txlyre
/
avram


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137
							<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd">
<html>
<!-- Created on November 8, 2012 by texi2html 1.82
texi2html was written by: 
            Lionel Cons <[email protected]> (original author)
            Karl Berry  <[email protected]>
            Olaf Bachmann <[email protected]>
            and many others.
Maintained by: Many creative people.
Send bugs and suggestions to <[email protected]>
-->
<head>
<title>avram - a virtual machine code interpreter: 2.5.1.2 Standard Output Representation</title>

<meta name="description" content="avram - a virtual machine code interpreter: 2.5.1.2 Standard Output Representation">
<meta name="keywords" content="avram - a virtual machine code interpreter: 2.5.1.2 Standard Output Representation">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="texi2html 1.82">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
pre.display {font-family: serif}
pre.format {font-family: serif}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: serif; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: serif; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.roman {font-family:serif; font-weight:normal;}
span.sansserif {font-family:sans-serif; font-weight:normal;}
ul.toc {list-style: none}
-->
</style>


</head>

<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">

<a name="Standard-Output-Representation"></a>
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="Standard-Input-Representation.html#Standard-Input-Representation" title="Previous section in reading order"> &lt; </a>]</td>
<td valign="middle" align="left">[<a href="Line-Maps.html#Line-Maps" title="Next section in reading order"> &gt; </a>]</td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left">[<a href="Virtual-Machine-Specification.html#Virtual-Machine-Specification" title="Beginning of this chapter or previous chapter"> &lt;&lt; </a>]</td>
<td valign="middle" align="left">[<a href="Loading-All-of-Standard-Input-at-Once.html#Loading-All-of-Standard-Input-at-Once" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="Library-Reference.html#Library-Reference" title="Next chapter"> &gt;&gt; </a>]</td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left">[<a href="avram.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="avram_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Function-Index.html#Function-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="avram_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<hr size="1">
<a name="Standard-Output-Representation-1"></a>
<h4 class="subsubsection">2.5.1.2 Standard Output Representation</h4>

<a name="index-standard-output"></a>
<a name="index-raw_002doutput-command-line-option-1"></a>
<a name="index-choice_002dof_002doutput-command-line-option-2"></a>
<p>As in the case of standard input, the representation for standard output
that the function is expected to return depends on the command line
options with which the application is invoked. The only relevant options
are &lsquo;<samp>--raw-output</samp>&rsquo; and &lsquo;<samp>--choice-of-output</samp>&rsquo;, which are
mutually exclusive.
</p>
<ul>
<li> If neither option is selected, the result returned by the function must
be a list of character strings. 
</li><li> If &lsquo;<samp>--raw-output</samp>&rsquo; is used, the result returned by the
function is unconstrained, and it will be written as a data file with no
preamble, following the format specified in <a href="File-Format.html#File-Format">File Format</a>.
</li><li> If &lsquo;<samp>--choice-of-output</samp>&rsquo; is used, the result returned by the
function must be a pair <code>(<var>preamble</var>,<var>contents</var>)</code>.
</li></ul>

<a name="index-preamble-2"></a>
<p>In the last case, the preamble determines how the file will be written.
If it is meant to be a text file, the preamble should be <code>nil</code>, and
the contents should be a list of character strings. If it is meant to be
a data file, the preamble should be a non-empty list of character
strings, and the format of the contents is unconstrained. To express a
data file with no preamble, the preamble should be the list containing
the empty string, rather than being empty.
</p>
<p>In the result returned by the function, the preamble lines should not
include leading hash characters, because they are automatically added to
the output to enforce consistency with the data file format. However,
they should include trailing backslashes as continuation characters
where appropriate. The hashes that are automatically added will be
automatically stripped by <code>avram</code> on behalf of whatever application
uses the file.
</p>
<a name="index-character-strings-2"></a>
<a name="index-printing-algorithm-1"></a>
<p>Any file can be written as a list of character strings, even &ldquo;text&rdquo;
files that are full of unprintable characters, and even &ldquo;text&rdquo; files
that happen to conform to the format used for data files.  However, if
the application intends to write a data file in the standard format used
by other virtual code applications, it can do so more quickly and easily
by having the virtual machine do the formatting automatically with the
&lsquo;<samp>--choice-of-output</samp>&rsquo; option than by implementing the algorithm in
<a href="Concrete-Syntax.html#Concrete-Syntax">Concrete Syntax</a>, from scratch in virtual code.
</p>
<hr size="1">
<table cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="Standard-Input-Representation.html#Standard-Input-Representation" title="Previous section in reading order"> &lt; </a>]</td>
<td valign="middle" align="left">[<a href="Line-Maps.html#Line-Maps" title="Next section in reading order"> &gt; </a>]</td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left">[<a href="Virtual-Machine-Specification.html#Virtual-Machine-Specification" title="Beginning of this chapter or previous chapter"> &lt;&lt; </a>]</td>
<td valign="middle" align="left">[<a href="Loading-All-of-Standard-Input-at-Once.html#Loading-All-of-Standard-Input-at-Once" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="Library-Reference.html#Library-Reference" title="Next chapter"> &gt;&gt; </a>]</td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left"> &nbsp; </td>
<td valign="middle" align="left">[<a href="avram.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="avram_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Function-Index.html#Function-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="avram_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<p>
 <font size="-1">
  This document was generated on <i>November 8, 2012</i> using <a href="http://www.nongnu.org/texi2html/"><i>texi2html 1.82</i></a>.
 </font>
 <br>

</p>
</body>
</html>