Fix index in error messages

cli/src/main.rs

@@ -12,10 +12,16 @@ fn get_input() -> String {
 }
 
 fn main() {
-    loop {
-        let input = get_input();
-        core::evaluate(&input);
+    // loop {
+    //     let input = get_input();
+    //     match core::evaluate(&input) {
+    //         Ok(()) => continue,
+    //         Err(msg) => eprintln!("{msg}"),
+    //     }
+    // }
+    let input = include_str!("../../test/hello.lox");
+    match core::evaluate(input) {
+        Ok(()) => {},
+        Err(msg) => eprintln!("{msg}"),
     }
-    // let input = include_str!("../../test/hello.lox");
-    // core::evaluate(&input);
 }

core/src/error.rs

@@ -16,8 +16,8 @@ impl From<(u16, u16)> for Index {
 }
 
 impl fmt::Display for Index {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "at line {}, column {}", self.row, self.column)
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "line {}, column {}", self.row, self.column)
     }
 }
 
@@ -28,11 +28,11 @@ pub enum BessyError {
 }
 
 impl fmt::Display for BessyError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         use BessyError::*;
         match self {
             UnterminatedString(span) => {
-                write!(f, "Lex error: Unterminated String Literal at {span}.")
+                write!(f, "Syntax Error: Unterminated string literal at {span}.")
             }
             Unexpected { msg, span } => write!(f, "Parse error: {msg} at {span}."),
         }

core/src/lexer.rs

@@ -79,6 +79,7 @@ pub struct Lexer<'src> {
     cursor: Peekable<CharIndices<'src>>,
     tokens: Vec<Token>,
     line: u16,
+    consumed: u16,
 }
 
 impl<'src> Lexer<'src> {
@@ -87,6 +88,7 @@ impl<'src> Lexer<'src> {
             cursor: text.char_indices().peekable(),
             tokens: vec![],
             line: 1,
+            consumed: 0,
         }
     }
 
@@ -101,7 +103,11 @@ impl<'src> Lexer<'src> {
                 ' ' | '\r' | '\t' => {
                     self.cursor.next();
                 }
-                '\n' => self.line += 1,
+                '\n' => {
+                    let (index, _) = self.cursor.next().unwrap();
+                    self.line += 1;
+                    self.consumed = index as u16;
+                }
                 '"' => {
                     let token = self.scan_string()?;
                     self.tokens.push(token);
@@ -149,8 +155,10 @@ impl<'src> Lexer<'src> {
     }
 
     fn scan_comment(&mut self) {
-        for (_, ch) in self.cursor.by_ref() {
+        for (index, ch) in self.cursor.by_ref() {
             if ch == '\n' {
+                self.line += 1;
+                self.consumed = index as u16;
                 break;
             }
         }
@@ -221,8 +229,9 @@ impl<'src> Lexer<'src> {
                 self.line,
             ))
         } else {
+            let column = start as u16 - self.consumed;
             Err(BessyError::UnterminatedString(
-                (start_pos as u16, self.line).into(),
+                (self.line, column - 2).into(),
             ))
         }
     }

core/src/lib.rs

@@ -4,9 +4,13 @@ mod lexer;
 mod parser;
 mod stmt;
 
-pub fn evaluate(text: &str) {
+use crate::error::BessyError;
+
+pub fn evaluate(text: &str) -> Result<(), BessyError> {
     let mut lex = lexer::Lexer::new(text);
-    let tokens = lex.scan().unwrap();
+    let tokens = lex.scan()?;
     println!("Tokens: {tokens:?}");
-    let mut parser = parser::Parser::new(tokens.into_iter());
+    Ok(())
+    // let mut parser = parser::Parser::new(tokens.into_iter());
+    // parser.parse();
 }

core/src/parser.rs

@@ -23,7 +23,7 @@ impl<T: Iterator<Item = Token>> Parser<T> {
         }
     }
 
-    pub fn parse() -> Result<Vec<Stmt>, BessyError> {
+    pub fn parse(&mut self) -> Result<Vec<Stmt>, BessyError> {
         todo!()
     }
 }

test/hello.lox

@@ -1,4 +1,5 @@
 ~ comment comment
 fun hello() {
-   print("hello);
+    print("hello" + "world" + "wat);
+    var a = 10;
 }