102 lines
5.3 KiB
HTML
102 lines
5.3 KiB
HTML
<?xml version="1.0" encoding="utf-8"?>
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml"><head>
|
|
<title>.</title>
|
|
<style type="text/css">
|
|
|
|
* { color: #000; background: #fff; max-width: 700px; }
|
|
tt, pre { background: #dedede; color: #111; font-family: monospace;
|
|
white-space: pre; display: block; width: 100%; }
|
|
.indentedcode { margin-left: 2em; margin-right: 2em; }
|
|
.codeblock {
|
|
background: #dedede; color: #111; font-family: monospace;
|
|
box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
|
|
padding: 7px;
|
|
display: block;
|
|
}
|
|
|
|
.indentedlist { margin-left: 2em; color: #000; }
|
|
|
|
span { white-space: pre; }
|
|
.text { color: #000; white-space: pre; background: #dedede; }
|
|
.colon { color: #000; background: #dedede; }
|
|
.note { color: #000; background: #dedede; }
|
|
.str { color: #000; text-decoration: underline; background: #dedede; }
|
|
.num { color: #000; background: #dedede; font-weight: bold; font-style: italic; }
|
|
.fnum { color: #000; font-weight: bold; background: #dedede; }
|
|
.ptr { color: #000; font-weight: bold; background: #dedede; }
|
|
.fetch { color: #000; font-style: italic; background: #dedede; }
|
|
.store { color: #000; font-style: italic; background: #dedede; }
|
|
.char { color: #000; background: #dedede; }
|
|
.inst { color: #000; background: #dedede; }
|
|
.defer { color: #000; background: #dedede; }
|
|
.imm { color: #000; font-weight: bold; background: #dedede; }
|
|
.prim { color: #000; font-weight: bolder; background: #dedede; }
|
|
|
|
.tt { white-space: pre; font-family: monospace; background: #dedede; }
|
|
|
|
.h1, .h2, .h3, .h4 { white-space: normal; }
|
|
.h1 { font-size: 125%; }
|
|
.h2 { font-size: 120%; }
|
|
.h3 { font-size: 115%; }
|
|
.h4 { font-size: 110%; }
|
|
.hr { display: block; height: 2px; background: #000000; }
|
|
</style>
|
|
</head><body>
|
|
<p><span class="h1">Lexical Scope</span>
|
|
<br/><br/>
|
|
RETRO has a single dictionary, but does provide a means of using
|
|
lexical scope to keep this dictionary clean.
|
|
<br/><br/>
|
|
<span class="h2">Example</span>
|
|
<br/><br/>
|
|
<span class='codeblock'><span class="tt">```</span><br/><span class="tt">{{ </span><br/>
|
|
<span class="tt"> <span class='str'>'A</span> var </span><br/>
|
|
<span class="tt"> <span class='colon'>:++A</span> <span class='ptr'>&A</span> v:inc <span class='imm'>;</span> </span><br/>
|
|
<span class="tt">---reveal--- </span><br/>
|
|
<span class="tt"> <span class='colon'>:B</span> ++A ++A <span class='fetch'>@A</span> n:put nl <span class='imm'>;</span> </span><br/>
|
|
<span class="tt">}} </span><br/>
|
|
<span class="tt">```</span></span><br/><br/>
|
|
In this example, the lexical namespace is created with <span class="tt">{{</span>. A
|
|
variable (<span class="tt">A</span>) and word (<span class="tt">++A</span>) are defined. Then a marker is
|
|
set with <span class="tt">---reveal---</span>. Another word (<span class="tt">B</span>) is defined, and the
|
|
lexical area is closed with <span class="tt">}}</span>.
|
|
<br/><br/>
|
|
The headers between <span class="tt">{{</span> and <span class="tt">---reveal---</span> are then hidden from
|
|
the dictionary, leaving only the headers between <span class="tt">---reveal---</span>
|
|
and <span class="tt">}}</span> exposed.
|
|
<br/><br/>
|
|
If you wish to hide all headers in a <span class="tt">{{</span> ... <span class="tt">}}</span> block, leave
|
|
out the <span class="tt">---reveal---</span>.
|
|
<br/><br/>
|
|
<span class='codeblock'><span class="tt">```</span><br/><span class="tt">{{ </span><br/>
|
|
<span class="tt"> <span class='colon'>:a</span> <span class='num'>#3</span> <span class='imm'>;</span> </span><br/>
|
|
<span class="tt"> <span class='colon'>:b</span> a <span class='prim'>dup</span> <span class='prim'>*</span> <span class='imm'>;</span> </span><br/>
|
|
<span class="tt">}} </span><br/>
|
|
<span class="tt">```</span></span><br/><br/>
|
|
<span class="h2">Notes</span>
|
|
<br/><br/>
|
|
This only affects word visibility within the scoped area. As an
|
|
example:
|
|
<br/><br/>
|
|
<span class='codeblock'><span class="tt">```</span><br/><span class="tt"><span class='colon'>:a</span> <span class='num'>#1</span> <span class='imm'>;</span> </span><br/>
|
|
<span class="tt"> </span><br/>
|
|
<span class="tt">{{ </span><br/>
|
|
<span class="tt"> <span class='colon'>:a</span> <span class='num'>#2</span> <span class='imm'>;</span> </span><br/>
|
|
<span class="tt">---reveal--- </span><br/>
|
|
<span class="tt"> <span class='colon'>:b</span> <span class='str'>'a</span> s:evaluate n:put <span class='imm'>;</span> </span><br/>
|
|
<span class="tt">}} </span><br/>
|
|
<span class="tt">```</span></span><br/><br/>
|
|
In this, after <span class="tt">}}</span> closes the area, the <span class="tt">:a #2 ;</span> is hidden and
|
|
the <span class="tt">s:evaluate</span> will find the <span class="tt">:a #1 ;</span> when <span class="tt">b</span> is run.
|
|
<br/><br/>
|
|
<span class="h2">A Word of Warning</span>
|
|
<br/><br/>
|
|
Use of these words can result in a corrupt dictionary and system
|
|
crashes. Specifically, use of <span class="tt">---reveal---</span> with an empty private
|
|
or public section will result in dictionary corruption.
|
|
<br/><br/>
|
|
If you don't need private words, don't put them in a scope. And if
|
|
you don't need public words, don't include the <span class="tt">---reveal---</span>.
|
|
</p>
|
|
</body></html>
|