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160 lines
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Copyright (C) 2024 Tomas Volf
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<title>rnrs arithmetic bitwise (Guile Reference Manual)</title>
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<div class="subsubsection-level-extent" id="rnrs-arithmetic-bitwise">
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Next: <a href="rnrs-syntax_002dcase.html" accesskey="n" rel="next">rnrs syntax-case</a>, Previous: <a href="rnrs-arithmetic-flonums.html" accesskey="p" rel="prev">rnrs arithmetic flonums</a>, Up: <a href="R6RS-Standard-Libraries.html" accesskey="u" rel="up">R6RS Standard Libraries</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
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<h4 class="subsubsection" id="rnrs-arithmetic-bitwise-1"><span>7.6.2.23 rnrs arithmetic bitwise<a class="copiable-link" href="#rnrs-arithmetic-bitwise-1"> ¶</a></span></h4>
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<p>The <code class="code">(rnrs arithmetic bitwise (6))</code> library provides procedures for
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performing bitwise arithmetic operations on the two’s complement
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representations of fixnums.
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</p>
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<p>This library and the procedures it exports share functionality with
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SRFI-60, which provides support for bitwise manipulation of integers
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(see <a class="pxref" href="SRFI_002d60.html">SRFI-60 - Integers as Bits</a>).
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</p>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dnot-1"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-not</strong> <var class="def-var-arguments">ei</var><a class="copiable-link" href="#index-bitwise_002dnot-1"> ¶</a></span></dt>
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<dt class="deffnx def-cmd-deffn" id="index-bitwise_002dand-1"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-and</strong> <var class="def-var-arguments">ei1 ...</var><a class="copiable-link" href="#index-bitwise_002dand-1"> ¶</a></span></dt>
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<dt class="deffnx def-cmd-deffn" id="index-bitwise_002dior-1"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-ior</strong> <var class="def-var-arguments">ei1 ...</var><a class="copiable-link" href="#index-bitwise_002dior-1"> ¶</a></span></dt>
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<dt class="deffnx def-cmd-deffn" id="index-bitwise_002dxor-1"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-xor</strong> <var class="def-var-arguments">ei1 ...</var><a class="copiable-link" href="#index-bitwise_002dxor-1"> ¶</a></span></dt>
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<dd><p>These procedures are identical to the <code class="code">lognot</code>, <code class="code">logand</code>,
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<code class="code">logior</code>, and <code class="code">logxor</code> procedures provided by Guile’s core
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library. See <a class="xref" href="Bitwise-Operations.html">Bitwise Operations</a>, for documentation.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dif-1"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-if</strong> <var class="def-var-arguments">ei1 ei2 ei3</var><a class="copiable-link" href="#index-bitwise_002dif-1"> ¶</a></span></dt>
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<dd><p>Returns the bitwise “if” of its arguments. The bit at position
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<code class="code">i</code> in the return value will be the <code class="code">i</code>th bit from <var class="var">ei2</var>
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if the <code class="code">i</code>th bit of <var class="var">ei1</var> is 1, the <code class="code">i</code>th bit from
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<var class="var">ei3</var>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dbit_002dcount"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-bit-count</strong> <var class="def-var-arguments">ei</var><a class="copiable-link" href="#index-bitwise_002dbit_002dcount"> ¶</a></span></dt>
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<dd><p>Returns the number of 1 bits in the two’s complement representation of
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<var class="var">ei</var>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dlength"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-length</strong> <var class="def-var-arguments">ei</var><a class="copiable-link" href="#index-bitwise_002dlength"> ¶</a></span></dt>
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<dd><p>Returns the number of bits necessary to represent <var class="var">ei</var>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dfirst_002dbit_002dset"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-first-bit-set</strong> <var class="def-var-arguments">ei</var><a class="copiable-link" href="#index-bitwise_002dfirst_002dbit_002dset"> ¶</a></span></dt>
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<dd><p>Returns the index of the least significant 1 bit in the two’s complement
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representation of <var class="var">ei</var>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dbit_002dset_003f"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-bit-set?</strong> <var class="def-var-arguments">ei1 ei2</var><a class="copiable-link" href="#index-bitwise_002dbit_002dset_003f"> ¶</a></span></dt>
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<dd><p>Returns <code class="code">#t</code> if the <var class="var">ei2</var>th bit in the two’s complement
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representation of <var class="var">ei1</var> is 1, <code class="code">#f</code> otherwise.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dcopy_002dbit"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-copy-bit</strong> <var class="def-var-arguments">ei1 ei2 ei3</var><a class="copiable-link" href="#index-bitwise_002dcopy_002dbit"> ¶</a></span></dt>
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<dd><p>Returns the result of setting the <var class="var">ei2</var>th bit of <var class="var">ei1</var> to the
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<var class="var">ei2</var>th bit of <var class="var">ei3</var>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dbit_002dfield"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-bit-field</strong> <var class="def-var-arguments">ei1 ei2 ei3</var><a class="copiable-link" href="#index-bitwise_002dbit_002dfield"> ¶</a></span></dt>
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<dd><p>Returns the integer representation of the contiguous sequence of bits in
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<var class="var">ei1</var> that starts at position <var class="var">ei2</var> (inclusive) and ends at
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position <var class="var">ei3</var> (exclusive).
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dcopy_002dbit_002dfield"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-copy-bit-field</strong> <var class="def-var-arguments">ei1 ei2 ei3 ei4</var><a class="copiable-link" href="#index-bitwise_002dcopy_002dbit_002dfield"> ¶</a></span></dt>
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<dd><p>Returns the result of replacing the bit field in <var class="var">ei1</var> with start
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and end positions <var class="var">ei2</var> and <var class="var">ei3</var> with the corresponding bit
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field from <var class="var">ei4</var>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002darithmetic_002dshift"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-arithmetic-shift</strong> <var class="def-var-arguments">ei1 ei2</var><a class="copiable-link" href="#index-bitwise_002darithmetic_002dshift"> ¶</a></span></dt>
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<dt class="deffnx def-cmd-deffn" id="index-bitwise_002darithmetic_002dshift_002dleft"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-arithmetic-shift-left</strong> <var class="def-var-arguments">ei1 ei2</var><a class="copiable-link" href="#index-bitwise_002darithmetic_002dshift_002dleft"> ¶</a></span></dt>
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<dt class="deffnx def-cmd-deffn" id="index-bitwise_002darithmetic_002dshift_002dright"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-arithmetic-shift-right</strong> <var class="def-var-arguments">ei1 ei2</var><a class="copiable-link" href="#index-bitwise_002darithmetic_002dshift_002dright"> ¶</a></span></dt>
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<dd><p>Returns the result of shifting the bits of <var class="var">ei1</var> right or left by
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the <var class="var">ei2</var> positions. <code class="code">bitwise-arithmetic-shift</code> is identical
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to <code class="code">bitwise-arithmetic-shift-left</code>.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002drotate_002dbit_002dfield"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-rotate-bit-field</strong> <var class="def-var-arguments">ei1 ei2 ei3 ei4</var><a class="copiable-link" href="#index-bitwise_002drotate_002dbit_002dfield"> ¶</a></span></dt>
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<dd><p>Returns the result of cyclically permuting the bit field in <var class="var">ei1</var>
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with start and end positions <var class="var">ei2</var> and <var class="var">ei3</var> by <var class="var">ei4</var> bits
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in the direction of more significant bits.
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</p></dd></dl>
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<dl class="first-deffn">
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<dt class="deffn" id="index-bitwise_002dreverse_002dbit_002dfield"><span class="category-def">Scheme Procedure: </span><span><strong class="def-name">bitwise-reverse-bit-field</strong> <var class="def-var-arguments">ei1 ei2 ei3</var><a class="copiable-link" href="#index-bitwise_002dreverse_002dbit_002dfield"> ¶</a></span></dt>
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<dd><p>Returns the result of reversing the order of the bits of <var class="var">ei1</var>
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between position <var class="var">ei2</var> (inclusive) and position <var class="var">ei3</var>
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(exclusive).
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</p></dd></dl>
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</div>
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<hr>
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<p>
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Next: <a href="rnrs-syntax_002dcase.html">rnrs syntax-case</a>, Previous: <a href="rnrs-arithmetic-flonums.html">rnrs arithmetic flonums</a>, Up: <a href="R6RS-Standard-Libraries.html">R6RS Standard Libraries</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
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