Open Watcom FORTRAN 77 Language Reference

FORTRAN Statements
2.49 GUESS Statement
GUESS
[: block-label]
The GUESS statement is an extension to the FORTRAN 77 language. The GUESS statement marks the
beginning of a block of statements for which a certain assumption or hypothesis has been made. This
hypothesis may be tested using logical IF statements in conjunction with QUIT statements. The ADMIT
statement may be used to mark the beginning of an alternate hypothesis. The END GUESS statement is
used to mark the end of a series of GUESS-ADMIT blocks.
Example:
CHARACTER CH
READ *, CH
GUESS
IF( CH .LT. ’a’ )QUIT
IF( CH .GT. ’z’ )QUIT
PRINT *, ’Lower case letter’
ADMIT
IF( CH .LT. ’A’ )QUIT
IF( CH .GT. ’Z’ )QUIT
PRINT *, ’Upper case letter’
ADMIT
IF( CH .LT. ’0’ )QUIT
IF( CH .GT. ’9’ )QUIT
PRINT *, ’Digit’
ADMIT
PRINT *, ’Special character’
END GUESS
END
An optional block label may be specified with the GUESS statement.
For more information, see the chapter entitled "Program Structure Control Statements" on page 193.
GUESS Statement 83