Create an abstract Any for JSON/YAML

src/any.cr

@@ -0,0 +1,194 @@
+abstract struct Any
+  # Assumes the underlying value is an `Array` or `Hash` and returns its size.
+  # Raises if the underlying value is not an `Array` or `Hash`.
+  def size : Int
+    case object = @raw
+    when Array
+      object.size
+    when Hash
+      object.size
+    else
+      raise "Expected Array or Hash for #size, not #{object.class}"
+    end
+  end
+
+  # Checks that the underlying value is `Array`, and returns its value.
+  # Raises otherwise.
+  def as_a : Array(Any)
+    @raw.as(Array)
+  end
+
+  # Checks that the underlying value is `Array`, and returns its value.
+  # Returns `nil` otherwise.
+  def as_a? : Array(Any)?
+    @raw.as?(Array)
+  end
+
+  # Checks that the underlying value is `Bool`, and returns its value.
+  # Raises otherwise.
+  def as_bool : Bool
+    @raw.as(Bool)
+  end
+
+  # Checks that the underlying value is `Bool`, and returns its value.
+  # Returns `nil` otherwise.
+  def as_bool? : Bool?
+    @raw.as?(Bool)
+  end
+
+  # Checks that the underlying value is `Float64`, and returns its value.
+  # Raises otherwise.
+  def as_f : Float32
+    as_f64.to_f
+  end
+
+  # Checks that the underlying value is `Float64`, and returns its value.
+  # Returns `nil` otherwise.
+  def as_f? : Float32?
+    as_f64?.try &.to_f
+  end
+
+  # Checks that the underlying value is `Float`, and returns its value as an `Float32`.
+  # Raises otherwise.
+  def as_f64 : Float64
+    @raw.as(Float64)
+  end
+
+  # Checks that the underlying value is `Float`, and returns its value as an `Float32`.
+  # Returns `nil` otherwise.
+  def as_f64? : Float64?
+    @raw.as?(Float64)
+  end
+
+  # Checks that the underlying value is `Nil`, and returns `nil`.
+  # Raises otherwise.
+  def as_nil : Nil
+    @raw.as(Nil)
+  end
+
+  # Checks that the underlying value is `String`, and returns its value.
+  # Raises otherwise.
+  def as_s : String
+    @raw.as(String)
+  end
+
+  # Checks that the underlying value is `String`, and returns its value.
+  # Returns `nil` otherwise.
+  def as_s? : String?
+    @raw.as?(String)
+  end
+
+  # Checks that the underlying value is `Int64`, and returns its value as `Int32`.
+  # Raises otherwise.
+  def as_i : Int32
+    @raw.as(Int64).to_i
+  end
+
+  # Checks that the underlying value is `Int64`, and returns its value as `Int32`.
+  # Returns `nil` otherwise.
+  def as_i? : Int32?
+    @raw.as?(Int64).try &.to_i
+  end
+
+  # Checks that the underlying value is `Int64`, and returns its value.
+  # Raises otherwise.
+  def as_i64 : Int64
+    @raw.as(Int64)
+  end
+
+  # Checks that the underlying value is `Int64`, and returns its value.
+  # Returns `nil` otherwise.
+  def as_i64? : Int64?
+    @raw.as?(Int64)
+  end
+
+  # Checks that the underlying value is `Bytes`, and returns its value.
+  # Raises otherwise.
+  def as_bytes : Bytes
+    @raw.as(Bytes)
+  end
+
+  # Checks that the underlying value is `Bytes`, and returns its value.
+  # Returns `nil` otherwise.
+  def as_bytes? : Bytes?
+    @raw.as?(Bytes)
+  end
+
+  # :nodoc:
+  def inspect(io)
+    @raw.inspect(io)
+  end
+
+  # :nodoc:
+  def to_s(io)
+    @raw.to_s(io)
+  end
+
+  # :nodoc:
+  def pretty_print(pp)
+    @raw.pretty_print(pp)
+  end
+
+  # Returns `true` if both `self` and *other*'s raw object are equal.
+  def ==(other : Any)
+    raw == other.raw
+  end
+
+  # Returns `true` if the raw object is equal to *other*.
+  def ==(other)
+    raw == other
+  end
+
+  # See `Object#hash(hasher)`
+  def_hash raw
+
+  # Returns a new Any instance with the `raw` value `dup`ed.
+  def dup
+    Any.new(raw.dup)
+  end
+
+  # Returns a new Any instance with the `raw` value `clone`ed.
+  def clone
+    Any.new(raw.clone)
+  end
+end
+
+macro any_classes(type)
+  class Object
+    def ===(other : {{type.id}}::Any)
+      self === other.raw
+    end
+  end
+
+  struct Value
+    def ==(other : {{type.id}}::Any)
+      self == other.raw
+    end
+  end
+
+  class Reference
+    def ==(other : {{type.id}}::Any)
+      self == other.raw
+    end
+  end
+
+  class Array
+    def ==(other : {{type.id}}::Any)
+      self == other.raw
+    end
+  end
+
+  class Hash
+    def ==(other : {{type.id}}::Any)
+      self == other.raw
+    end
+  end
+
+  class Regex
+    def ===(other : {{type.id}}::Any)
+      value = self === other.raw
+      $~ = $~
+      value
+    end
+  end
+end