cast_kind

Which conversion a Cast performs.

Declaration

Syntax

cast_kind
    = RealToInteger
    | IntegerToReal
    | LogicalToReal
    | RealToReal
    | IntegerToInteger
    | RealToComplex
    | IntegerToComplex
    | IntegerToLogical
    | RealToLogical
    | StringToLogical
    | StringToInteger
    | StringToList
    | ComplexToLogical
    | ComplexToComplex
    | ComplexToReal
    | ComplexToInteger
    | LogicalToInteger
    | LogicalToLogical
    | RealToString
    | IntegerToString
    | LogicalToString
    | StringToString
    | UnsignedIntegerToInteger
    | UnsignedIntegerToUnsignedInteger
    | UnsignedIntegerToReal
    | UnsignedIntegerToLogical
    | IntegerToUnsignedInteger
    | RealToUnsignedInteger
    | CPtrToUnsignedInteger
    | UnsignedIntegerToCPtr
    | IntegerToSymbolicExpression
    | ListToArray
    | StringToArray
    | PointerToInteger
    | ClassToStruct
    | ClassToClass
    | ClassToIntrinsic

Values

Value	Meaning
RealToInteger	truncates towards zero.
IntegerToReal	exact for values the real type can represent.
LogicalToReal	false becomes 0.0, true becomes 1.0.
RealToReal	changes the real kind, rounding when it narrows.
IntegerToInteger	changes the integer kind, wrapping when it narrows.
RealToComplex	the value becomes the real part; the imaginary part is zero.
IntegerToComplex	the value becomes the real part.
IntegerToLogical	zero becomes false, anything else true.
RealToLogical	zero becomes false, anything else true.
StringToLogical	an LPython conversion: the empty string is false.
StringToInteger	parses the string as an integer.
StringToList	an LPython conversion to a list of characters.
ComplexToLogical	zero becomes false.
ComplexToComplex	changes the complex kind.
ComplexToReal	takes the real part.
ComplexToInteger	takes the real part and truncates it.
LogicalToInteger	false becomes 0, true becomes 1.
LogicalToLogical	changes the logical kind.
RealToString	formats the value.
IntegerToString	formats the value.
LogicalToString	formats the value.
StringToString	changes the string kind.
UnsignedIntegerToInteger	reinterprets the value as signed.
UnsignedIntegerToUnsignedInteger	changes the unsigned kind.
UnsignedIntegerToReal	exact for values the real type can represent.
UnsignedIntegerToLogical	zero becomes false.
IntegerToUnsignedInteger	reinterprets the value as unsigned.
RealToUnsignedInteger	truncates towards zero.
CPtrToUnsignedInteger	the address as a number.
UnsignedIntegerToCPtr	a number as an address.
IntegerToSymbolicExpression	wraps an integer as a symbolic expression.
ListToArray	an LPython conversion from a list to an array.
StringToArray	a string as an array of characters.
PointerToInteger	the address as a number.
ClassToStruct	narrows a polymorphic value to a derived type.
ClassToClass	changes which class a polymorphic value is described as.
ClassToIntrinsic	narrows a polymorphic value to an intrinsic type.

Return values

None. An enumeration value is not evaluated.

Description

Every implicit conversion is explicit in ASR, and this enumeration says which conversion a Cast performs. The kind and the type of the Cast agree: the kind names the pair of types, and the type is the result.

Conversions that do not change the bits belong to ArrayPhysicalCast and StringPhysicalCast instead.

Examples

(Cast
  :arg (Var
    :v (SymbolRef 1 "i")
  )
  :kind :IntegerToReal
  :type (Real
    :kind 8
  )
  :value nil
  :dest nil
)

It comes from this complete ASR text document:

(TranslationUnit
  :symtab (SymbolTable
    :id 0
    :symbols {
      "main" (Program
        :symtab (SymbolTable
          :id 1
          :symbols {
            "i" (Variable
              :parent_symtab 1
              :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 []
            )
            "x" (Variable
              :parent_symtab 1
              :name "x"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Real
                :kind 8
              )
              :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 "main"
        :dependencies []
        :body [
          (Assignment
            :target (Var
              :v (SymbolRef 1 "x")
            )
            :value (Cast
              :arg (Var
                :v (SymbolRef 1 "i")
              )
              :kind :IntegerToReal
              :type (Real
                :kind 8
              )
              :value nil
              :dest nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
          (Assignment
            :target (Var
              :v (SymbolRef 1 "i")
            )
            :value (Cast
              :arg (Var
                :v (SymbolRef 1 "x")
              )
              :kind :RealToInteger
              :type (Integer
                :kind 4
              )
              :value nil
              :dest nil
            )
            :overloaded nil
            :realloc_lhs false
            :move_allocation false
          )
        ]
      )
    }
  )
  :items []
)

See Also

Cast, Integer, Real, ArrayPhysicalCast, StringPhysicalCast