feat: add error framework

Currently implemented:
- SyntaxError
- IO error

src/error.rs

@@ -0,0 +1,42 @@
+use core::fmt;
+
+#[derive(Debug, Clone)]
+pub struct SyntaxError {
+    line: u32,
+    location: String,
+    message: String,
+}
+
+impl fmt::Display for SyntaxError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "[line {} ] Error {}: {}",self.line, self.location, self.message)
+    }
+}
+
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum RunError {
+    Io(std::io::Error),
+    Syntax(SyntaxError)
+}
+
+impl fmt::Display for RunError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            RunError::Io(err) => write!(f, "IO Error: {}", err),
+            RunError::Syntax(err) => write!(f, "Syntax Error: {}", err),
+        }
+    }
+}
+
+impl From<std::io::Error> for RunError {
+    fn from(err: std::io::Error) -> RunError {
+        RunError::Io(err)
+    }
+}
+
+impl From<SyntaxError> for RunError {
+    fn from(err: SyntaxError) -> RunError {
+        RunError::Syntax(err)
+    }
+}

src/main.rs

@@ -1,3 +1,6 @@
+mod error;
+use error::RunError;
+
 use clap::Parser;
 use std::fs::File;
 use std::io::{self, BufRead, Write};
@@ -10,20 +13,27 @@ struct Args {
     script: Option<String>,
 }
 
-fn run(lines: io::Lines<io::BufReader<File>>) {
-    for line in lines {
-        println!("Line: {}", line.unwrap());
-    }
+fn run_line(line: String) -> Result<(), RunError> {
+    println!("Line: {}", line);
+    Ok(())
 }
 
-fn run_file(script: String) -> Result<(), io::Error> {
-    let file = File::open(script)?;
-    run(io::BufReader::new(file).lines());
+fn run(lines: io::Lines<io::BufReader<File>>) -> Result<(), RunError> {
+    for line in lines {
+        run_line(line.unwrap())?;
+    }
 
     Ok(())
 }
 
-fn run_prompt() -> Result<(), io::Error> {
+fn run_file(script: String) -> Result<(), RunError> {
+    let file = File::open(script)?;
+    run(io::BufReader::new(file).lines())?;
+
+    Ok(())
+}
+
+fn run_prompt() -> Result<(), RunError> {
     loop {
         print!("> ");
         io::stdout().flush()?;
@@ -34,12 +44,16 @@ fn run_prompt() -> Result<(), io::Error> {
             break;
         }
         println!("input: '{}', {}", buffer, buffer.len());
+        match run_line(buffer) {
+            Ok(()) => continue,
+            Err(error) => println!("{}", error),
+        };
     }
 
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn std::error::Error>> {
+fn main() -> Result<(), RunError> {
     let args = Args::parse();
 
     if let Some(script) = args.script {