2.2.6 Terminology Referring to Data Items

Individual Fortran statements and expressions can have restrictions in using and formatting data items: constants, variables, arrays, array elements, scalar record fields, aggregate fields, character substrings, and expressions.

Throughout this manual, the following four categories identify which data items can be included in a particular statement or expression:

• Scalar Reference: This resolves into a reference to a single data item having a data type (a variable, scalar record field, array element, constant, character substring, or expression).

• Scalar Memory Reference: This resolves into a data item that can be assigned a value by means of an assignment statement. It is similar to a scalar reference, excluding constants, character substrings, and expressions.

• Array Name Reference: This resolves into a reference to an array.

• Aggregate Reference: This resolves into a reference to a structured data item (a record structure or substructure).

Examples

Consider the following declarations:

INTEGER INT, INTARY (10)
 . . .
STRUCTURE /STRA/
    INTEGER  INTFLD, INTFLDARY (10)
END STRUCTURE

STRUCTURE /STRB/
    CHARACTER*20  CHARFLD
    INTEGER  INTFLD, INTFLDARY (10)
    STRUCTURE STRUCFLD
        COMPLEX  CPXFLD, CPXFLDARY (10)
    END STRUCTURE
    RECORD  /STRA/  RECFLD, RECFLDARY (10)
END STRUCTURE
 . . .
RECORD  /STRB/  REC, RECRUIT (10)

Each of the following references is derived from the preceding data declarations:

Scalar References

INT
INTARY(1)
REC.INTFLD
REC.INTFLDARY(1)
REC.RECFLD.INTFLD
REC.STRUCFLD.CPXFLD
REC.RECFLD.INTFLDARY(1)
REC.RECFLDARY(1).INTFLD
REC.RECFLDARY(1).INTFLDARY(1)
REC.CHARFLD
REC.CHARFLD(5:10)
RECRUIT(1).CHARFLD(5:10)
RECRUIT(1).INTFLD
RECRUIT(1).INTFLDARY(1)
RECRUIT(1).RECFLD.INTFLD
RECRUIT(1).STRUCFLD.CPXFLD

RECRUIT(1).RECFLD.INTFLDARY(1)
RECRUIT(1).RECFLDARY(1).INTFLD
RECRUIT(1).RECFLDARY(1).INTFLDARY(1)

Scalar Memory References

All references listed in the preceding scalar references category are also in the category of scalar memory references, because they do not include constants and expressions.

Array Name References

INTARY
RECRUIT
REC.INTFLDARY
REC.RECFLDARY
REC.RECFLD.INTFLDARY
REC.RECFLDARY(1).INTFLDARY
REC.STRUCFLD.CPXFLDARY
RECRUIT(1).INTFLDARY
RECRUIT(1).RECFLDARY

RECRUIT(1).RECFLD.INTFLDARY
RECRUIT(1).STRUCFLD.CPXFLDARY
RECRUIT(1).RECFLDARY(1).INTFLDARY

REC
RECRUIT(1)

REC.RECFLD
REC.STRUCFLD
REC.RECFLDARY(1)
RECRUIT(1).RECFLD
RECRUIT(1).STRUCFLD
RECRUIT(1).RECFLDARY(1)