1 files changed, 34 insertions, 25 deletions

diff --git a/apps/cassiopeia/src/format/mod.rs b/apps/cassiopeia/src/format/mod.rs
index 89f3a6ccb466..65c2264d6829 100644
--- a/apps/cassiopeia/src/format/mod.rs
+++ b/apps/cassiopeia/src/format/mod.rs
@@ -8,13 +8,17 @@ mod parser;
 pub(crate) use lexer::{LineLexer, LineToken, Token};
 pub(crate) use parser::LineCfg;
 
-use crate::TimeFile;
+use crate::{
+    error::{ParseError, ParseResult},
+    TimeFile,
+};
 use ir::{IrItem, IrStream};
 use std::{
     fs::{File, OpenOptions},
     io::{Read, Write},
 };
 
+/// A crate internal representation of the IR stream and timefile
 #[derive(Default)]
 pub(crate) struct ParseOutput {
     pub(crate) ir: IrStream,
@@ -22,46 +26,51 @@ pub(crate) struct ParseOutput {
 }
 
 impl ParseOutput {
-    fn append(mut self, ir: IrItem) -> Self {
-        self.tf.append(ir.clone());
+    fn append(mut self, ir: IrItem) -> ParseResult<Self> {
+        self.tf.append(ir.clone())?;
         self.ir.push(ir);
-        self
+        Ok(self)
     }
 }
 
 /// Load a file from disk and parse it into a
 /// [`TimeFile`](crate::TimeFile)
-pub(crate) fn load_file(path: &str) -> Option<ParseOutput> {
-    let mut f = File::open(path).ok()?;
+pub(crate) fn load_file(path: &str) -> ParseResult<ParseOutput> {
+    // Load the raw file contents
+    let mut f = File::open(path)?;
     let mut content = String::new();
-    f.read_to_string(&mut content).ok()?;
+    f.read_to_string(&mut content)?;
 
+    // Split the file by lines - .cass is a line based format
     let mut lines: Vec<String> = content.split("\n").map(|l| l.to_owned()).collect();
 
-    Some(
-        ir::generate_ir(
-            lines
-                .iter_mut()
-                .map(|line| lexer::lex(line))
-                .map(|lex| parser::parse(lex)),
-        )
+    // Build an iterator over parsed lines
+    let parsed = lines
+        .iter_mut()
+        .map(|line| lexer::lex(line))
+        .map(|lex| parser::parse(lex));
+
+    // Generate the IR from parse output, then build the timefile
+    ir::generate_ir(parsed)
         .into_iter()
-        .fold(ParseOutput::default(), |output, ir| output.append(ir)),
-    )
+        .fold(Ok(ParseOutput::default()), |out, ir| match out {
+            Ok(mut out) => out.append(ir),
+            e @ Err(_) => e,
+        })
 }
 
 /// Write a file with the updated IR stream
-pub(crate) fn write_file(path: &str, ir: &mut IrStream) -> Option<()> {
+pub(crate) fn write_file(path: &str, ir: &mut IrStream) -> ParseResult<()> {
     ir::update_header(ir);
     let mut lines = ir.into_iter().map(|ir| gen::line(ir)).collect::<Vec<_>>();
     lines.insert(0, gen::head_comment());
 
-    let mut f = OpenOptions::new()
-        .write(true)
-        .create(true)
-        .truncate(true)
-        .open(path)
-        .ok()?;
-    f.write_all(lines.join("\n").as_bytes()).ok()?;
-    Some(())
+    // let mut f = OpenOptions::new()
+    //     .write(true)
+    //     .create(true)
+    //     .truncate(true)
+    //     .open(path)
+    //     .ok()?;
+    // f.write_all(lines.join("\n").as_bytes()).ok()?;
+    Ok(())
 }