/// Fork into a process from a Verse
///
/// Figures out whether or not the given Verse is a couplet. If it is, fork
/// into a process, and pipe the contents of out `out` into STDIN. If not, then
/// simply fork into the process.
///
/// # Arguments
/// * `$verse: &Verse` - The verse to fork into
/// * `$out: &mut String` - If the $verse is a couplet, the contents of STDOUT from the last verse
#[macro_export]
macro_rules! task {
    ($verse:expr, $out:expr) => {
        if $verse.couplet {
            let mut child = Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .stdin(Stdio::piped())
                .spawn()?;

            let stdin = child.stdin.as_mut().ok_or(io::ErrorKind::BrokenPipe)?;
            stdin.write_all(&$out)?;
            $out.clear();

            child
        } else {
            Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .spawn()?
        }
    };
}

/// Fork into a process from a Verse, and capture STDOUT
///
/// Figures out whether or not the given Verse is a couplet. If it is, fork
/// into a process, and pipe the contents of out `out` into STDIN. If not, then
/// simply fork into the process. Additionally, this function will capture
/// STDOUT of the process specified by the Verse, and store it in `out`.
///
/// # Arguments
/// * `$verse: &Verse` - The verse to fork into
/// * `$out: &mut String` - If the $verse is a couplet, the contents of STDOUT from the last verse
#[macro_export]
macro_rules! ctask {
    ($verse:expr, $out:expr) => {
        if $verse.couplet {
            let mut child = Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .stdin(Stdio::piped())
                .stdout(Stdio::piped())
                .spawn()?;

            let stdin = child.stdin.as_mut().ok_or(io::ErrorKind::BrokenPipe)?;
            stdin.write_all(&$out)?;
            $out.clear();

            child
        } else {
            Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .stdout(Stdio::piped())
                .spawn()?
        }
    };
}

/// Fork into a background process from a Verse
///
/// Figures out whether or not the given Verse is a couplet. If it is, fork
/// into a backgournd process, and pipe the contents of out `out` into STDIN.
/// If not, then simply fork into the background process.
///
/// # Arguments
/// * `$verse: &Verse` - The verse to fork into
/// * `$out: &mut String` - If the $verse is a couplet, the contents of STDOUT from the last verse
#[macro_export]
macro_rules! btask {
    ($verse:expr, $out:expr) => {
        if $verse.couplet {
            let mut child = Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .stdin(Stdio::piped())
                .process_group(0)
                .spawn()?;

            let stdin = child.stdin.as_mut().ok_or(io::ErrorKind::BrokenPipe)?;
            stdin.write_all(&$out)?;
            $out.clear();

            child
        } else {
            Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .process_group(0)
                .spawn()?
        }
    };
}

/// Fork into a background process from a Verse, and capture STDOUT
///
/// Figures out whether or not the given Verse is a couplet. If it is, fork
/// into a backgournd process, and pipe the contents of out `out` into STDIN.
/// If not, then simply fork into the background process. This captures the
/// output of STDOUT, in order to redirect it to a file when the program
/// finishes running.
///
/// # Arguments
/// * `$verse: &Verse` - The verse to fork into
/// * `$out: &mut String` - If the $verse is a couplet, the contents of STDOUT from the last verse
#[macro_export]
macro_rules! iobtask {
    ($verse:expr, $out:expr) => {
        if $verse.couplet {
            let mut child = Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .stdin(Stdio::piped())
                .stdout(Stdio::piped())
                .process_group(0)
                .spawn()?;

            let stdin = child.stdin.as_mut().ok_or(io::ErrorKind::BrokenPipe)?;
            stdin.write_all(&$out)?;
            $out.clear();

            child
        } else {
            Command::new($verse.verb())
                .args($verse.clause().unwrap_or(vec![]))
                .stdout(Stdio::piped())
                .process_group(0)
                .spawn()?
        }
    };
}