Initial commit

1 files changed, 112 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..e6b1b78
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,112 @@
+mod encoded_string;
+mod error;
+mod main_result;
+
+use std::{
+	collections::HashSet,
+	env,
+	hash::Hash,
+	io::{self, BufRead, BufReader, BufWriter, Write, Seek, SeekFrom},
+	process::Command
+};
+
+use encoded_string::*;
+use error::*;
+use main_result::*;
+
+use {
+	itertools::Itertools,
+	tempfile::NamedTempFile
+};
+
+fn main() -> MainResult {
+	work().into()
+}
+
+fn work() -> Result<(), Error> {
+	let files = env::args().skip(1).collect::<Vec<String>>();
+	let dups = duplicate_elements(files.clone());
+	if !dups.is_empty() {
+		return Err(Error::DuplicateElems(dups));
+	}
+
+	let mut tmpfile = NamedTempFile::new()?;
+	let mut writer = BufWriter::new(&tmpfile);
+
+	files.iter().try_for_each(|f| encode_to_file(&mut writer, f))?;
+	writer.flush()?;
+	drop(writer);
+
+	let editor = env::var("EDITOR")
+		.ok()
+		.filter(|e| !e.is_empty())
+		.ok_or(Error::NoEditor)?;
+
+	Command::new(&editor)
+		.arg(tmpfile.path().as_os_str())
+		.spawn()
+		.map_err(|err| Error::SpawnFailed(editor, err))?
+		.wait()?;
+
+	tmpfile.seek(SeekFrom::Start(0))?;
+	let new_files = decode_from_file(&tmpfile)?;
+
+	assert_changes(
+		    files.iter().cloned().collect(),
+		new_files.iter().cloned().collect()
+	)?;
+	new_files.iter().for_each(|f| println!("{}", f));
+
+	Ok(())
+}
+
+fn assert_changes(old: Vec<String>, new: Vec<String>) -> Result<(), Error> {
+	if old.len() != new.len() {
+		return Err(Error::BadLengths);
+	}
+
+	let dups = duplicate_elements(new);
+	if !dups.is_empty() {
+		return Err(Error::DuplicateElems(dups));
+	}
+
+	Ok(())
+}
+
+fn duplicate_elements<T>(iter: T) -> Vec<T::Item>
+where
+	T: IntoIterator,
+	T::Item: Clone + Eq + Hash
+{
+	let mut uniq = HashSet::new();
+	iter
+		.into_iter()
+		.filter(|x| !uniq.insert(x.clone()))
+		.unique()
+		.collect::<Vec<_>>()
+}
+
+fn encode_to_file<W: Write>(f: &mut W, s: &str) -> io::Result<()> {
+	s.chars().try_for_each(|c| {
+		write!(f, "{}", match c {
+				'\\' => "\\\\",
+				'\n' => "\\n",
+				_ => return write!(f, "{}", c),
+			}
+		)
+	})?;
+	write!(f, "{}", '\n')
+}
+
+fn decode_from_file(tmpfile: &NamedTempFile) -> Result<Vec<String>, io::Error> {
+	BufReader::new(tmpfile)
+		.lines()
+		.map(|r| match r {
+			Ok(s) => {
+				let es = EncodedString { s: s.bytes() };
+				Ok(es.decode())
+			},
+			Err(_) => r
+		})
+		.collect::<Result<Vec<String>, _>>()
+}