Implement Iterator for Parser and Scanner

src/document.rs

@@ -259,8 +259,7 @@ impl Document {
     /// end has been reached.
     ///
     /// An application must not alternate the calls of [`Document::load()`] with
-    /// the calls of [`yaml_parser_scan()`](crate::yaml_parser_scan) or
-    /// [`Parser::parse()`]. Doing this will break the parser.
+    /// the calls of [`Parser::parse()`]. Doing this will break the parser.
     pub fn load(parser: &mut Parser) -> Result<Document, ComposerError> {
         let mut document = Document::new(None, &[], false, false);
         document.nodes.reserve(16);

src/parser.rs

@@ -164,6 +164,20 @@ fn SKIP_TOKEN(parser: &mut Parser) {
     );
 }
 
+impl<'r> Iterator for Parser<'r> {
+    type Item = Result<Event, ParserError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.scanner.stream_end_produced || self.state == ParserState::End {
+            None
+        } else {
+            Some(self.parse())
+        }
+    }
+}
+
+impl<'r> core::iter::FusedIterator for Parser<'r> {}
+
 impl<'r> Parser<'r> {
     /// Create a parser.
     pub fn new() -> Parser<'r> {
@@ -206,9 +220,8 @@ impl<'r> Parser<'r> {
     /// [`EventData::StreamEnd`](crate::EventData::StreamEnd).
     ///
     /// An application must not alternate the calls of [`Parser::parse()`] with
-    /// the calls of [`yaml_parser_scan()`](crate::yaml_parser_scan) or
-    /// [`Document::load()`](crate::Document::load). Doing this will break the
-    /// parser.
+    /// the calls of [`Document::load()`](crate::Document::load). Doing this
+    /// will break the parser.
     pub fn parse(&mut self) -> Result<Event, ParserError> {
         if self.scanner.stream_end_produced || self.state == ParserState::End {
             return Ok(Event {

src/scanner.rs

@@ -180,18 +180,27 @@ fn READ_LINE_STRING(scanner: &mut Scanner, string: &mut String) {
     }
 }
 
+impl<'r> Iterator for Scanner<'r> {
+    type Item = Result<Token, ScannerError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.stream_end_produced {
+            None
+        } else {
+            Some(self.scan())
+        }
+    }
+}
+
+impl<'r> core::iter::FusedIterator for Scanner<'r> {}
+
 impl<'r> Scanner<'r> {
     /// Scan the input stream and produce the next token.
     ///
-    /// Call the function subsequently to produce a sequence of tokens corresponding
-    /// to the input stream. The initial token has the type
+    /// Call the function subsequently to produce a sequence of tokens
+    /// corresponding to the input stream. The initial token has the type
     /// [`TokenData::StreamStart`] while the ending token has the type
     /// [`TokenData::StreamEnd`].
-    ///
-    /// An application must not alternate the calls of
-    /// [`yaml_parser_scan()`](crate::yaml_parser_scan) with the calls of
-    /// [`Parser::parse()`] or [`Document::load()`](crate::Document::load). Doing
-    /// this will break the parser.
     pub fn scan(&mut self) -> Result<Token, ScannerError> {
         if self.stream_end_produced {
             return Ok(Token {