cowan

127.11.51.1

IntegerSetsCowan

0

{{{ #!html <h2 id="Integersetprocedures">Integer set procedures</h2><p> The elements of an integer set are non-negative exact integers less than the set's <em>limit</em>, which is specified instead of a comparator when it is created. The procedures for creating and manipulating integer sets are the same as those for <a href="http://srfi.schemers.org/srfi-113/srfi-113.html">SRFI 113 sets</a>, except that <code>set</code> is replaced by <code>integer-set</code> in their names, that <code>set-comparator</code> is replaced by <code>integer-set-limit</code>, and that in <code>integer-set</code>, <code>integer-set-unfold</code>, <code>integer-set-map</code>, and <code>integer-set-copy</code> the <em>comparator</em> argument is replaced by a <em>limit</em> argument, a non-negative integer.</p> <p>Wherever a newly allocated integer set is returned by any other procedure, it has the same limit as the source sets. It is an error for a single procedure to be invoked on integer sets with different limits.</p> <p>Although sets subsume integer sets, providing them separately allows for increased implementation efficiency. There are two Chicken eggs that provide integer sets: <a href="http://wiki.call-cc.org/eggref/4/iset#integer-sets"><code>iset</code></a>, which is conceptually similar to the integer sets described here; and <a href="http://wiki.call-cc.org/eggref/4/cis"><code>cis</code></a>, which uses lists of integer intervals.</p> <h3 id="Additionalintegersetprocedures">Additional integer set procedures</h3> <p><code>(integer-set-limit </code><em>integer-set</em><code>)</code></p> <p>Returns the limit of <em>integer-set</em>. This procedure corresponds to <code>set-comparator</code>.</p> <p><code>(universal-integer-set </code><em>limit</em><code>)</code></p><p> Returns a newly allocated integer set. The possible elements of the set are the exact integers from 0 to <em>limit</em> - 1, where <em>limit</em> is an exact non-negative integer. The set contains all possible elements. </p><p><code>(range->integer-set </code><em>limit low high</em><code>)</code></p><p> Returns a newly allocated integer set. The possible elements of the set are the exact integers from 0 to <em>limit</em> - 1, where <em>limit</em> is an exact non-negative integer. The set contains the elements from <em>low</em> (inclusive) to <em>high</em> (exclusive). </p><p><code>(integer-set-adjoin-range </code><em>integer-set low high</em><code>)</code></p><p> Returns a newly allocated integer set with the same limit as <em>integer-set</em> and that contains all its values, and in addition each integer from <em>low</em> (inclusive) to <em>high</em> (exclusive) unless it is already equal to an existing member. </p><p><code>(integer-set-adjoin-range! </code><em>integer-set low high</em><code>)</code></p><p> A linear update procedure that returns an integer set with the same limit as <em>integer-set</em> and that contains all its values, and in addition each integer from <em>low</em> (inclusive) to <em>high</em> (exclusive) unless it is already equal to an existing member. </p><p><code>(integer-set-complement </code><em>integer-set</em><code>)</code></p><p> Returns a newly allocated integer set that is the complement of <em>integer-set</em>. </p><p><code>(integer-set-complement! </code><em>integer-set</em><code>)</code></p><p> A linear update procedure that returns a set that is the complement of <em>integer-set</em>. </p><p><code>(integer-set-min </code><em>integer-set</em><code>)</code></p><p><code>(integer-set-max </code><em>integer-set</em><code>)</code></p><p> Returns the smallest or largest integer in <i>integer-set</i>, or <code>#f</code> if there is none. </p><p><code>(integer-set-delete-min! </code><em>integer-set</em><code>)</code></p> <p><code>(integer-set-delete-max! </code><em>integer-set</em><code>)</code></p><p> Linear update procedures that return two values: the smallest or largest integer in <em>integer-set</em> or <code>#f</code> if there is none, and a set which contains all the elements of <em>set</em> except the integer being returned. </p> }}}

2014-08-15 02:47:57

1