Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.53 IMPLICIT Statement
Open Watcom FORTRAN 77 supports three forms of the IMPLICIT statement. The second and third
forms are extensions to the FORTRAN 77 language.
2.53.1 Standard IMPLICIT Statement
IMPLICIT type (a [,a] ...) [,type (a [,a] ...)]...
where:
type
a
len
is one of LOGICAL, INTEGER, REAL, DOUBLE PRECISION, COMPLEX or
CHARACTER[*len].
is either a single letter or a range of letters denoted by separating the first letter in the range from
the last letter in the range by a minus sign.
is the length of the character entities and is a positive unsigned integer constant or a positive
integer constant expression enclosed in parentheses. If len is not specified, the length is 1.
2.53.2 Extended IMPLICIT Statement
IMPLICIT type[*len] (a [,a] ...)
[,type[*len] (a [,a] ...)] ...
where:
type
len
is one of LOGICAL, INTEGER, REAL, DOUBLE PRECISION, COMPLEX or
CHARACTER.
is a positive unsigned integer constant or a positive integer constant expression enclosed in
parentheses. If type is CHARACTER then (*) is also allowed. The possible values of len are
as follows:
1. If type is LOGICAL then len can be 1 or 4. The default is 4.
2. If type is INTEGER then len can be 1, 2 or 4. The default is 4.
3. If type is REAL then len can be 4 or 8. The default is 4.
4. If type is DOUBLE PRECISION then len cannot be specified.
5. If type is COMPLEX then len can be 8 or 16. The default is 8.
6. If type is CHARACTER then len can be (*) or any positive integer.
IMPLICIT Statement 89