Add reexport command

brood/src/commands.rs

@@ -0,0 +1,5 @@
+mod ingest;
+mod reexport;
+
+pub use ingest::ingest;
+pub use reexport::reexport;

brood/src/commands/reexport.rs

@@ -0,0 +1,17 @@
+use std::fs::File;
+use std::io::{self, BufReader, BufWriter};
+use std::path::Path;
+
+use crate::data::AdjacencyList;
+
+pub fn reexport(from: &Path, to: &Path) -> io::Result<()> {
+    eprintln!(">> Import");
+    let from = BufReader::new(File::open(from)?);
+    let data = AdjacencyList::read(from)?;
+
+    eprintln!(">> Export");
+    let to = BufWriter::new(File::create(to)?);
+    data.write(to)?;
+
+    Ok(())
+}

brood/src/main.rs

@@ -11,6 +11,8 @@ use clap::Parser;
 enum Command {
     /// Read sift data on stdin and output brood data.
     Ingest,
+    /// Read and reexport brood data.
+    Reexport { to: PathBuf },
 }
 
 #[derive(Debug, Parser)]
@@ -24,5 +26,6 @@ fn main() -> io::Result<()> {
     let args = Args::parse();
     match args.command {
         Command::Ingest => commands::ingest(&args.datafile),
+        Command::Reexport { to } => commands::reexport(&args.datafile, &to),
     }
 }