Open Watcom FORTRAN 77 Language Reference

Language Reference
7.1.3 Arithmetic Constant Expression
An arithmetic constant expression is an arithmetic expression in which all primaries are one of the
following.
1. arithmetic constant
2. symbolic arithmetic constant
3. ( arithmetic constant expression )
There is a further restriction with the exponentiation operator; the exponent must be of type INTEGER.
As an extension to the FORTRAN 77 language, Open Watcom FORTRAN 77 supports the use of the
intrinsic function ISIZEOF in an arithmetic constant expression.
Example:
PARAMETER (INTSIZ = ISIZEOF(INTEGER))
An integer constant expression is an arithmetic constant expression in which all constants and symbolic
constants are of type INTEGER.
Example:
123
-753+2
-(12*13)
A real constant expression is an arithmetic constant expression in which at least one constant or symbolic
constant is of type REAL and all other constants or symbolic constants are of type REAL or INTEGER.
Example:
123.
-753+2.0
-(13E0*12)
A double precision constant expression is an arithmetic constant expression in which at least one constant
or symbolic constant is of type DOUBLE PRECISION and all other constants or symbolic constants are of
type DOUBLE PRECISION, REAL or INTEGER.
Example:
123.4D0
-753D0*2+.5
-(12D0*12.2)
A complex constant expression is an arithmetic constant expression in which at least one constant or
symbolic constant is of type COMPLEX and all other constants or symbolic constants are of type
COMPLEX, REAL or INTEGER.
176 Arithmetic Expressions