HP 3000 Manuals HP 3000 Manuals
FORTRAN and Pascal Data Types
When a FORTRAN program interfaces with a Pascal program unit, be aware of
the corresponding data types shown in table 8-1. In particular, note the
differences between character strings and Boolean variables between the
two languages.
Table 8-1. HP FORTRAN 77 and HP Pascal Data Types
-------------------------------------------------------------------------------
| | |
| HP FORTRAN 77 Type | HP Pascal Type |
| | |
-------------------------------------------------------------------------------
| | |
| INTEGER*4 | INTEGER or integer subrange beyond the range |
| | 0 .. 65535 |
| | |
-------------------------------------------------------------------------------
| | |
| INTEGER*2 | SHORTINT or integer subrange inside the range |
| | 0 .. 65535 |
| | |
-------------------------------------------------------------------------------
| | |
| REAL*4 | REAL |
| | |
-------------------------------------------------------------------------------
| | |
| REAL*8 | LONGREAL |
| | |
-------------------------------------------------------------------------------
| | |
| BYTE, | Integer subrange inside the range 0..255 |
| LOGICAL*1 | |
| | |
-------------------------------------------------------------------------------
| | |
| CHARACTER | CHAR |
| | |
-------------------------------------------------------------------------------
| | |
| CHARACTER*n | PACKED ARRAY [1..n] OF CHAR |
| | |
-------------------------------------------------------------------------------
| | |
| LOGICAL*4 | INTEGER or |
| | SET (4 bytes) |
| | |
-------------------------------------------------------------------------------
| | |
| LOGICAL*2 | Integer subrange inside the range 0..65535 or |
| | SET (2 bytes) |
| | |
-------------------------------------------------------------------------------
| | |
| COMPLEX*8 | RECORD |
| | real_part : REAL; |
| | imag_part : REAL; |
| | END; |
| | |
-------------------------------------------------------------------------------
| | |
| COMPLEX*16 | RECORD |
| | real_part : LONGREAL; |
| | imag_part : LONGREAL; |
| | END; |
| | |
-------------------------------------------------------------------------------
| | |
| REAL*16 | No corresponding Pascal data type. |
| | |
-------------------------------------------------------------------------------
HP FORTRAN 77 has a one-word descriptor that describes the maximum length
of the string while PACs (PACKED ARRAY[1..n] OF CHAR) in Pascal do not.
Therefore, when you pass a character string to a Pascal string, Pascal
expects a pointer to that string only.
Boolean variables also differ between the two languages. Pascal Boolean
variables are one-byte variables, while FORTRAN logical variables are two
or four bytes (LOGICAL*2 or LOGICAL*4).
Also note the following when a FORTRAN program interfaces with a Pascal
program unit:
* HP FORTRAN 77 cannot pass arrays by value, so you cannot call a
Pascal routine with a value parameter of a type corresponding to
an HP FORTRAN 77 array type.
* All data must be passed through the parameter lists because HP
FORTRAN 77 cannot specify global variables and Pascal cannot
specify COMMON blocks.
* HP FORTRAN 77 expects parameters to be passed by reference, with
the exception of the maximum length of a character string, as
described earlier.
* Parameter type checking should be turned off because HP FORTRAN 77
generates different types of check values from Pascal.
* Files and labels cannot be passed between HP FORTRAN 77 and
Pascal.