error with source printing

examples/parse.rs

@@ -19,6 +19,6 @@ fn main() {
 
     match parse(source) {
         Ok(result) => print!("{:#?}", result),
-        Err(err) => eprint!("{}", err),
+        Err(err) => eprint!("{}", err.with_source(source)),
     }
 }

src/error.rs

@@ -14,7 +14,7 @@ use thiserror::Error;
 
 /// An error and related source span
 ///
-/// You can pretty-print the error with the offending source by using `display_with_source`
+/// You can pretty-print the error with the offending source by using `with_source`
 ///
 /// ## Example
 ///
@@ -42,6 +42,14 @@ impl<T: Error + Debug> SpannedError<T> {
     pub fn error(&self) -> &T {
         &self.error
     }
+
+    pub fn with_source(self, source: &str) -> SourceSpannedError<T> {
+        SourceSpannedError {
+            span: self.span,
+            error: self.error,
+            source,
+        }
+    }
 }
 
 impl<T: Error + Debug + 'static> Error for SpannedError<T> {
@@ -56,17 +64,23 @@ impl<T: Error + Debug> Display for SpannedError<T> {
     }
 }
 
+pub struct SourceSpannedError<'source, T> {
+    span: Span,
+    error: T,
+    source: &'source str,
+}
+
 const METRICS: DefaultMetrics = DefaultMetrics::with_tab_stop(4);
 
-impl<T: Error + Debug> SpannedError<T> {
-    pub fn display_with_source(&self, source: &str, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let start = get_position(source, self.span.start);
-        let end = get_position(source, self.span.end);
+impl<'source, T: Error + Debug> Display for SourceSpannedError<'source, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let start = get_position(self.source, self.span.start);
+        let end = get_position(self.source, self.span.end);
         let span = SourceSpan::new(start, end, end.next_line());
 
         let mut fmt = Formatter::with_margin_color(Color::Blue);
         let buffer = SourceBuffer::new(
-            source.chars().map(|char| Result::<char, ()>::Ok(char)),
+            self.source.chars().map(|char| Result::<char, ()>::Ok(char)),
             Position::default(),
             METRICS,
         );

src/lexer.rs

@@ -186,14 +186,6 @@ impl<'source> TokenStream<'source> {
     pub fn new(lexer: Lexer<'source, Token>) -> Self {
         TokenStream { lexer }
     }
-
-    pub fn source(&self) -> &'source str {
-        self.lexer.source()
-    }
-
-    pub fn span(&self) -> Span {
-        self.lexer.span()
-    }
 }
 
 impl<'source> Iterator for TokenStream<'source> {

src/parser.rs

@@ -30,14 +30,12 @@ pub fn parse(source: &str) -> Result<Value, SpannedError<ParseError>> {
 }
 
 pub struct Parser<'source> {
-    source: &'source str,
     tokens: TokenStream<'source>,
 }
 
 impl<'source> Parser<'source> {
     pub fn new(source: &'source str) -> Self {
         Parser {
-            source,
             tokens: TokenStream::new(Token::lexer(source)),
         }
     }