HP SunSoft Pascal 4.0 Instrukcja Użytkownika Pobierz pdf (Strona 264)

240 Pascal 4.0 User’s Guide

• Division by zero—The divisor is zero, and the dividend is a ﬁnite non-zero

number; or, more generally, an exact inﬁnite result is delivered by an

operation on ﬁnite operands.

• Overﬂow—The correctly rounded result is larger than the largest number in

the required precision.

• Underﬂow—The number is too small, or precision is lost, and no signal

handler is established for underﬂow.

• Inexact—The rounded result of a valid operation is different from the

inﬁnitely precise result. This exception occurs whenever there is untrapped

overﬂow or untrapped underﬂow.

Math Library Exception-Handling Function: matherr()

Some libm functions are speciﬁed to call matherr()when an exception is

detected. You can redeﬁne matherr() by including a function named

matherr() in the program. When an exception occurs, a pointer to the

exception structure, exc, is passed to the user-supplied matherr() function.

This structure, deﬁned in the math_p.h header ﬁle, is as follows:

The element kind is an integer constant that describes the type of exception

that occurred, and is one of the following constants. These constants are

deﬁned in the header ﬁle.

type

exception = record

kind: integer;

name: ^string;

arg1: double;

arg2: double;

retval: double;

end;

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HP SunSoft Pascal 4.0 Instrukcja Użytkownika Strona 264