TOPS-20 PASCAL Language Manual - Bitsavers

PROCEDURES AND FUNCTIONS
Table ~-2:
Predeclared Functions (Cont.)
Category
Function
Parameter Result
Type Type
Purpose
PRED(a)
SUCC(a)
any
scalar
type
except
a r eaJ
type
any
scaJar
type
except
a real
type
same
type as
parameter
Returns the
predecessor value
in the type of a
(if a predecessor
exists). But it is
up to you to make
sure there is
pred/succ. The
compiJer will
always return with
the next ordinal
value higher/lower
than a. There is
no
bounds
checking. Checking
0ccurs only if the
PRED(a) or SUCC(a)
is in an
ass ignmen t
statement, for
example:
(*$CHE~K+*)
x: =PRED (a)
same Returns the
type as successor value in
parameter the type of a (if
a successor
exists) .
PASCAL also provides additional arithmetic routines available with
PASLIB, the PASCAL library. Use the following format to specify a
routine from the Common Math Library:
where:
reSUl t type;}
FUNCTION routine name (VAR parameter list): { FORTRAN
routine name is one of the names listed in Table ~-3.
parameter list are acceptable arguments for this routine. See
the TOPS-IO/TOPS-20 Common Math Library Reference
Manual.
result type
is the type of the function result.
Table ~-3 lists these routines and their purpose. For more
information concerning these routines, refer to the TOPS-IO/TOPS-20
Common Math Library Reference Manual.
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