stak-process-context 0.12.18

Process context for Stak Scheme
Documentation 
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use crate::ProcessContext;
use core::{ffi::CStr, slice};

/// A process context based on libc.
#[derive(Debug)]
pub struct LibcProcessContext {
    arguments: &'static [*const i8],
}

impl LibcProcessContext {
    /// Creates a process context.
    ///
    /// # Safety
    ///
    /// The `argc` and `argv` arguments should be the ones passed down as
    /// arguments to the `main` function in C.
    pub const unsafe fn new(argc: isize, argv: *const *const i8) -> Self {
        Self {
            // SAFETY: Operating systems guarantee the length of `argv` to be `argc`.
            arguments: unsafe { slice::from_raw_parts(argv, argc as _) },
        }
    }
}

impl ProcessContext for LibcProcessContext {
    fn command_line_rev(&self) -> impl IntoIterator<Item = &str> {
        self.arguments.iter().rev().map(|&argument| {
            // SAFETY: Operating systems guarantee elements in `argv` to be C strings.
            unsafe { CStr::from_ptr(argument as _) }.to_str().unwrap()
        })
    }

    fn environment_variables(&self) -> impl IntoIterator<Item = (&str, &str)> {
        []
    }
}