inexact -- r7rs Definition

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Kind

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converter;

Implemented by

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• inexact (from vonuvoli);

Procedure signature

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Procedure variants:

• ((number) -> (inexact-number))
  • input: a value of type number;
  • output: a value of type inexact-number;

Exports

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• scheme:complex -- (scheme complex);

Exports recursive

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• scheme -- (scheme);

Description

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(inexact z)
(exact z)

The procedure inexact returns an inexact representation of z. The value returned is the inexact number that is numerically closest to the argument. For inexact arguments, the result is the same as the argument. For exact complex numbers, the result is a complex number whose real and imaginary parts are the result of applying inexact to the real and imaginary parts of the argument, respectively. If an exact argument has no reasonably close inexact equivalent (in the sense of =), then a violation of an implementation restriction may be reported.

The procedure exact returns an exact representation of z. The value returned is the exact number that is numerically closest to the argument. For exact arguments, the result is the same as the argument. For inexact non-integral real arguments, the implementation may return a rational approximation, or may report an implementation violation. For inexact complex arguments, the result is a complex number whose real and imaginary parts are the result of applying exact to the real and imaginary parts of the argument, respectively. If an inexact argument has no reasonably close exact equivalent, (in the sense of =), then a violation of an implementation restriction may be reported.

These procedures implement the natural one-to-one correspondence between exact and inexact integers throughout an implementation-dependent range. See section on restrictions.

Note: These procedures were known in R5RS as exact->inexact and inexact->exact, respectively, but they have always accepted arguments of any exactness. The new names are clearer and shorter, as well as being compatible with R6RS.

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The text herein was sourced and adapted as described in the "R7RS attribution of various text snippets" appendix.

Referenced-types

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• number;
• inexact-number;