struct JSON::Any

Overview

JSON::Any is a convenient wrapper around all possible JSON types (JSON::Any::Type) and can be used for traversing dynamic or unknown JSON structures.

require "json"

obj = JSON.parse(%({"access": [{"name": "mapping", "speed": "fast"}, {"name": "any", "speed": "slow"}]}))
obj["access"][1]["name"].as_s  # => "any"
obj["access"][1]["speed"].as_s # => "slow"

Note that methods used to traverse a JSON structure, #[] and #[]?, always return a JSON::Any to allow further traversal. To convert them to String, Int32, etc., use the as_ methods, such as #as_s, #as_i, which perform a type check against the raw underlying value. This means that invoking #as_s when the underlying value is not a String will raise: the value won't automatically be converted (parsed) to a String.

Defined in:

json/any.cr

Constructors

Instance Method Summary

Instance methods inherited from struct Struct

==(other) : Bool ==, hash(hasher) hash, inspect(io : IO) : Nil inspect, pretty_print(pp) : Nil pretty_print, to_s(io : IO) : Nil to_s

Instance methods inherited from struct Value

==(other : JSON::Any)
==(other : YAML::Any)
==(other)
==
, dup dup

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(raw : Type) #

Creates a JSON::Any that wraps the given value.


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def self.new(pull : JSON::PullParser) #

Reads a JSON::Any value from the given pull parser.


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Instance Method Detail

def ==(other) #

Returns true if the raw object is equal to other.


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def ==(other : JSON::Any) #

Returns true if both self and other's raw object are equal.


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def [](index : Int) : JSON::Any #

Assumes the underlying value is an Array and returns the element at the given index. Raises if the underlying value is not an Array.


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def [](key : String) : JSON::Any #

Assumes the underlying value is a Hash and returns the element with the given key. Raises if the underlying value is not a Hash.


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def []?(index : Int) : JSON::Any? #

Assumes the underlying value is an Array and returns the element at the given index, or nil if out of bounds. Raises if the underlying value is not an Array.


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def []?(key : String) : JSON::Any? #

Assumes the underlying value is a Hash and returns the element with the given key, or nil if the key is not present. Raises if the underlying value is not a Hash.


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def as_a : Array(Any) #

Checks that the underlying value is Array, and returns its value. Raises otherwise.


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def as_a? : Array(Any)? #

Checks that the underlying value is Array, and returns its value. Returns nil otherwise.


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def as_bool : Bool #

Checks that the underlying value is Bool, and returns its value. Raises otherwise.


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def as_bool? : Bool? #

Checks that the underlying value is Bool, and returns its value. Returns nil otherwise.


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def as_f : Float64 #

Checks that the underlying value is Float, and returns its value as an Float64. Raises otherwise.


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def as_f32 : Float32 #

Checks that the underlying value is Float, and returns its value as an Float32. Raises otherwise.


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def as_f32? : Float32? #

Checks that the underlying value is Float, and returns its value as an Float32. Returns nil otherwise.


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def as_f? : Float64? #

Checks that the underlying value is Float, and returns its value as an Float64. Returns nil otherwise.


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def as_h : Hash(String, Any) #

Checks that the underlying value is Hash, and returns its value. Raises otherwise.


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def as_h? : Hash(String, Any)? #

Checks that the underlying value is Hash, and returns its value. Returns nil otherwise.


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def as_i : Int32 #

Checks that the underlying value is Int, and returns its value as an Int32. Raises otherwise.


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def as_i64 : Int64 #

Checks that the underlying value is Int, and returns its value as an Int64. Raises otherwise.


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def as_i64? : Int64? #

Checks that the underlying value is Int, and returns its value as an Int64. Returns nil otherwise.


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def as_i? : Int32? #

Checks that the underlying value is Int, and returns its value as an Int32. Returns nil otherwise.


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def as_nil : Nil #

Checks that the underlying value is Nil, and returns nil. Raises otherwise.


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def as_s : String #

Checks that the underlying value is String, and returns its value. Raises otherwise.


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def as_s? : String? #

Checks that the underlying value is String, and returns its value. Returns nil otherwise.


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def clone #

Returns a new JSON::Any instance with the #raw value #cloneed.


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def dig(key : String | Int, *subkeys) #

Traverses the depth of a structure and returns the value, otherwise raises.


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def dig?(key : String | Int, *subkeys) #

Traverses the depth of a structure and returns the value. Returns nil if not found.


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def dup #

Returns a new JSON::Any instance with the #raw value #duped.


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def hash(hasher) #

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def raw : Type #

Returns the raw underlying value.


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def size : Int #

Assumes the underlying value is an Array or Hash and returns its size. Raises if the underlying value is not an Array or Hash.


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def to_yaml(yaml : YAML::Nodes::Builder) #

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