Clean up the read and write operations

maps no longer need to be serializable. This allows for both a serializable form and a non-serializable form.

coordinates/src/hex_map.rs

@@ -10,7 +10,7 @@ Luminescent Dreams Tools is distributed in the hope that it will be useful, but
 You should have received a copy of the GNU General Public License along with Luminescent Dreams Tools. If not, see <https://www.gnu.org/licenses/>.
 */
 
-use crate::hex::AxialAddr;
+use crate::{hex::AxialAddr, Error};
 use nom::{
     bytes::complete::tag,
     character::complete::alphanumeric1,
@@ -29,10 +29,7 @@ pub struct Map<A> {
     cells: HashMap<AxialAddr, A>,
 }
 
-impl<A: Default + From<String> + Clone> Map<A>
-where
-    String: From<A>,
-{
+impl<A: Default + Clone> Map<A> {
     pub fn new_hexagonal(radius: usize) -> Map<A> {
         let cells = vec![(AxialAddr::origin(), Default::default())]
             .into_iter()
@@ -56,15 +53,22 @@ where
     pub fn get(&self, addr: &AxialAddr) -> Option<&A> {
         self.cells.get(addr)
     }
+}
 
-    // pub fn from_file(path: PathBuf) -> Map<A> {}
+pub fn read_file<A: Default + From<String>>(path: PathBuf) -> Result<Map<A>, Error> {
+    let data = std::fs::read_to_string(path)?;
+    Ok(parse_data(data.lines()))
+}
 
-    pub fn to_file(&self, path: PathBuf) -> () {}
+pub fn write_file<A: Clone>(path: PathBuf, map: Map<A>) -> Result<(), Error>
+where
+    String: From<A>,
+{
+    std::fs::write(path, write_data(map).join("\n")).map_err(Error::from)
+}
 
-    pub fn from_data(data: Vec<String>) -> Map<A> {
-        fn parse_line<A: From<String>>(
-            input: &str,
-        ) -> Result<(AxialAddr, A), nom::error::Error<&str>> {
+fn parse_data<'a, A: Default + From<String>>(data: impl Iterator<Item = &'a str> + 'a) -> Map<A> {
+    fn parse_line<A: From<String>>(input: &str) -> Result<(AxialAddr, A), nom::error::Error<&str>> {
         fn parse<A: From<String>>(input: &str) -> IResult<&str, (AxialAddr, A)> {
             let (input, addr) = parse_address(input)?;
             let (input, value) = cell_value::<A>(input)?;
@@ -75,21 +79,20 @@ where
     }
 
     let cells = data
-            .into_iter()
         .map(|line| parse_line::<A>(&line).unwrap())
         .collect::<Vec<(AxialAddr, A)>>();
     let cells = cells.into_iter().collect::<HashMap<AxialAddr, A>>();
     Map { cells }
-    }
+}
 
-    pub fn to_data(&self) -> Vec<String> {
-        self.cells
+fn write_data<A: Clone>(map: Map<A>) -> Vec<String>
+where
+    String: From<A>,
+{
+    map.cells
         .iter()
-            .map(|(addr, val)| {
-                format!("[{}, {}] {}", addr.q(), addr.r(), String::from(val.clone()))
-            })
+        .map(|(addr, val)| format!("[{}, {}] {}", addr.q(), addr.r(), String::from(val.clone())))
         .collect()
-    }
 }
 
 fn parse_address(input: &str) -> IResult<&str, AxialAddr> {
@@ -163,7 +166,7 @@ mod test {
         expected.insert("[0, -1] .".to_owned());
         expected.insert("[1, -1] .".to_owned());
 
-        let map_rows = map.to_data();
+        let map_rows = write_data(map);
         assert_eq!(map_rows.len(), expected.len());
         map_rows
             .iter()
@@ -182,12 +185,7 @@ mod test {
 [-1, 0] .
 [0, -1] .
 [1, -1] .";
-        let map: Map<MapVal> = Map::from_data(
-            map_data
-                .lines()
-                .map(|l| l.to_owned())
-                .collect::<Vec<String>>(),
-        );
+        let map: Map<MapVal> = parse_data(map_data.lines());
         assert_eq!(map.get(&AxialAddr::new(0, 0)), Some(&MapVal('L')));
         assert_eq!(map.get(&AxialAddr::new(1, 0)), Some(&MapVal('A')));
         assert_eq!(map.get(&AxialAddr::new(0, 1)), Some(&MapVal('.')));

coordinates/src/lib.rs

@@ -17,7 +17,13 @@ pub enum Error {
     IO(std::io::Error),
 }
 
+impl From<std::io::Error> for Error {
+    fn from(err: std::io::Error) -> Self {
+        Self::IO(err)
+    }
+}
+
 mod hex;
-mod hex_map;
+pub mod hex_map;
 
 pub use hex::AxialAddr;