class YAML::Builder

Overview

A YAML builder generates valid YAML.

A YAML::Error is raised if attempting to generate an invalid YAML (for example, if invoking #end_sequence without a matching #start_sequence)

require "yaml"

string = YAML.build do |yaml|
  yaml.mapping do
    yaml.scalar "foo"
    yaml.sequence do
      yaml.scalar 1
      yaml.scalar 2
    end
    yaml.scalar "bar"
    yaml.mapping do
      yaml.scalar "baz"
      yaml.scalar "qux"
    end
  end
end
string # => "---\nfoo:\n- 1\n- 2\nbar:\n  baz: qux\n"

Defined in:

yaml/builder.cr

Constructors

Instance Method Summary

Instance methods inherited from class Reference

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other)
==
, dup dup, hash(hasher) hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference)
same?(other : Nil)
same?
, to_s(io : IO) : Nil to_s

Constructor methods inherited from class Reference

new new

Instance methods inherited from class Object

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other)
===
, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash
hash(hasher)
hash
, inspect(io : IO) : Nil
inspect : String
inspect
, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO)
to_json
to_json
, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ")
to_pretty_json
, to_s : String
to_s(io : IO) : Nil
to_s
, to_yaml(io : IO)
to_yaml
to_yaml
, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Constructor methods inherited from class Object

from_json(string_or_io, root : String) : self
from_json(string_or_io) : self
from_json
, from_yaml(string_or_io : String | IO) : self from_yaml

Constructor Detail

def self.new(io : IO) #

Creates a YAML::Builder that will write to the given IO.


[View source]
def self.new(io : IO, &) #

Creates a YAML::Builder that will write to the given IO, invokes the block and closes the builder.


[View source]

Instance Method Detail

def alias(anchor : String) : Nil #

Emits an alias to the given anchor.

require "yaml"

yaml = YAML.build do |builder|
  builder.mapping do
    builder.scalar "key"
    builder.alias "example"
  end
end

yaml # => "---\nkey: *example\n"

[View source]
def close #

Closes the builder, freeing up resources.


[View source]
def document(&) #

Starts a document, invokes the block, and then ends it.


[View source]
def end_document #

Ends a document.


[View source]
def end_mapping #

Ends a mapping.


[View source]
def end_sequence #

Ends a sequence.


[View source]
def end_stream #

Ends a YAML stream.


[View source]
def finalize #

[View source]
def flush #

Flushes any pending data to the underlying IO.


[View source]
def mapping(anchor : String? = nil, tag : String? = nil, style : YAML::MappingStyle = YAML::MappingStyle::ANY, &) #

Starts a mapping, invokes the block, and then ends it.


[View source]
def max_nesting : Int32 #

By default the maximum nesting of sequences/amppings is 99. Nesting more than this will result in a YAML::Error. Changing the value of this property allows more/less nesting.


[View source]
def max_nesting=(max_nesting) #

By default the maximum nesting of sequences/amppings is 99. Nesting more than this will result in a YAML::Error. Changing the value of this property allows more/less nesting.


[View source]
def merge(anchor : String) : Nil #

Emits the scalar "<<" followed by an alias to the given anchor.

See YAML Merge.

require "yaml"

yaml = YAML.build do |builder|
  builder.mapping do
    builder.merge "development"
  end
end

yaml # => "---\n<<: *development\n"

[View source]
def scalar(value, anchor : String? = nil, tag : String? = nil, style : YAML::ScalarStyle = YAML::ScalarStyle::ANY) #

Emits a scalar value.


[View source]
def sequence(anchor : String? = nil, tag : String? = nil, style : YAML::SequenceStyle = YAML::SequenceStyle::ANY, &) #

Starts a sequence, invokes the block, and the ends it.


[View source]
def start_document #

Starts a document.


[View source]
def start_mapping(anchor : String? = nil, tag : String? = nil, style : YAML::MappingStyle = YAML::MappingStyle::ANY) #

Starts a mapping.


[View source]
def start_sequence(anchor : String? = nil, tag : String? = nil, style : YAML::SequenceStyle = YAML::SequenceStyle::ANY) #

Starts a sequence.


[View source]
def start_stream #

Starts a YAML stream.


[View source]
def stream(&) #

Starts a YAML stream, invokes the block, and ends it.


[View source]