FORTRAN Reference Manual

Converting Programs to HP FORTRAN
FORTRAN Reference Manual—528615-001
C-6
HP FORTRAN supports the ANSI FORTRAN 77 form but not the obsolete
extension. If you encounter such statements in programs you are converting,
change them as shown above.
•
Converting programs that read blocked tapes
If a program you are converting reads blocked tapes, you can either cause the
tapes to be copied to an unblocked file for use by a HP FORTRAN program, or
change the FORTRAN program to do its own unblocking of the tape records.
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Hollerith constant syntax
Some FORTRAN implementations allow Hollerith constants with single and double
quotation mark characters (' and ") as delimiters, as well as the nHcc...c notation
specified in an appendix to the ANSI FORTRAN 77 standard. HP FORTRAN
follows that appendix.
HP FORTRAN diagnoses all uses of the " character, but the ' character looks like a
character (not Hollerith) constant, so you will get an error message only if such a
constant is used in a way that is not allowed for character constants. Replace all
such Hollerith constants with the ANSI notation.
•
Using Hollerith constants
Some FORTRAN implementations allow Hollerith constants anywhere that integer,
real, and double precision constants are allowed. HP FORTRAN follows the
appendix to the ANSI FORTRAN 77 standard that restricts Hollerith constants to
DATA and CALL statements.
Programs that use Hollerith constants outside of DATA and CALL statements might
be difficult to convert to HP FORTRAN. You must find all the Hollerith constants not
used in DATA and CALL statements, change them to character constants, and
change the declarations of all non-character variables used with them to type
character of the appropriate length. This change, however, might cause syntax
errors because other non-character variables are also used with those variables.
You might have to make many passes through the program, changing more
variables to type character, until you can compile your program without syntax
errors.