DOC HOME SITE MAP MAN PAGES GNU INFO SEARCH PRINT BOOK

# (r5rs.info.gz) Syntax of numerical constants

Info Catalog (r5rs.info.gz) Implementation restrictions (r5rs.info.gz) Numbers (r5rs.info.gz) Numerical operations
```
6.2.4 Syntax of numerical constants
-----------------------------------

The syntax of the written representations for numbers is described
formally in section  Lexical structure.  Note that case is not
significant in numerical constants.

A number may be written in binary, octal, decimal, or hexadecimal by
the use of a radix prefix.  The radix prefixes are `#b' (binary), `#o'
a number is assumed to be expressed in decimal.

A numerical constant may be specified to be either exact or inexact by
a prefix.  The prefixes are `#e' for exact, and `#i' for inexact.  An
exactness prefix may appear before or after any radix prefix that is
used.  If the written representation of a number has no exactness
prefix, the constant may be either inexact or exact.  It is inexact if
it contains a decimal point, an exponent, or a "#" character in the
place of a digit, otherwise it is exact.

In systems with inexact numbers of varying precisions it may be useful
to specify the precision of a constant.  For this purpose, numerical
constants may be written with an exponent marker that indicates the
desired precision of the inexact representation.  The letters `s', `f',
`d', and `l' specify the use of SHORT, SINGLE, DOUBLE, and LONG
precision, respectively.  (When fewer than four internal inexact
representations exist, the four size specifications are mapped onto
those available.  For example, an implementation with two internal
representations may map short and single together and long and double
together.)  In addition, the exponent marker `e' specifies the default
precision for the implementation.  The default precision has at least
as much precision as DOUBLE, but implementations may wish to allow this
default to be set by the user.

3.14159265358979F0
Round to single -- 3.141593
0.6L0
Extend to long -- .600000000000000

```
Info Catalog (r5rs.info.gz) Implementation restrictions (r5rs.info.gz) Numbers (r5rs.info.gz) Numerical operations
automatically generated byinfo2html