cassiopeia: finishing up version 0.3.0

This commit does kind of a lot to get cass(1) over the finish line.
For one it implements all the CLI functions (well, almost all) with
their respective parameters, and also creates a new `gen` module which
uses the IR stream to generate a new file based on the old one, while
updating header fields that need to be updated (currently only
`version`).

This version does nothing with the actual header values, and probably
has a lot of bugs.  More documentation will follow in future
cassiopeia commits.

1 files changed, 25 insertions, 5 deletions

diff --git a/apps/cassiopeia/src/format/mod.rs b/apps/cassiopeia/src/format/mod.rs
index 814c08656dbe..89f3a6ccb466 100644
--- a/apps/cassiopeia/src/format/mod.rs
+++ b/apps/cassiopeia/src/format/mod.rs
@@ -1,18 +1,22 @@
 //! cassiopeia file format
 
-mod ir;
+mod gen;
+pub(crate) mod ir;
 mod lexer;
 mod parser;
 
-pub(crate) use ir::{IrItem, IrStream, IrType, MakeIr};
 pub(crate) use lexer::{LineLexer, LineToken, Token};
 pub(crate) use parser::LineCfg;
 
 use crate::TimeFile;
-use std::{fs::File, io::Read};
+use ir::{IrItem, IrStream};
+use std::{
+    fs::{File, OpenOptions},
+    io::{Read, Write},
+};
 
 #[derive(Default)]
-pub struct ParseOutput {
+pub(crate) struct ParseOutput {
     pub(crate) ir: IrStream,
     pub(crate) tf: TimeFile,
 }
@@ -27,7 +31,7 @@ impl ParseOutput {
 
 /// Load a file from disk and parse it into a
 /// [`TimeFile`](crate::TimeFile)
-pub fn load_file(path: &str) -> Option<ParseOutput> {
+pub(crate) fn load_file(path: &str) -> Option<ParseOutput> {
     let mut f = File::open(path).ok()?;
     let mut content = String::new();
     f.read_to_string(&mut content).ok()?;
@@ -45,3 +49,19 @@ pub fn load_file(path: &str) -> Option<ParseOutput> {
         .fold(ParseOutput::default(), |output, ir| output.append(ir)),
     )
 }
+
+/// Write a file with the updated IR stream
+pub(crate) fn write_file(path: &str, ir: &mut IrStream) -> Option<()> {
+    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(())
+}