vendor/yaml-rust/src/yaml.rs - toolchain/rustc - Git at Google

 use std::collections::BTreeMap;
 use std::ops::Index;
 use std::string;
 use std::i64;
 use std::str::FromStr;
 use std::mem;
 use std::vec;
 use parser::*;
 use scanner::{TScalarStyle, ScanError, TokenType, Marker};

 /// A YAML node is stored as this `Yaml` enumeration, which provides an easy way to
 /// access your YAML document.
 ///
 /// # Examples
 ///
 /// ```
 /// use yaml_rust::Yaml;
 /// let foo = Yaml::from_str("-123"); // convert the string to the appropriate YAML type
 /// assert_eq!(foo.as_i64().unwrap(), -123);
 ///
 /// // iterate over an Array
 /// let vec = Yaml::Array(vec![Yaml::Integer(1), Yaml::Integer(2)]);
 /// for v in vec.as_vec().unwrap() {
 ///     assert!(v.as_i64().is_some());
 /// }
 /// ```
 #[derive(Clone, PartialEq, PartialOrd, Debug, Eq, Ord, Hash)]
 pub enum Yaml {
     /// Float types are stored as String and parsed on demand.
     /// Note that f64 does NOT implement Eq trait and can NOT be stored in BTreeMap.
     Real(string::String),
     /// YAML int is stored as i64.
     Integer(i64),
     /// YAML scalar.
     String(string::String),
     /// YAML bool, e.g. `true` or `false`.
     Boolean(bool),
     /// YAML array, can be accessed as a `Vec`.
     Array(self::Array),
     /// YAML hash, can be accessed as a `BTreeMap`.
     ///
     /// If the order of keys is meaningful, enable the `preserve_order` feature to
     /// store hashes as a `LinkedHashMap` intead of `BTreeMap`. When using a
     /// `LinkedHashMap`, the itertion order will match the order of insertion into
     /// the map.
     ///
     /// ```toml
     /// yaml-rust = { version = "*", features = ["preserve_order"] }
     /// ```
     Hash(self::Hash),
     /// Alias, not fully supported yet.
     Alias(usize),
     /// YAML null, e.g. `null` or `~`.
     Null,
     /// Accessing a nonexistent node via the Index trait returns `BadValue`. This
     /// simplifies error handling in the calling code. Invalid type conversion also
     /// returns `BadValue`.
     BadValue,
 }

 pub type Array = Vec<Yaml>;

 #[cfg(not(feature = "preserve_order"))]
 pub type Hash = BTreeMap<Yaml, Yaml>;
 #[cfg(feature = "preserve_order")]
 pub type Hash = ::linked_hash_map::LinkedHashMap<Yaml, Yaml>;

 pub struct YamlLoader {
     docs: Vec<Yaml>,
     // states
     // (current node, anchor_id) tuple
     doc_stack: Vec<(Yaml, usize)>,
     key_stack: Vec<Yaml>,
     anchor_map: BTreeMap<usize, Yaml>,
 }

 impl MarkedEventReceiver for YamlLoader {
     fn on_event(&mut self, ev: &Event, _: Marker) {
         // println!("EV {:?}", ev);
         match *ev {
             Event::DocumentStart => {
                 // do nothing
             },
             Event::DocumentEnd => {
                 match self.doc_stack.len() {
                     // empty document
                     0 => self.docs.push(Yaml::BadValue),
                     1 => self.docs.push(self.doc_stack.pop().unwrap().0),
                     _ => unreachable!()
                 }
             },
             Event::SequenceStart(aid) => {
                 self.doc_stack.push((Yaml::Array(Vec::new()), aid));
             },
             Event::SequenceEnd => {
                 let node = self.doc_stack.pop().unwrap();
                 self.insert_new_node(node);
             },
             Event::MappingStart(aid) => {
                 self.doc_stack.push((Yaml::Hash(Hash::new()), aid));
                 self.key_stack.push(Yaml::BadValue);
             },
             Event::MappingEnd => {
                 self.key_stack.pop().unwrap();
                 let node = self.doc_stack.pop().unwrap();
                 self.insert_new_node(node);
             },
             Event::Scalar(ref v, style, aid, ref tag) => {
                 let node = if style != TScalarStyle::Plain {
                     Yaml::String(v.clone())
                 } else if let Some(TokenType::Tag(ref handle, ref suffix)) = *tag {
                     // XXX tag:yaml.org,2002:
                     if handle == "!!" {
                         match suffix.as_ref() {
                             "bool" => {
                                 // "true" or "false"
                                 match v.parse::<bool>() {
                                     Err(_) => Yaml::BadValue,
                                     Ok(v) => Yaml::Boolean(v)
                                 }
                             },
                             "int" => {
                                 match v.parse::<i64>() {
                                     Err(_) => Yaml::BadValue,
                                     Ok(v) => Yaml::Integer(v)
                                 }
                             },
                             "float" => {
                                 match v.parse::<f64>() {
                                     Err(_) => Yaml::BadValue,
                                     Ok(_) => Yaml::Real(v.clone())
                                 }
                             },
                             "null" => {
                                 match v.as_ref() {
                                     "~" | "null" => Yaml::Null,
                                     _ => Yaml::BadValue,
                                 }
                             }
                             _  => Yaml::String(v.clone()),
                         }
                     } else {
                         Yaml::String(v.clone())
                     }
                 } else {
                     // Datatype is not specified, or unrecognized
                     Yaml::from_str(v.as_ref())
                 };

                 self.insert_new_node((node, aid));
             },
             Event::Alias(id) => {
                 let n = match self.anchor_map.get(&id) {
                     Some(v) => v.clone(),
                     None => Yaml::BadValue,
                 };
                 self.insert_new_node((n, 0));
             }
             _ => { /* ignore */ }
         }
         // println!("DOC {:?}", self.doc_stack);
     }
 }

 impl YamlLoader {
     fn insert_new_node(&mut self, node: (Yaml, usize)) {
         // valid anchor id starts from 1
         if node.1 > 0 {
             self.anchor_map.insert(node.1, node.0.clone());
         }
         if self.doc_stack.is_empty() {
             self.doc_stack.push(node);
         } else {
             let parent = self.doc_stack.last_mut().unwrap();
             match *parent {
                 (Yaml::Array(ref mut v), _) => v.push(node.0),
                 (Yaml::Hash(ref mut h), _) => {
                     let mut cur_key = self.key_stack.last_mut().unwrap();
                     // current node is a key
                     if cur_key.is_badvalue() {
                         *cur_key = node.0;
                     // current node is a value
                     } else {
                         let mut newkey = Yaml::BadValue;
                         mem::swap(&mut newkey, cur_key);
                         h.insert(newkey, node.0);
                     }
                 },
                 _ => unreachable!(),
             }
         }
     }

     pub fn load_from_str(source: &str) -> Result<Vec<Yaml>, ScanError>{
         let mut loader = YamlLoader {
             docs: Vec::new(),
             doc_stack: Vec::new(),
             key_stack: Vec::new(),
             anchor_map: BTreeMap::new(),
         };
         let mut parser = Parser::new(source.chars());
         try!(parser.load(&mut loader, true));
         Ok(loader.docs)
     }
 }

 macro_rules! define_as (
     ($name:ident, $t:ident, $yt:ident) => (
 pub fn $name(&self) -> Option<$t> {
     match *self {
         Yaml::$yt(v) => Some(v),
         _ => None
     }
 }
     );
 );

 macro_rules! define_as_ref (
     ($name:ident, $t:ty, $yt:ident) => (
 pub fn $name(&self) -> Option<$t> {
     match *self {
         Yaml::$yt(ref v) => Some(v),
         _ => None
     }
 }
     );
 );

 macro_rules! define_into (
     ($name:ident, $t:ty, $yt:ident) => (
 pub fn $name(self) -> Option<$t> {
     match self {
         Yaml::$yt(v) => Some(v),
         _ => None
     }
 }
     );
 );

 impl Yaml {
     define_as!(as_bool, bool, Boolean);
     define_as!(as_i64, i64, Integer);

     define_as_ref!(as_str, &str, String);
     define_as_ref!(as_hash, &Hash, Hash);
     define_as_ref!(as_vec, &Array, Array);

     define_into!(into_bool, bool, Boolean);
     define_into!(into_i64, i64, Integer);
     define_into!(into_string, String, String);
     define_into!(into_hash, Hash, Hash);
     define_into!(into_vec, Array, Array);

     pub fn is_null(&self) -> bool {
         match *self {
             Yaml::Null => true,
             _ => false
         }
     }

     pub fn is_badvalue(&self) -> bool {
         match *self {
             Yaml::BadValue => true,
             _ => false
         }
     }

     pub fn as_f64(&self) -> Option<f64> {
         match *self {
             Yaml::Real(ref v) => {
                 v.parse::<f64>().ok()
             },
             _ => None
         }
     }

     pub fn into_f64(self) -> Option<f64> {
         match self {
             Yaml::Real(v) => {
                 v.parse::<f64>().ok()
             },
             _ => None
         }
     }
 }

 #[cfg_attr(feature="clippy", allow(should_implement_trait))]
 impl Yaml {
     // Not implementing FromStr because there is no possibility of Error.
     // This function falls back to Yaml::String if nothing else matches.
     pub fn from_str(v: &str) -> Yaml {
         if v.starts_with("0x") {
             let n = i64::from_str_radix(&v[2..], 16);
             if n.is_ok() {
                 return Yaml::Integer(n.unwrap());
             }
         }
         if v.starts_with("0o") {
             let n = i64::from_str_radix(&v[2..], 8);
             if n.is_ok() {
                 return Yaml::Integer(n.unwrap());
             }
         }
         if v.starts_with('+') && v[1..].parse::<i64>().is_ok() {
             return Yaml::Integer(v[1..].parse::<i64>().unwrap());
         }
         match v {
             "~" | "null" => Yaml::Null,
             "true" => Yaml::Boolean(true),
             "false" => Yaml::Boolean(false),
             _ if v.parse::<i64>().is_ok() => Yaml::Integer(v.parse::<i64>().unwrap()),
             // try parsing as f64
             _ if v.parse::<f64>().is_ok() => Yaml::Real(v.to_owned()),
             _ => Yaml::String(v.to_owned())
         }
     }
 }

 static BAD_VALUE: Yaml = Yaml::BadValue;
 impl<'a> Index<&'a str> for Yaml {
     type Output = Yaml;

     fn index(&self, idx: &'a str) -> &Yaml {
         let key = Yaml::String(idx.to_owned());
         match self.as_hash() {
             Some(h) => h.get(&key).unwrap_or(&BAD_VALUE),
             None => &BAD_VALUE
         }
     }
 }

 impl Index<usize> for Yaml {
     type Output = Yaml;

     fn index(&self, idx: usize) -> &Yaml {
         match self.as_vec() {
             Some(v) => v.get(idx).unwrap_or(&BAD_VALUE),
             None => &BAD_VALUE
         }
     }
 }

 impl IntoIterator for Yaml {
     type Item = Yaml;
     type IntoIter = YamlIter;

     fn into_iter(self) -> Self::IntoIter {
         YamlIter {
             yaml: self.into_vec()
                 .unwrap_or_else(Vec::new).into_iter()
         }
     }
 }

 pub struct YamlIter {
     yaml: vec::IntoIter<Yaml>,
 }

 impl Iterator for YamlIter {
     type Item = Yaml;

     fn next(&mut self) -> Option<Yaml> {
         self.yaml.next()
     }
 }

 #[cfg(test)]
 mod test {
     use yaml::*;
     #[test]
     fn test_coerce() {
         let s = "---
 a: 1
 b: 2.2
 c: [1, 2]
 ";
         let out = YamlLoader::load_from_str(&s).unwrap();
         let doc = &out[0];
         assert_eq!(doc["a"].as_i64().unwrap(), 1i64);
         assert_eq!(doc["b"].as_f64().unwrap(), 2.2f64);
         assert_eq!(doc["c"][1].as_i64().unwrap(), 2i64);
         assert!(doc["d"][0].is_badvalue());
     }

     #[test]
     fn test_empty_doc() {
         let s: String = "".to_owned();
         YamlLoader::load_from_str(&s).unwrap();
         let s: String = "---".to_owned();
         assert_eq!(YamlLoader::load_from_str(&s).unwrap()[0], Yaml::Null);
     }

     #[test]
     fn test_parser() {
         let s: String = "
 # comment
 a0 bb: val
 a1:
     b1: 4
     b2: d
 a2: 4 # i'm comment
 a3: [1, 2, 3]
 a4:
     - - a1
       - a2
     - 2
 a5: 'single_quoted'
 a6: \"double_quoted\"
 a7: 你好
 ".to_owned();
         let out = YamlLoader::load_from_str(&s).unwrap();
         let doc = &out[0];
         assert_eq!(doc["a7"].as_str().unwrap(), "你好");
     }

     #[test]
     fn test_multi_doc() {
         let s =
 "
 'a scalar'
 ---
 'a scalar'
 ---
 'a scalar'
 ";
         let out = YamlLoader::load_from_str(&s).unwrap();
         assert_eq!(out.len(), 3);
     }

     #[test]
     fn test_anchor() {
         let s =
 "
 a1: &DEFAULT
     b1: 4
     b2: d
 a2: *DEFAULT
 ";
         let out = YamlLoader::load_from_str(&s).unwrap();
         let doc = &out[0];
         assert_eq!(doc["a2"]["b1"].as_i64().unwrap(), 4);
     }

     #[test]
     fn test_bad_anchor() {
         let s =
 "
 a1: &DEFAULT
     b1: 4
     b2: *DEFAULT
 ";
         let out = YamlLoader::load_from_str(&s).unwrap();
         let doc = &out[0];
         assert_eq!(doc["a1"]["b2"], Yaml::BadValue);

     }

     #[test]
     fn test_github_27() {
         // https://github.com/chyh1990/yaml-rust/issues/27
         let s = "&a";
         let out = YamlLoader::load_from_str(&s).unwrap();
         let doc = &out[0];
         assert_eq!(doc.as_str().unwrap(), "");
     }

     #[test]
     fn test_plain_datatype() {
         let s =
 "
 - 'string'
 - \"string\"
 - string
 - 123
 - -321
 - 1.23
 - -1e4
 - ~
 - null
 - true
 - false
 - !!str 0
 - !!int 100
 - !!float 2
 - !!null ~
 - !!bool true
 - !!bool false
 - 0xFF
 # bad values
 - !!int string
 - !!float string
 - !!bool null
 - !!null val
 - 0o77
 - [ 0xF, 0xF ]
 - +12345
 - [ true, false ]
 ";
         let out = YamlLoader::load_from_str(&s).unwrap();
         let doc = &out[0];

         assert_eq!(doc[0].as_str().unwrap(), "string");
         assert_eq!(doc[1].as_str().unwrap(), "string");
         assert_eq!(doc[2].as_str().unwrap(), "string");
         assert_eq!(doc[3].as_i64().unwrap(), 123);
         assert_eq!(doc[4].as_i64().unwrap(), -321);
         assert_eq!(doc[5].as_f64().unwrap(), 1.23);
         assert_eq!(doc[6].as_f64().unwrap(), -1e4);
         assert!(doc[7].is_null());
         assert!(doc[8].is_null());
         assert_eq!(doc[9].as_bool().unwrap(), true);
         assert_eq!(doc[10].as_bool().unwrap(), false);
         assert_eq!(doc[11].as_str().unwrap(), "0");
         assert_eq!(doc[12].as_i64().unwrap(), 100);
         assert_eq!(doc[13].as_f64().unwrap(), 2.0);
         assert!(doc[14].is_null());
         assert_eq!(doc[15].as_bool().unwrap(), true);
         assert_eq!(doc[16].as_bool().unwrap(), false);
         assert_eq!(doc[17].as_i64().unwrap(), 255);
         assert!(doc[18].is_badvalue());
         assert!(doc[19].is_badvalue());
         assert!(doc[20].is_badvalue());
         assert!(doc[21].is_badvalue());
         assert_eq!(doc[22].as_i64().unwrap(), 63);
         assert_eq!(doc[23][0].as_i64().unwrap(), 15);
         assert_eq!(doc[23][1].as_i64().unwrap(), 15);
         assert_eq!(doc[24].as_i64().unwrap(), 12345);
         assert!(doc[25][0].as_bool().unwrap());
         assert!(!doc[25][1].as_bool().unwrap());
     }

     #[test]
     fn test_bad_hypen() {
         // See: https://github.com/chyh1990/yaml-rust/issues/23
         let s = "{-";
         assert!(YamlLoader::load_from_str(&s).is_err());
     }

     #[test]
     fn test_bad_docstart() {
         assert!(YamlLoader::load_from_str("---This used to cause an infinite loop").is_ok());
         assert_eq!(YamlLoader::load_from_str("----"), Ok(vec![Yaml::String(String::from("----"))]));
         assert_eq!(YamlLoader::load_from_str("--- #here goes a comment"), Ok(vec![Yaml::Null]));
         assert_eq!(YamlLoader::load_from_str("---- #here goes a comment"), Ok(vec![Yaml::String(String::from("----"))]));
     }

     #[test]
     fn test_plain_datatype_with_into_methods() {
         let s =
 "
 - 'string'
 - \"string\"
 - string
 - 123
 - -321
 - 1.23
 - -1e4
 - true
 - false
 - !!str 0
 - !!int 100
 - !!float 2
 - !!bool true
 - !!bool false
 - 0xFF
 - 0o77
 - +12345
 ";
         let mut out = YamlLoader::load_from_str(&s).unwrap().into_iter();
         let mut doc = out.next().unwrap().into_iter();

         assert_eq!(doc.next().unwrap().into_string().unwrap(), "string");
         assert_eq!(doc.next().unwrap().into_string().unwrap(), "string");
         assert_eq!(doc.next().unwrap().into_string().unwrap(), "string");
         assert_eq!(doc.next().unwrap().into_i64().unwrap(), 123);
         assert_eq!(doc.next().unwrap().into_i64().unwrap(), -321);
         assert_eq!(doc.next().unwrap().into_f64().unwrap(), 1.23);
         assert_eq!(doc.next().unwrap().into_f64().unwrap(), -1e4);
         assert_eq!(doc.next().unwrap().into_bool().unwrap(), true);
         assert_eq!(doc.next().unwrap().into_bool().unwrap(), false);
         assert_eq!(doc.next().unwrap().into_string().unwrap(), "0");
         assert_eq!(doc.next().unwrap().into_i64().unwrap(), 100);
         assert_eq!(doc.next().unwrap().into_f64().unwrap(), 2.0);
         assert_eq!(doc.next().unwrap().into_bool().unwrap(), true);
         assert_eq!(doc.next().unwrap().into_bool().unwrap(), false);
         assert_eq!(doc.next().unwrap().into_i64().unwrap(), 255);
         assert_eq!(doc.next().unwrap().into_i64().unwrap(), 63);
         assert_eq!(doc.next().unwrap().into_i64().unwrap(), 12345);
     }
 }
	use std::collections::BTreeMap;
	use std::ops::Index;
	use std::string;
	use std::i64;
	use std::str::FromStr;
	use std::mem;
	use std::vec;
	use parser::*;
	use scanner::{TScalarStyle, ScanError, TokenType, Marker};

	/// A YAML node is stored as this `Yaml` enumeration, which provides an easy way to
	/// access your YAML document.
	///
	/// # Examples
	///
	/// ```
	/// use yaml_rust::Yaml;
	/// let foo = Yaml::from_str("-123"); // convert the string to the appropriate YAML type
	/// assert_eq!(foo.as_i64().unwrap(), -123);
	///
	/// // iterate over an Array
	/// let vec = Yaml::Array(vec![Yaml::Integer(1), Yaml::Integer(2)]);
	/// for v in vec.as_vec().unwrap() {
	/// assert!(v.as_i64().is_some());
	/// }
	/// ```
	#[derive(Clone, PartialEq, PartialOrd, Debug, Eq, Ord, Hash)]
	pub enum Yaml {
	/// Float types are stored as String and parsed on demand.
	/// Note that f64 does NOT implement Eq trait and can NOT be stored in BTreeMap.
	Real(string::String),
	/// YAML int is stored as i64.
	Integer(i64),
	/// YAML scalar.
	String(string::String),
	/// YAML bool, e.g. `true` or `false`.
	Boolean(bool),
	/// YAML array, can be accessed as a `Vec`.
	Array(self::Array),
	/// YAML hash, can be accessed as a `BTreeMap`.
	///
	/// If the order of keys is meaningful, enable the `preserve_order` feature to
	/// store hashes as a `LinkedHashMap` intead of `BTreeMap`. When using a
	/// `LinkedHashMap`, the itertion order will match the order of insertion into
	/// the map.
	///
	/// ```toml
	/// yaml-rust = { version = "*", features = ["preserve_order"] }
	/// ```
	Hash(self::Hash),
	/// Alias, not fully supported yet.
	Alias(usize),
	/// YAML null, e.g. `null` or `~`.
	Null,
	/// Accessing a nonexistent node via the Index trait returns `BadValue`. This
	/// simplifies error handling in the calling code. Invalid type conversion also
	/// returns `BadValue`.
	BadValue,
	}

	pub type Array = Vec<Yaml>;

	#[cfg(not(feature = "preserve_order"))]
	pub type Hash = BTreeMap<Yaml, Yaml>;
	#[cfg(feature = "preserve_order")]
	pub type Hash = ::linked_hash_map::LinkedHashMap<Yaml, Yaml>;

	pub struct YamlLoader {
	docs: Vec<Yaml>,
	// states
	// (current node, anchor_id) tuple
	doc_stack: Vec<(Yaml, usize)>,
	key_stack: Vec<Yaml>,
	anchor_map: BTreeMap<usize, Yaml>,
	}

	impl MarkedEventReceiver for YamlLoader {
	fn on_event(&mut self, ev: &Event, _: Marker) {
	// println!("EV {:?}", ev);
	match *ev {
	Event::DocumentStart => {
	// do nothing
	},
	Event::DocumentEnd => {
	match self.doc_stack.len() {
	// empty document
	0 => self.docs.push(Yaml::BadValue),
	1 => self.docs.push(self.doc_stack.pop().unwrap().0),
	_ => unreachable!()
	}
	},
	Event::SequenceStart(aid) => {
	self.doc_stack.push((Yaml::Array(Vec::new()), aid));
	},
	Event::SequenceEnd => {
	let node = self.doc_stack.pop().unwrap();
	self.insert_new_node(node);
	},
	Event::MappingStart(aid) => {
	self.doc_stack.push((Yaml::Hash(Hash::new()), aid));
	self.key_stack.push(Yaml::BadValue);
	},
	Event::MappingEnd => {
	self.key_stack.pop().unwrap();
	let node = self.doc_stack.pop().unwrap();
	self.insert_new_node(node);
	},
	Event::Scalar(ref v, style, aid, ref tag) => {
	let node = if style != TScalarStyle::Plain {
	Yaml::String(v.clone())
	} else if let Some(TokenType::Tag(ref handle, ref suffix)) = *tag {
	// XXX tag:yaml.org,2002:
	if handle == "!!" {
	match suffix.as_ref() {
	"bool" => {
	// "true" or "false"
	match v.parse::<bool>() {
	Err(_) => Yaml::BadValue,
	Ok(v) => Yaml::Boolean(v)
	}
	},
	"int" => {
	match v.parse::<i64>() {
	Err(_) => Yaml::BadValue,
	Ok(v) => Yaml::Integer(v)
	}
	},
	"float" => {
	match v.parse::<f64>() {
	Err(_) => Yaml::BadValue,
	Ok(_) => Yaml::Real(v.clone())
	}
	},
	"null" => {
	match v.as_ref() {
	"~" \| "null" => Yaml::Null,
	_ => Yaml::BadValue,
	}
	}
	_ => Yaml::String(v.clone()),
	}
	} else {
	Yaml::String(v.clone())
	}
	} else {
	// Datatype is not specified, or unrecognized
	Yaml::from_str(v.as_ref())
	};

	self.insert_new_node((node, aid));
	},
	Event::Alias(id) => {
	let n = match self.anchor_map.get(&id) {
	Some(v) => v.clone(),
	None => Yaml::BadValue,
	};
	self.insert_new_node((n, 0));
	}
	_ => { /* ignore */ }
	}
	// println!("DOC {:?}", self.doc_stack);
	}
	}

	impl YamlLoader {
	fn insert_new_node(&mut self, node: (Yaml, usize)) {
	// valid anchor id starts from 1
	if node.1 > 0 {
	self.anchor_map.insert(node.1, node.0.clone());
	}
	if self.doc_stack.is_empty() {
	self.doc_stack.push(node);
	} else {
	let parent = self.doc_stack.last_mut().unwrap();
	match *parent {
	(Yaml::Array(ref mut v), _) => v.push(node.0),
	(Yaml::Hash(ref mut h), _) => {
	let mut cur_key = self.key_stack.last_mut().unwrap();
	// current node is a key
	if cur_key.is_badvalue() {
	*cur_key = node.0;
	// current node is a value
	} else {
	let mut newkey = Yaml::BadValue;
	mem::swap(&mut newkey, cur_key);
	h.insert(newkey, node.0);
	}
	},
	_ => unreachable!(),
	}
	}
	}

	pub fn load_from_str(source: &str) -> Result<Vec<Yaml>, ScanError>{
	let mut loader = YamlLoader {
	docs: Vec::new(),
	doc_stack: Vec::new(),
	key_stack: Vec::new(),
	anchor_map: BTreeMap::new(),
	};
	let mut parser = Parser::new(source.chars());
	try!(parser.load(&mut loader, true));
	Ok(loader.docs)
	}
	}

	macro_rules! define_as (
	($name:ident, $t:ident, $yt:ident) => (
	pub fn $name(&self) -> Option<$t> {
	match *self {
	Yaml::$yt(v) => Some(v),
	_ => None
	}
	}
	);
	);

	macro_rules! define_as_ref (
	($name:ident, $t:ty, $yt:ident) => (
	pub fn $name(&self) -> Option<$t> {
	match *self {
	Yaml::$yt(ref v) => Some(v),
	_ => None
	}
	}
	);
	);

	macro_rules! define_into (
	($name:ident, $t:ty, $yt:ident) => (
	pub fn $name(self) -> Option<$t> {
	match self {
	Yaml::$yt(v) => Some(v),
	_ => None
	}
	}
	);
	);

	impl Yaml {
	define_as!(as_bool, bool, Boolean);
	define_as!(as_i64, i64, Integer);

	define_as_ref!(as_str, &str, String);
	define_as_ref!(as_hash, &Hash, Hash);
	define_as_ref!(as_vec, &Array, Array);

	define_into!(into_bool, bool, Boolean);
	define_into!(into_i64, i64, Integer);
	define_into!(into_string, String, String);
	define_into!(into_hash, Hash, Hash);
	define_into!(into_vec, Array, Array);

	pub fn is_null(&self) -> bool {
	match *self {
	Yaml::Null => true,
	_ => false
	}
	}

	pub fn is_badvalue(&self) -> bool {
	match *self {
	Yaml::BadValue => true,
	_ => false
	}
	}

	pub fn as_f64(&self) -> Option<f64> {
	match *self {
	Yaml::Real(ref v) => {
	v.parse::<f64>().ok()
	},
	_ => None
	}
	}

	pub fn into_f64(self) -> Option<f64> {
	match self {
	Yaml::Real(v) => {
	v.parse::<f64>().ok()
	},
	_ => None
	}
	}
	}

	#[cfg_attr(feature="clippy", allow(should_implement_trait))]
	impl Yaml {
	// Not implementing FromStr because there is no possibility of Error.
	// This function falls back to Yaml::String if nothing else matches.
	pub fn from_str(v: &str) -> Yaml {
	if v.starts_with("0x") {
	let n = i64::from_str_radix(&v[2..], 16);
	if n.is_ok() {
	return Yaml::Integer(n.unwrap());
	}
	}
	if v.starts_with("0o") {
	let n = i64::from_str_radix(&v[2..], 8);
	if n.is_ok() {
	return Yaml::Integer(n.unwrap());
	}
	}
	if v.starts_with('+') && v[1..].parse::<i64>().is_ok() {
	return Yaml::Integer(v[1..].parse::<i64>().unwrap());
	}
	match v {
	"~" \| "null" => Yaml::Null,
	"true" => Yaml::Boolean(true),
	"false" => Yaml::Boolean(false),
	_ if v.parse::<i64>().is_ok() => Yaml::Integer(v.parse::<i64>().unwrap()),
	// try parsing as f64
	_ if v.parse::<f64>().is_ok() => Yaml::Real(v.to_owned()),
	_ => Yaml::String(v.to_owned())
	}
	}
	}

	static BAD_VALUE: Yaml = Yaml::BadValue;
	impl<'a> Index<&'a str> for Yaml {
	type Output = Yaml;

	fn index(&self, idx: &'a str) -> &Yaml {
	let key = Yaml::String(idx.to_owned());
	match self.as_hash() {
	Some(h) => h.get(&key).unwrap_or(&BAD_VALUE),
	None => &BAD_VALUE
	}
	}
	}

	impl Index<usize> for Yaml {
	type Output = Yaml;

	fn index(&self, idx: usize) -> &Yaml {
	match self.as_vec() {
	Some(v) => v.get(idx).unwrap_or(&BAD_VALUE),
	None => &BAD_VALUE
	}
	}
	}

	impl IntoIterator for Yaml {
	type Item = Yaml;
	type IntoIter = YamlIter;

	fn into_iter(self) -> Self::IntoIter {
	YamlIter {
	yaml: self.into_vec()
	.unwrap_or_else(Vec::new).into_iter()
	}
	}
	}

	pub struct YamlIter {
	yaml: vec::IntoIter<Yaml>,
	}

	impl Iterator for YamlIter {
	type Item = Yaml;

	fn next(&mut self) -> Option<Yaml> {
	self.yaml.next()
	}
	}

	#[cfg(test)]
	mod test {
	use yaml::*;
	#[test]
	fn test_coerce() {
	let s = "---
	a: 1
	b: 2.2
	c: [1, 2]
	";
	let out = YamlLoader::load_from_str(&s).unwrap();
	let doc = &out[0];
	assert_eq!(doc["a"].as_i64().unwrap(), 1i64);
	assert_eq!(doc["b"].as_f64().unwrap(), 2.2f64);
	assert_eq!(doc["c"][1].as_i64().unwrap(), 2i64);
	assert!(doc["d"][0].is_badvalue());
	}

	#[test]
	fn test_empty_doc() {
	let s: String = "".to_owned();
	YamlLoader::load_from_str(&s).unwrap();
	let s: String = "---".to_owned();
	assert_eq!(YamlLoader::load_from_str(&s).unwrap()[0], Yaml::Null);
	}

	#[test]
	fn test_parser() {
	let s: String = "
	# comment
	a0 bb: val
	a1:
	b1: 4
	b2: d
	a2: 4 # i'm comment
	a3: [1, 2, 3]
	a4:
	- - a1
	- a2
	- 2
	a5: 'single_quoted'
	a6: \"double_quoted\"
	a7: 你好
	".to_owned();
	let out = YamlLoader::load_from_str(&s).unwrap();
	let doc = &out[0];
	assert_eq!(doc["a7"].as_str().unwrap(), "你好");
	}

	#[test]
	fn test_multi_doc() {
	let s =
	"
	'a scalar'
	---
	'a scalar'
	---
	'a scalar'
	";
	let out = YamlLoader::load_from_str(&s).unwrap();
	assert_eq!(out.len(), 3);
	}

	#[test]
	fn test_anchor() {
	let s =
	"
	a1: &DEFAULT
	b1: 4
	b2: d
	a2: *DEFAULT
	";
	let out = YamlLoader::load_from_str(&s).unwrap();
	let doc = &out[0];
	assert_eq!(doc["a2"]["b1"].as_i64().unwrap(), 4);
	}

	#[test]
	fn test_bad_anchor() {
	let s =
	"
	a1: &DEFAULT
	b1: 4
	b2: *DEFAULT
	";
	let out = YamlLoader::load_from_str(&s).unwrap();
	let doc = &out[0];
	assert_eq!(doc["a1"]["b2"], Yaml::BadValue);

	}

	#[test]
	fn test_github_27() {
	// https://github.com/chyh1990/yaml-rust/issues/27
	let s = "&a";
	let out = YamlLoader::load_from_str(&s).unwrap();
	let doc = &out[0];
	assert_eq!(doc.as_str().unwrap(), "");
	}

	#[test]
	fn test_plain_datatype() {
	let s =
	"
	- 'string'
	- \"string\"
	- string
	- 123
	- -321
	- 1.23
	- -1e4
	- ~
	- null
	- true
	- false
	- !!str 0
	- !!int 100
	- !!float 2
	- !!null ~
	- !!bool true
	- !!bool false
	- 0xFF
	# bad values
	- !!int string
	- !!float string
	- !!bool null
	- !!null val
	- 0o77
	- [ 0xF, 0xF ]
	- +12345
	- [ true, false ]
	";
	let out = YamlLoader::load_from_str(&s).unwrap();
	let doc = &out[0];

	assert_eq!(doc[0].as_str().unwrap(), "string");
	assert_eq!(doc[1].as_str().unwrap(), "string");
	assert_eq!(doc[2].as_str().unwrap(), "string");
	assert_eq!(doc[3].as_i64().unwrap(), 123);
	assert_eq!(doc[4].as_i64().unwrap(), -321);
	assert_eq!(doc[5].as_f64().unwrap(), 1.23);
	assert_eq!(doc[6].as_f64().unwrap(), -1e4);
	assert!(doc[7].is_null());
	assert!(doc[8].is_null());
	assert_eq!(doc[9].as_bool().unwrap(), true);
	assert_eq!(doc[10].as_bool().unwrap(), false);
	assert_eq!(doc[11].as_str().unwrap(), "0");
	assert_eq!(doc[12].as_i64().unwrap(), 100);
	assert_eq!(doc[13].as_f64().unwrap(), 2.0);
	assert!(doc[14].is_null());
	assert_eq!(doc[15].as_bool().unwrap(), true);
	assert_eq!(doc[16].as_bool().unwrap(), false);
	assert_eq!(doc[17].as_i64().unwrap(), 255);
	assert!(doc[18].is_badvalue());
	assert!(doc[19].is_badvalue());
	assert!(doc[20].is_badvalue());
	assert!(doc[21].is_badvalue());
	assert_eq!(doc[22].as_i64().unwrap(), 63);
	assert_eq!(doc[23][0].as_i64().unwrap(), 15);
	assert_eq!(doc[23][1].as_i64().unwrap(), 15);
	assert_eq!(doc[24].as_i64().unwrap(), 12345);
	assert!(doc[25][0].as_bool().unwrap());
	assert!(!doc[25][1].as_bool().unwrap());
	}

	#[test]
	fn test_bad_hypen() {
	// See: https://github.com/chyh1990/yaml-rust/issues/23
	let s = "{-";
	assert!(YamlLoader::load_from_str(&s).is_err());
	}

	#[test]
	fn test_bad_docstart() {
	assert!(YamlLoader::load_from_str("---This used to cause an infinite loop").is_ok());
	assert_eq!(YamlLoader::load_from_str("----"), Ok(vec![Yaml::String(String::from("----"))]));
	assert_eq!(YamlLoader::load_from_str("--- #here goes a comment"), Ok(vec![Yaml::Null]));
	assert_eq!(YamlLoader::load_from_str("---- #here goes a comment"), Ok(vec![Yaml::String(String::from("----"))]));
	}

	#[test]
	fn test_plain_datatype_with_into_methods() {
	let s =
	"
	- 'string'
	- \"string\"
	- string
	- 123
	- -321
	- 1.23
	- -1e4
	- true
	- false
	- !!str 0
	- !!int 100
	- !!float 2
	- !!bool true
	- !!bool false
	- 0xFF
	- 0o77
	- +12345
	";
	let mut out = YamlLoader::load_from_str(&s).unwrap().into_iter();
	let mut doc = out.next().unwrap().into_iter();

	assert_eq!(doc.next().unwrap().into_string().unwrap(), "string");
	assert_eq!(doc.next().unwrap().into_string().unwrap(), "string");
	assert_eq!(doc.next().unwrap().into_string().unwrap(), "string");
	assert_eq!(doc.next().unwrap().into_i64().unwrap(), 123);
	assert_eq!(doc.next().unwrap().into_i64().unwrap(), -321);
	assert_eq!(doc.next().unwrap().into_f64().unwrap(), 1.23);
	assert_eq!(doc.next().unwrap().into_f64().unwrap(), -1e4);
	assert_eq!(doc.next().unwrap().into_bool().unwrap(), true);
	assert_eq!(doc.next().unwrap().into_bool().unwrap(), false);
	assert_eq!(doc.next().unwrap().into_string().unwrap(), "0");
	assert_eq!(doc.next().unwrap().into_i64().unwrap(), 100);
	assert_eq!(doc.next().unwrap().into_f64().unwrap(), 2.0);
	assert_eq!(doc.next().unwrap().into_bool().unwrap(), true);
	assert_eq!(doc.next().unwrap().into_bool().unwrap(), false);
	assert_eq!(doc.next().unwrap().into_i64().unwrap(), 255);
	assert_eq!(doc.next().unwrap().into_i64().unwrap(), 63);
	assert_eq!(doc.next().unwrap().into_i64().unwrap(), 12345);
	}
	}