1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
<html><head><title>XLISP top-level</title>
<link rel="stylesheet" type="text/css" href="reference.css">
</head>
<body>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
<hr>
<h1>top-level</h1>
<hr>
<p><table cellpadding="0" cellspacing="0" style="margin-left:10px"><tbody>
<tr valign="top">
<td><nobr>Type:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>function (subr)</nobr></td>
</tr>
<tr valign="top">
<td><nobr>Source:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>xlbfun.c, xldbug.c</nobr></td>
</tr>
</tbody></table></p>
<h2>Syntax</h2>
<dl>
<dt>(top-level)</dt>
<dd>returns - never returns</dd>
</dl>
<h2>Description</h2>
<p>The 'top-level' function aborts to the top level of XLISP. This may be
from within several levels of the
<nobr><a href="../manual/xlisp-man-004.htm">break loop</a></nobr>.
This is valid for
<a href="break.htm">break</a>s,
<a href="error.htm">error</a>s and
<a href="cerror.htm">cerror</a>s [continuable errors]. If 'top-level'
is evaluated while not in a
<nobr><a href="../manual/xlisp-man-004.htm">break loop</a> ,</nobr>
a message is printed:
<pre class="example">
<font color="#008844">[ back to top level ]</font>
</pre>
<p>This message does not cause XLISP to go into a
<nobr><a href="../manual/xlisp-man-004.htm">break loop</a></nobr>.
The 'top-level' function never actually returns a value.</p>
<h2>Examples</h2>
<pre class="example">
(top-level) <font color="#008844">; [ back to top level ]</font>
(break "out") <font color="#008844">; break: out (1st)</font>
(break "twice") <font color="#008844">; break: twice (2nd)</font>
(top-level) <font color="#008844">; to exit out of the break loop</font>
</pre>
<p><b>Keyboard:</b> In the IBM PC and MS-DOS versions of XLISP, a 'Ctrl+c'
key sequence has the same effect as doing a (top-level). On a Macintosh,
this can be accomplished by a pull-down menu or a 'Command+t'. [I haven't
tested this with Nyquist.]</p>
<p>See the
<a href="../manual/xlisp-man-022.htm#top-level">top-level</a>
function in the <nobr>XLISP 2.0</nobr> manual.</p>
<p><nobr> <a href="#top">Back to Top</nobr></a></p>
<hr>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
</body></html>
|
