Sophie: sbcl-1.0.31-1mdv2010.0 i586

sbcl-1.0.31-1mdv2010.0.i586.rpm

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<h3 class="section">10.1 Bivalent Streams</h3>

<p>A <dfn>bivalent stream</dfn> can be used to read and write both
<code>character</code> and <code>(unsigned-byte 8)</code> values.  A bivalent
stream is created by calling <code>open</code> with the argument <code>:element-type
:default</code>.  On such a stream, both binary and character data can be
read and written with the usual input and output functions.

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Streams are <em>not</em> created bivalent by default for performance
reasons.  Bivalent streams are incompatible with
<code>fast-read-char</code>, an internal optimization in sbcl's stream
machinery that bulk-converts octets to characters and implements a
fast path through <code>read-char</code>. 
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