cleanup

Cargo.toml

@@ -2,10 +2,12 @@
 name = "synmtx"
 version = "0.1.0"
 edition = "2021"
+authors = ["LordMZTE <lord@mzte.de>"]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 clap = { version = "3.0.0-beta.5", features = ["derive"] }
 html-escape = "0.2.9"
+miette = { version = "3.2.0", features = ["fancy"] }
 syntect = "4.6.0"

src/main.rs

@@ -3,7 +3,8 @@ use std::{
     path::PathBuf,
 };
 
-use clap::Parser;
+use clap::{crate_authors, crate_version, Parser};
+use miette::{bail, IntoDiagnostic, WrapErr};
 use syntect::{
     easy::HighlightFile,
     highlighting::{Color, Style, ThemeSet},
@@ -11,7 +12,22 @@ use syntect::{
 };
 
 #[derive(Parser)]
+#[clap(
+    version = crate_version!(),
+    author = crate_authors!(),
+)]
 struct Opt {
+    #[clap(subcommand)]
+    cmd: Cmd,
+}
+
+#[derive(Parser)]
+enum Cmd {
+    #[clap(about = "Print available themes and exit")]
+    ListThemes,
+
+    #[clap(about = "Highlight a file", alias = "hl")]
+    Highlight {
         #[clap(about = "The file to highlight")]
         file: PathBuf,
 
@@ -22,34 +38,46 @@ struct Opt {
             about = "The color scheme to use"
         )]
         theme: String,
+    },
 }
 
-fn main() {
+fn main() -> miette::Result<()> {
     let opt = Opt::parse();
 
-    let ss = SyntaxSet::load_defaults_newlines();
     let mut ts = ThemeSet::load_defaults();
     ts.themes.insert(
         "dracula".to_string(),
+        // TODO: do expensive tmTheme parsing in build script
         ThemeSet::load_from_reader(&mut Cursor::new(include_bytes!(
             "../assets/dracula_theme/Dracula.tmTheme"
         )))
-        .expect("Failed to load static dracula theme"),
+        .into_diagnostic()
+        .wrap_err("Failed to load static dracula theme")?,
     );
 
-    let theme = if let Some(t) = ts.themes.get(&opt.theme) {
+    match opt.cmd {
+        Cmd::ListThemes => {
+            for theme in ts.themes.keys() {
+                println!("{}", theme);
+            }
+
+            Ok(())
+        },
+        Cmd::Highlight { file, theme } => {
+            let ss = SyntaxSet::load_defaults_newlines();
+            let theme = if let Some(t) = ts.themes.get(&theme) {
                 t
             } else {
-        eprintln!("No such theme!");
+                bail!("No such theme! Use list-themes to list themes.");
-        // TODO dont exit successfully
-        return;
             };
 
-    let mut h = HighlightFile::new(opt.file, &ss, theme).unwrap();
+            let mut h = HighlightFile::new(file, &ss, theme)
+                .into_diagnostic()
+                .wrap_err("Failed to open file")?;
 
             print!("<pre>");
             for line in h.reader.lines() {
-        let line = line.unwrap();
+                let line = line.into_diagnostic().wrap_err("Failed to read file")?;
                 let regions = h.highlight_lines.highlight(&line, &ss);
 
                 for (
@@ -72,4 +100,8 @@ fn main() {
                 println!();
             }
             println!("</pre>");
+
+            Ok(())
+        },
+    }
 }