Chapter 4. Syntax

29

4.6.2.1. Integers

A binary integer is

0b

or

0B

followed by zero or more of the binary digits

01

.

An octal integer is

0

followed by zero or more of the octal digits (

01234567

).

A decimal integer starts with a non zero digit followed by zero or more digits (

0123456789

).

A hexadecimal integer is

0x

or

0X

followed by one or more hexadecimal digits chosen from

0123456789abcdefABCDEF

.

Integers have the usual values. To denote a negative integer, use the prefix operator

discussed under

expressions (Section 7.2.3 Prefix Operator).

4.6.2.2. Bignums

A bignum has the same syntax and semantics as an integer except that the number (or its negative)

takes more than 32 bits to represent in binary. The distinction is made because in some places integers

are permitted while bignums are not.

4.6.2.3. Flonums

A flonum represents a floating point number. The translation is indirect: a decimal floating point num 

ber from the text is converted by

as

to a generic binary floating point number of more than sufficient

precision. This generic floating point number is converted to a particular computer's floating point

format (or formats) by a portion of

as

specialized to that computer.

A flonum is written by writing (in order)

The digit

0

. (

0

is optional on the HPPA.)

A letter, to tell

as

the rest of the number is a flonum. e is recommended. Case is not important.

On the H8/300, H8/500, Renesas / SuperH SH, and AMD 29K architectures, the letter must be one

of the letters

DFPRSX

(in upper or lower case).

On the ARC, the letter must be one of the letters

DFRS

(in upper or lower case).

On the Intel 960 architecture, the letter must be one of the letters

DFT

(in upper or lower case).

On the HPPA architecture, the letter must be

E

(upper case only).

An optional sign: either

+

or

.

An optional integer part: zero or more decimal digits.

An optional fractional part:

.

followed by zero or more decimal digits.

An optional exponent, consisting of:

An

E

or

e

.

Optional sign: either

+

or

.

One or more decimal digits.

At least one of the integer part or the fractional part must be present. The floating point number has

the usual base 10 value.

as

does all processing using integers. Flonums are computed independently of any floating point

hardware in the computer running

as

.