <name>=<path>
• make adding extensions required
• can change default prefix of <path> built extensions
• more validation checks

usage: pydust build [-h] [-z ZIG_EXE] [-b BUILD_ZIG] [-m] [-a]
                         [-p PREFIX]
                         extensions [extensions ...]

positional arguments:
  extensions            space separated list of extension '<path>' or
                        '<name>=<path>' entries

options:
  -h, --help            show this help message and exit
  -z ZIG_EXE, --zig-exe ZIG_EXE
                        zig executable path (default: None)
  -b BUILD_ZIG, --build-zig BUILD_ZIG
                        build.zig file (default: build.zig)
  -m, --self-managed    self-managed mode (default: False)
  -a, --limited-api     use limited python c-api (default: True)
  -p PREFIX, --prefix PREFIX
                        prefix of built extension (default: )

So basically the following is enabled:

python -m pydust build 'fib/hello.zig' 'fib._fib=fib/fib.zig' 

In the above case, fib/hello.zig is mapped to the name fib.hello
if --prefix=_ then it is mapped to the name fib._hello

[robert3005]

I think we can simplify the path munging with pathlib. For example it's simpler to get filename https://docs.python.org/3/library/pathlib.html#pathlib.PurePath.stem

[shakfu]

I think we can simplify the path munging with pathlib. For example it's simpler to get filename https://docs.python.org/3/library/pathlib.html#pathlib.PurePath.stem

Agreed.

[shakfu]

@robert3005

Thanks!