Parse tag directives

Author: DeltaEvo

examples/include_file_tag.rs

@@ -24,7 +24,7 @@ impl<'a> IncludeParser<'a> {
 impl<'a> yaml::YamlScalarParser for IncludeParser<'a> {
     fn parse_scalar(&self, tag: &scanner::TokenType, value: &str) -> Option<yaml::Yaml> {
         if let scanner::TokenType::Tag(ref handle, ref suffix) = *tag {
-            if *handle == "!" && *suffix == "include" {
+            if (*handle == "!" || *handle == "yaml-rust.include.prefix") && *suffix == "include" {
                 let mut content = String::new();
                 return Some(match File::open(self.root.join(value)){
                     Ok(mut f) => {

src/parser.rs

@@ -72,6 +72,7 @@ pub struct Parser<T> {
     token: Option<Token>,
     anchors: HashMap<String, usize>,
     anchor_id: usize,
+    tag_directives: HashMap<String, String>
 }
 
 
@@ -104,6 +105,7 @@ impl<T: Iterator<Item=char>> Parser<T> {
             anchors: HashMap::new(),
             // valid anchor_id starts from 1
             anchor_id: 1,
+            tag_directives: HashMap::new()
         }
     }
 
@@ -344,14 +346,14 @@ impl<T: Iterator<Item=char>> Parser<T> {
                     //        "found incompatible YAML document"));
                     //}
                 },
-                TokenType::TagDirective(..) => {
-                    // TODO add tag directive
+                TokenType::TagDirective(handle, mut prefix) => {
+                    prefix.pop(); //Remove :
+                    self.tag_directives.insert(handle , prefix);
                 },
                 _ => break
             }
             self.skip();
         }
-        // TODO tag directive
         Ok(())
     }
 
@@ -455,7 +457,19 @@ impl<T: Iterator<Item=char>> Parser<T> {
             TokenType::Scalar(style, v) => {
                 self.pop_state();
                 self.skip();
-                Ok((Event::Scalar(v, style, anchor_id, tag), tok.0))
+
+                Ok((if let Some(TokenType::Tag(handle, suffix)) = tag{
+                    let t = self.tag_directives.get(&handle);
+                    Event::Scalar(v, style, anchor_id, Some(
+                        if let Some(s) = t {
+                            TokenType::Tag((*s).clone() , suffix)
+                        } else {
+                            TokenType::Tag(handle , suffix)
+                        }
+                    ))
+                } else {
+                    Event::Scalar(v, style, anchor_id, tag)
+                }, tok.0))
             },
             TokenType::FlowSequenceStart => {
                 self.state = State::FlowSequenceFirstEntry;

src/yaml.rs

@@ -696,7 +696,7 @@ c: ~
     impl YamlScalarParser for HelloTagParser {
         fn parse_scalar(&self, tag: &TokenType, value: &str) -> Option<Yaml> {
             if let TokenType::Tag(ref handle, ref suffix) = *tag {
-                if *handle == "!" && *suffix == "hello" {
+                if (*handle == "!" || *handle == "yaml-rust.hello.prefix") && *suffix == "hello" {
                     return Some(Yaml::String("Hello ".to_string() + value))
                 }
             }
@@ -709,8 +709,23 @@ c: ~
         let parser = HelloTagParser;
         let mut loader = YamlLoader::new();
         loader.register_scalar_parser(&parser);
-        let out = loader.parse_from_str("- !hello world").unwrap();
+        let out = loader.parse_from_str("!hello world").unwrap();
         let doc = &out[0];
-        assert_eq!(doc[0].as_str().unwrap() , "Hello world")
+        assert_eq!(doc.as_str().unwrap() , "Hello world")
+    }
+
+    #[test]
+    fn test_tag_directive() {
+        let parser = HelloTagParser;
+        let mut loader = YamlLoader::new();
+        loader.register_scalar_parser(&parser);
+        let out = loader.parse_from_str(
+"%YAML 1.2
+%TAG ! yaml-rust.hello.prefix:
+---
+!hello world"
+        ).unwrap();
+        let doc = &out[0];
+        assert_eq!(doc.as_str().unwrap() , "Hello world")
     }
 }