50 lines
2.5 KiB
HTML
50 lines
2.5 KiB
HTML
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<!DOCTYPE HTML PUBLIC "-//W3O//DTD W3 HTML 2.0//EN">
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<!Converted with LaTeX2HTML 0.6.5 (Tue Nov 15 1994) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds >
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<HEAD>
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<TITLE>21. Streams</TITLE>
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</HEAD>
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<BODY>
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<meta name="description" value=" Streams">
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<meta name="keywords" value="clm">
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<meta name="resource-type" value="document">
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<meta name="distribution" value="global">
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<P>
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<b>Common Lisp the Language, 2nd Edition</b>
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<BR> <HR><A NAME=tex2html3797 HREF="node183.html"><IMG ALIGN=BOTTOM ALT="next" SRC="icons/next_motif.gif"></A> <A NAME=tex2html3795 HREF="clm.html"><IMG ALIGN=BOTTOM ALT="up" SRC="icons/up_motif.gif"></A> <A NAME=tex2html3789 HREF="node181.html"><IMG ALIGN=BOTTOM ALT="previous" SRC="icons/previous_motif.gif"></A> <A NAME=tex2html3799 HREF="node1.html"><IMG ALIGN=BOTTOM ALT="contents" SRC="icons/contents_motif.gif"></A> <A NAME=tex2html3800 HREF="index.html"><IMG ALIGN=BOTTOM ALT="index" SRC="icons/index_motif.gif"></A> <BR>
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<B> Next:</B> <A NAME=tex2html3798 HREF="node183.html"> Standard Streams</A>
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<B>Up:</B> <A NAME=tex2html3796 HREF="clm.html">Common Lisp the Language</A>
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<B> Previous:</B> <A NAME=tex2html3790 HREF="node181.html"> The Top-Level Loop</A>
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<HR> <P>
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<H1><A NAME=SECTION002500000000000000000>21. Streams</A></H1>
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<P>
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<A NAME=STREAM>Streams</A>
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are objects that serve as sources or sinks of data.
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Character streams produce or absorb characters;
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binary streams produce or absorb integers.
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The normal action of a Common Lisp system is to read characters from
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a character input stream, parse the characters as representations
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of Common Lisp data objects, evaluate each object (as a form) as it is read, and
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print representations of the results of
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evaluation to an output character stream.
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<P>
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Typically streams are connected to files or to an interactive terminal.
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Streams, being Lisp objects, serve as the ambassadors of external
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devices by which input/output is accomplished.
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<P>
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A stream, whether a character stream or a binary
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stream, may be input-only, output-only, or bidirectional.
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What operations may be performed on a stream depends on which of
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the six types of stream it is.
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<P>
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<HR>
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<UL>
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<LI> <A NAME=tex2html3801 HREF="node183.html#SECTION002510000000000000000"> Standard Streams</A>
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<LI> <A NAME=tex2html3802 HREF="node184.html#SECTION002520000000000000000"> Creating New Streams</A>
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<LI> <A NAME=tex2html3803 HREF="node185.html#SECTION002530000000000000000"> Operations on Streams</A>
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</UL>
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<HR>
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<P><ADDRESS>
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AI.Repository@cs.cmu.edu
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</ADDRESS>
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</BODY>
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