library psych
要約
yaml のバックエンドライブラリです。libyaml ベースで作成されてお り、YAML バージョン 1.1 を扱う事ができます。
Overview
Psych is a YAML parser and emitter. Psych leverages libyaml[http://libyaml.org] for it's YAML parsing and emitting capabilities. In addition to wrapping libyaml, Psych also knows how to serialize and de-serialize most Ruby objects to and from the YAML format.
I NEED TO PARSE OR EMIT YAML RIGHT NOW!
# Parse some YAML Psych.load("--- foo") # => "foo" # Emit some YAML Psych.dump("foo") # => "--- foo\n...\n" { :a => 'b'}.to_yaml # => "---\n:a: b\n"
Got more time on your hands? Keep on reading!
YAML Parsing
Psych provides a range of interfaces for parsing a YAML document ranging from low level to high level, depending on your parsing needs. At the lowest level, is an event based parser. Mid level is access to the raw YAML AST, and at the highest level is the ability to unmarshal YAML to ruby objects.
Low level parsing
The lowest level parser should be used when the YAML input is already known, and the developer does not want to pay the price of building an AST or automatic detection and conversion to ruby objects. See Psych::Parser for more information on using the event based parser.
Mid level parsing
Psych provides access to an AST produced from parsing a YAML document. This tree is built using the Psych::Parser and Psych::TreeBuilder. The AST can be examined and manipulated freely. Please see Psych::parse_stream, Psych::Nodes, and Psych::Nodes::Node for more information on dealing with YAML syntax trees.
High level parsing
The high level YAML parser provided by Psych simply takes YAML as input and returns a Ruby data structure. For information on using the high level parser see Psych.load
YAML Emitting
Psych provides a range of interfaces ranging from low to high level for producing YAML documents. Very similar to the YAML parsing interfaces, Psych provides at the lowest level, an event based system, mid-level is building a YAML AST, and the highest level is converting a Ruby object straight to a YAML document.
Low level emitting
The lowest level emitter is an event based system. Events are sent to a Psych::Emitter object. That object knows how to convert the events to a YAML document. This interface should be used when document format is known in advance or speed is a concern. See Psych::Emitter for more information.
Mid level emitting
At the mid level is building an AST. This AST is exactly the same as the AST used when parsing a YAML document. Users can build an AST by hand and the AST knows how to emit itself as a YAML document. See Psych::Nodes, Psych::Nodes::Node, and Psych::TreeBuilder for more information on building a YAML AST.
High level emitting
The high level emitter has the easiest interface. Psych simply takes a Ruby data structure and converts it to a YAML document. See Psych.dump for more information on dumping a Ruby data structure.
クラス
class Psych::Coder | If an object defines +encode_with+, then an instance of Psych::Coder will be passed to the method when the object is being serialized. The Coder automatically assumes a Psych::Nodes::Mapping is being emitted. Other objects like Sequence and Scalar may be emitted if +seq=+ or +scalar=+ are called, respectively. |
class Psych::Handler |
class Psych::Emitter | class Psych::TreeBuilder | This class works in conjunction with Psych::Parser to build an in-memory parse tree that represents a YAML document. |
class Psych::JSON::TreeBuilder | Psych::JSON::TreeBuilder is an event based AST builder. Events are sent to an instance of Psych::JSON::TreeBuilder and a JSON AST is constructed. |
class Psych::Nodes::Node |
class Psych::Nodes::Alias | This class represents a {YAML Alias}[http://yaml.org/spec/1.1/#alias]. It points to an +anchor+. |
class Psych::Nodes::Document | class Psych::Nodes::Mapping | class Psych::Nodes::Scalar | class Psych::Nodes::Sequence | class Psych::Nodes::Stream | class Psych::Parser | class Psych::ScalarScanner | Scan scalars for built in types |
class Psych::Visitors::Visitor |
class Psych::Visitors::DepthFirst | class Psych::Visitors::Emitter | class Psych::Visitors::ToRuby | This class walks a YAML AST, converting each node to ruby |
class Psych::Visitors::YAMLTree | YAMLTree builds a YAML ast given a ruby object. For example: |
class Psych::Stream | Psych::Stream is a streaming YAML emitter. It will not buffer your YAML, but send it straight to an IO. |
class Psych::Visitors::JSONTree |
class Psych::JSON::Stream | class Psych::Omap | class Psych::Set | class Psych::Parser::Mark |
モジュール
module Psych | yaml のバックエンドのためのモジュールです。 |
module Psych::JSON | module Psych::Nodes | When using Psych.load to deserialize a YAML document, the document is translated to an intermediary AST. That intermediary AST is then translated in to a Ruby object graph. |
module Psych::Streaming |
例外クラス
class Psych::Exception |
同時にrequireされるライブラリ
date | 日付をあつかうためのライブラリです。 |
psych/coder | |
psych/core_ext | |
psych/deprecated | |
psych/handler | Psych::Handler is an abstract base class that defines the events used when dealing with Psych::Parser. Clients who want to use Psych::Parser should implement a class that inherits from Psych::Handler and define events that they can handle. |
psych/json | |
psych/json/stream | |
psych/json/tree_builder | |
psych/nodes | |
psych/nodes/alias | |
psych/nodes/document | |
psych/nodes/mapping | |
psych/nodes/node | |
psych/nodes/scalar | |
psych/nodes/sequence | |
psych/nodes/stream | |
psych/omap | |
psych/parser | YAML event parser class. This class parses a YAML document and calls events on the handler that is passed to the constructor. The events can be used for things such as constructing a YAML AST or deserializing YAML documents. It can even be fed back to Psych::Emitter to emit the same document that was parsed. |
psych/scalar_scanner | |
psych/set | |
psych/stream | |
psych/streaming | |
psych/tree_builder | |
psych/visitors | |
psych/visitors/depth_first | |
psych/visitors/emitter | |
psych/visitors/json_tree | |
psych/visitors/to_ruby | |
psych/visitors/visitor | |
psych/visitors/yaml_tree | |
stringio | 文字列に IO と同じインタフェースを持たせるためのライブラリです。 |
strscan | strscan は 文字列を高速にスキャンするためのライブラリです。 |