Intrinsic Procedures

 

We have already met most of the new intrinsic functions  in previous parts of this series. Here, we deal only with their general classification and with those that have so far been omitted.

All intrinsic procedures can be referenced using keyword  arguments:

  CALL DATE_AND_TIME (TIME=t)

and many have optional  arguments. They are grouped into four categories:

1. elemental - work on scalars or arrays, e.g. ABS(a);
2. inquiry - independent of value of argument (which maybe undefined), e.g. PRECISION(a);
3. transformational - array argument with array result of different shape, e.g. RESHAPE(a, b);
4. subroutines, e.g. SYSTEM_CLOCK.

The procedures not already introduced are:

• Bit inquiry 

    BIT_SIZE           Number of bits in the model
  

• Bit manipulation 

    BTEST              Bit testing
    IAND               Logical AND
    IBCLR              Clear bit
    IBITS              Bit extraction
    IBSET              Set bit
    IEOR               Exclusive OR
    IOR                Inclusive OR
    ISHFT              Logical shift
    ISHFTC             Circular shift
    NOT                Logical complement
  

• Transfer function, as in

    INTEGER :: i = TRANSFER('abcd', 0) ! replaces part of EQUIVALENCE
  

• Subroutines

    DATE_AND_TIME      Obtain date and/or time
    MVBITS             Copies bits
    RANDOM_NUMBER      Returns pseudorandom numbers
    RANDOM_SEED        Access to seed
    SYSTEM_CLOCK       Access to system clock