UnionConstructor

A union value built from one of its members.

Declaración

Sintaxis

UnionConstructor(symbol dt_sym, expr* args, ttype type, expr? value)

Argumentos

Argument

Descripción

dt_sym

the Union being constructed.

args

the value of the member being set.

type

the UnionType of the result.

value

the compile time value of the expression, when the frontend could fold it; nil otherwise.

Valores devueltos

The value of the expression.

Descripción

Only one member of a union holds a value at a time, so a constructor takes one argument: the member being set.

Ejemplos

(UnionConstructor
  :dt_sym (SymbolRef 3 "word")
  :args [
    (IntegerConstant
      :n 1
      :type (Integer
        :kind 4
      )
      :intboz_type :Decimal
    )
  ]
  :type (UnionType
    :data_member_types [
      (Integer
        :kind 4
      )
      (Real
        :kind 4
      )
    ]
  )
  :value nil
)

It comes from this complete ASR text document:

(TranslationUnit
  :symtab (SymbolTable
    :id 0
    :symbols {
      "m" (Module
        :symtab (SymbolTable
          :id 1
          :symbols {
            "word" (Union
              :symtab (SymbolTable
                :id 2
                :symbols {
                  "i" (Variable
                    :parent_symtab 2
                    :name "i"
                    :dependencies []
                    :intent :Local
                    :symbolic_value nil
                    :value nil
                    :storage :Default
                    :type (Integer
                      :kind 4
                    )
                    :type_declaration nil
                    :abi :Source
                    :access :Public
                    :presence :Required
                    :value_attr false
                    :target_attr false
                    :contiguous_attr false
                    :bindc_name nil
                    :is_volatile false
                    :is_protected false
                    :pass_attr :NotMethod
                    :self_argument nil
                    :codims []
                  )
                  "r" (Variable
                    :parent_symtab 2
                    :name "r"
                    :dependencies []
                    :intent :Local
                    :symbolic_value nil
                    :value nil
                    :storage :Default
                    :type (Real
                      :kind 4
                    )
                    :type_declaration nil
                    :abi :Source
                    :access :Public
                    :presence :Required
                    :value_attr false
                    :target_attr false
                    :contiguous_attr false
                    :bindc_name nil
                    :is_volatile false
                    :is_protected false
                    :pass_attr :NotMethod
                    :self_argument nil
                    :codims []
                  )
                }
              )
              :name "word"
              :dependencies []
              :members [
                "i"
                "r"
              ]
              :abi :Source
              :access :Public
              :initializers []
              :parent nil
            )
          }
        )
        :name "m"
        :parent_module nil
        :dependencies []
        :loaded_from_mod false
        :intrinsic false
        :has_submodules false
      )
      "main" (Program
        :symtab (SymbolTable
          :id 3
          :symbols {
            "i" (Variable
              :parent_symtab 3
              :name "i"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "w" (Variable
              :parent_symtab 3
              :name "w"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (UnionType
                :data_member_types [
                  (Integer
                    :kind 4
                  )
                  (Real
                    :kind 4
                  )
                ]
              )
              :type_declaration (SymbolRef 3 "word")
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "word" (ExternalSymbol
              :parent_symtab 3
              :name "word"
              :external (SymbolRef 1 "word")
              :module_name "m"
              :scope_names []
              :original_name "word"
              :access :Public
            )
          }
        )
        :name "main"
        :dependencies [
          "m"
        ]
        :body [
          (Assignment
            :target (Var
              :v (SymbolRef 3 "w")
            )
            :value (UnionConstructor
              :dt_sym (SymbolRef 3 "word")
              :args [
                (IntegerConstant
                  :n 1
                  :type (Integer
                    :kind 4
                  )
                  :intboz_type :Decimal
                )
              ]
              :type (UnionType
                :data_member_types [
                  (Integer
                    :kind 4
                  )
                  (Real
                    :kind 4
                  )
                ]
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 3 "i")
            )
            :value (UnionInstanceMember
              :v (Var
                :v (SymbolRef 3 "w")
              )
              :m (SymbolRef 2 "i")
              :type (Integer
                :kind 4
              )
              :value nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
        ]
      )
    }
  )
  :items []
)

Ver también

Union, UnionInstanceMember, UnionType