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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - linux/arith.mu</title>
<meta name="Generator" content="Vim/8.1">
<meta name="plugin-version" content="vim8.1_v1">
<meta name="syntax" content="none">
<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal-dark">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #000000; background-color: #a8a8a8; }
body { font-size:12pt; font-family: monospace; color: #000000; background-color: #a8a8a8; }
a { color:inherit; }
* { font-size:12pt; font-size: 1em; }
.PreProc { color: #c000c0; }
.Special { color: #ff6060; }
.LineNr { }
.Delimiter { color: #c000c0; }
.CommentedCode { color: #8a8a8a; }
.Constant { color: #008787; }
.muFunction { color: #af5f00; text-decoration: underline; }
.muComment { color: #005faf; }
-->
</style>
<script type='text/javascript'>
<!--
/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
var lineNum;
lineNum = window.location.hash;
lineNum = lineNum.substr(1); /* strip off '#' */
if (lineNum.indexOf('L') == -1) {
lineNum = 'L'+lineNum;
}
var lineElem = document.getElementById(lineNum);
/* Always jump to new location even if the line was hidden inside a fold, or
* we corrected the raw number to a line ID.
*/
if (lineElem) {
lineElem.scrollIntoView(true);
}
return true;
}
if ('onhashchange' in window) {
window.onhashchange = JumpToLine;
}
-->
</script>
</head>
<body onload='JumpToLine();'>
<a href='https://github.com/akkartik/mu/blob/main/linux/arith.mu'>https://github.com/akkartik/mu/blob/main/linux/arith.mu</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="muComment"># Integer arithmetic using conventional precedence.</span>
<span id="L2" class="LineNr"> 2 </span><span class="muComment">#</span>
<span id="L3" class="LineNr"> 3 </span><span class="muComment"># Follows part 2 of Jack Crenshaw's "Let's build a compiler!"</span>
<span id="L4" class="LineNr"> 4 </span><span class="muComment"># <a href="https://compilers.iecc.com/crenshaw">https://compilers.iecc.com/crenshaw</a></span>
<span id="L5" class="LineNr"> 5 </span><span class="muComment">#</span>
<span id="L6" class="LineNr"> 6 </span><span class="muComment"># Limitations:</span>
<span id="L7" class="LineNr"> 7 </span><span class="muComment"># No division yet.</span>
<span id="L8" class="LineNr"> 8 </span><span class="muComment">#</span>
<span id="L9" class="LineNr"> 9 </span><span class="muComment"># To build:</span>
<span id="L10" class="LineNr"> 10 </span><span class="muComment"># $ ./translate arith.mu</span>
<span id="L11" class="LineNr"> 11 </span><span class="muComment">#</span>
<span id="L12" class="LineNr"> 12 </span><span class="muComment"># Example session:</span>
<span id="L13" class="LineNr"> 13 </span><span class="muComment"># $ ./a.elf</span>
<span id="L14" class="LineNr"> 14 </span><span class="muComment"># press ctrl-c or ctrl-d to exit</span>
<span id="L15" class="LineNr"> 15 </span><span class="muComment"># > 1</span>
<span id="L16" class="LineNr"> 16 </span><span class="muComment"># 1</span>
<span id="L17" class="LineNr"> 17 </span><span class="muComment"># > 1+1</span>
<span id="L18" class="LineNr"> 18 </span><span class="muComment"># 2</span>
<span id="L19" class="LineNr"> 19 </span><span class="muComment"># > 1 + 1</span>
<span id="L20" class="LineNr"> 20 </span><span class="muComment"># 2</span>
<span id="L21" class="LineNr"> 21 </span><span class="muComment"># > 1+2 +3</span>
<span id="L22" class="LineNr"> 22 </span><span class="muComment"># 6</span>
<span id="L23" class="LineNr"> 23 </span><span class="muComment"># > 1+2 *3</span>
<span id="L24" class="LineNr"> 24 </span><span class="muComment"># 7</span>
<span id="L25" class="LineNr"> 25 </span><span class="muComment"># > (1+2) *3</span>
<span id="L26" class="LineNr"> 26 </span><span class="muComment"># 9</span>
<span id="L27" class="LineNr"> 27 </span><span class="muComment"># > 1 + 3*4</span>
<span id="L28" class="LineNr"> 28 </span><span class="muComment"># 13</span>
<span id="L29" class="LineNr"> 29 </span><span class="muComment"># > ^D</span>
<span id="L30" class="LineNr"> 30 </span><span class="muComment"># $</span>
<span id="L31" class="LineNr"> 31 </span><span class="muComment">#</span>
<span id="L32" class="LineNr"> 32 </span><span class="muComment"># Error handling is non-existent. This is just a prototype.</span>
<span id="L33" class="LineNr"> 33 </span>
<span id="L34" class="LineNr"> 34 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L34'>main</a></span><span class="PreProc"> -> </span>_/<span class="Constant">ebx</span>: int <span class="Delimiter">{</span>
<span id="L35" class="LineNr"> 35 </span> <a href='305keyboard.subx.html#L6'>enable-keyboard-immediate-mode</a>
<span id="L36" class="LineNr"> 36 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> copy <span class="Constant">0</span> <span class="muComment"># lookahead</span>
<span id="L37" class="LineNr"> 37 </span> <span class="PreProc">var</span> n/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span> <span class="muComment"># result of each expression</span>
<span id="L38" class="LineNr"> 38 </span> <a href='405screen.mu.html#L169'>print-string</a> <span class="Constant">0</span>/screen, <span class="Constant">"press ctrl-c or ctrl-d to exit\n"</span>
<span id="L39" class="LineNr"> 39 </span> <span class="muComment"># read-eval-print loop</span>
<span id="L40" class="LineNr"> 40 </span> <span class="Delimiter">{</span>
<span id="L41" class="LineNr"> 41 </span> <span class="muComment"># print prompt</span>
<span id="L42" class="LineNr"> 42 </span> <a href='405screen.mu.html#L169'>print-string</a> <span class="Constant">0</span>/screen, <span class="Constant">"> "</span>
<span id="L43" class="LineNr"> 43 </span> <span class="muComment"># read and eval</span>
<span id="L44" class="LineNr"> 44 </span> n, look <span class="Special"><-</span> <a href='arith.mu.html#L58'>simplify</a> <span class="muComment"># we explicitly thread 'look' everywhere</span>
<span id="L45" class="LineNr"> 45 </span> <span class="muComment"># if (look == 0) break</span>
<span id="L46" class="LineNr"> 46 </span> compare look, <span class="Constant">0</span>
<span id="L47" class="LineNr"> 47 </span> <span class="PreProc">break-if-=</span>
<span id="L48" class="LineNr"> 48 </span> <span class="muComment"># print</span>
<span id="L49" class="LineNr"> 49 </span> <a href='405screen.mu.html#L484'>print-int32-decimal</a> <span class="Constant">0</span>/screen, n
<span id="L50" class="LineNr"> 50 </span> <a href='405screen.mu.html#L169'>print-string</a> <span class="Constant">0</span>/screen, <span class="Constant">"\n"</span>
<span id="L51" class="LineNr"> 51 </span> <span class="muComment">#</span>
<span id="L52" class="LineNr"> 52 </span> <span class="PreProc">loop</span>
<span id="L53" class="LineNr"> 53 </span> <span class="Delimiter">}</span>
<span id="L54" class="LineNr"> 54 </span> <a href='305keyboard.subx.html#L72'>enable-keyboard-type-mode</a>
<span id="L55" class="LineNr"> 55 </span> <span class="PreProc">return</span> <span class="Constant">0</span>
<span id="L56" class="LineNr"> 56 </span><span class="Delimiter">}</span>
<span id="L57" class="LineNr"> 57 </span>
<span id="L58" class="LineNr"> 58 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L58'>simplify</a></span><span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: int, _/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L59" class="LineNr"> 59 </span> <span class="muComment"># prime the pump</span>
<span id="L60" class="LineNr"> 60 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> <a href='arith.mu.html#L248'>get-char</a>
<span id="L61" class="LineNr"> 61 </span> <span class="muComment"># do it</span>
<span id="L62" class="LineNr"> 62 </span> <span class="PreProc">var</span> result/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L63" class="LineNr"> 63 </span> result, look <span class="Special"><-</span> <a href='arith.mu.html#L67'>expression</a> look
<span id="L64" class="LineNr"> 64 </span> <span class="PreProc">return</span> result, look
<span id="L65" class="LineNr"> 65 </span><span class="Delimiter">}</span>
<span id="L66" class="LineNr"> 66 </span>
<span id="L67" class="LineNr"> 67 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L67'>expression</a></span> _look: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: int, _/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L68" class="LineNr"> 68 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> copy _look
<span id="L69" class="LineNr"> 69 </span> <span class="muComment"># read arg</span>
<span id="L70" class="LineNr"> 70 </span> <span class="PreProc">var</span> result/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L71" class="LineNr"> 71 </span> result, look <span class="Special"><-</span> <a href='arith.mu.html#L112'>term</a> look
<span id="L72" class="LineNr"> 72 </span> $expression:<span class="PreProc">loop</span>: <span class="Delimiter">{</span>
<span id="L73" class="LineNr"> 73 </span> <span class="muComment"># while next non-space char in ['+', '-']</span>
<span id="L74" class="LineNr"> 74 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L75" class="LineNr"> 75 </span> <span class="Delimiter">{</span>
<span id="L76" class="LineNr"> 76 </span> <span class="PreProc">var</span> continue?/<span class="Constant">eax</span>: boolean <span class="Special"><-</span> <a href='arith.mu.html#L191'>add-or-sub?</a> look
<span id="L77" class="LineNr"> 77 </span> compare continue?, <span class="Constant">0</span>/false
<span id="L78" class="LineNr"> 78 </span> <span class="PreProc">break-if-=</span> $expression:<span class="PreProc">loop</span>
<span id="L79" class="LineNr"> 79 </span> <span class="Delimiter">}</span>
<span id="L80" class="LineNr"> 80 </span> <span class="muComment"># read operator</span>
<span id="L81" class="LineNr"> 81 </span> <span class="PreProc">var</span> op/<span class="Constant">ecx</span>: grapheme <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L82" class="LineNr"> 82 </span> op, look <span class="Special"><-</span> operator look
<span id="L83" class="LineNr"> 83 </span> <span class="muComment"># read next arg</span>
<span id="L84" class="LineNr"> 84 </span> <span class="PreProc">var</span> second/<span class="Constant">edx</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L85" class="LineNr"> 85 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L86" class="LineNr"> 86 </span> <span class="Delimiter">{</span>
<span id="L87" class="LineNr"> 87 </span> <span class="PreProc">var</span> tmp/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L88" class="LineNr"> 88 </span> tmp, look <span class="Special"><-</span> <a href='arith.mu.html#L112'>term</a> look
<span id="L89" class="LineNr"> 89 </span> second <span class="Special"><-</span> copy tmp
<span id="L90" class="LineNr"> 90 </span> <span class="Delimiter">}</span>
<span id="L91" class="LineNr"> 91 </span> <span class="muComment"># reduce</span>
<span id="L92" class="LineNr"> 92 </span> $expression:perform-op: <span class="Delimiter">{</span>
<span id="L93" class="LineNr"> 93 </span> <span class="Delimiter">{</span>
<span id="L94" class="LineNr"> 94 </span> compare op, <span class="Constant">0x2b</span>/+
<span id="L95" class="LineNr"> 95 </span> <span class="PreProc">break-if-!=</span>
<span id="L96" class="LineNr"> 96 </span> result <span class="Special"><-</span> add second
<span id="L97" class="LineNr"> 97 </span> <span class="PreProc">break</span> $expression:perform-op
<span id="L98" class="LineNr"> 98 </span> <span class="Delimiter">}</span>
<span id="L99" class="LineNr"> 99 </span> <span class="Delimiter">{</span>
<span id="L100" class="LineNr">100 </span> compare op, <span class="Constant">0x2d</span>/minus
<span id="L101" class="LineNr">101 </span> <span class="PreProc">break-if-!=</span>
<span id="L102" class="LineNr">102 </span> result <span class="Special"><-</span> subtract second
<span id="L103" class="LineNr">103 </span> <span class="PreProc">break</span> $expression:perform-op
<span id="L104" class="LineNr">104 </span> <span class="Delimiter">}</span>
<span id="L105" class="LineNr">105 </span> <span class="Delimiter">}</span>
<span id="L106" class="LineNr">106 </span> <span class="PreProc">loop</span>
<span id="L107" class="LineNr">107 </span> <span class="Delimiter">}</span>
<span id="L108" class="LineNr">108 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L109" class="LineNr">109 </span> <span class="PreProc">return</span> result, look
<span id="L110" class="LineNr">110 </span><span class="Delimiter">}</span>
<span id="L111" class="LineNr">111 </span>
<span id="L112" class="LineNr">112 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L112'>term</a></span> _look: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: int, _/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L113" class="LineNr">113 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> copy _look
<span id="L114" class="LineNr">114 </span> <span class="muComment"># read arg</span>
<span id="L115" class="LineNr">115 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L116" class="LineNr">116 </span> <span class="PreProc">var</span> result/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L117" class="LineNr">117 </span> result, look <span class="Special"><-</span> <a href='arith.mu.html#L157'>factor</a> look
<span id="L118" class="LineNr">118 </span> $term:<span class="PreProc">loop</span>: <span class="Delimiter">{</span>
<span id="L119" class="LineNr">119 </span> <span class="muComment"># while next non-space char in ['*', '/']</span>
<span id="L120" class="LineNr">120 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L121" class="LineNr">121 </span> <span class="Delimiter">{</span>
<span id="L122" class="LineNr">122 </span> <span class="PreProc">var</span> continue?/<span class="Constant">eax</span>: boolean <span class="Special"><-</span> <a href='arith.mu.html#L177'>mul-or-div?</a> look
<span id="L123" class="LineNr">123 </span> compare continue?, <span class="Constant">0</span>/false
<span id="L124" class="LineNr">124 </span> <span class="PreProc">break-if-=</span> $term:<span class="PreProc">loop</span>
<span id="L125" class="LineNr">125 </span> <span class="Delimiter">}</span>
<span id="L126" class="LineNr">126 </span> <span class="muComment"># read operator</span>
<span id="L127" class="LineNr">127 </span> <span class="PreProc">var</span> op/<span class="Constant">ecx</span>: grapheme <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L128" class="LineNr">128 </span> op, look <span class="Special"><-</span> operator look
<span id="L129" class="LineNr">129 </span> <span class="muComment"># read next arg</span>
<span id="L130" class="LineNr">130 </span> <span class="PreProc">var</span> second/<span class="Constant">edx</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L131" class="LineNr">131 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L132" class="LineNr">132 </span> <span class="Delimiter">{</span>
<span id="L133" class="LineNr">133 </span> <span class="PreProc">var</span> tmp/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L134" class="LineNr">134 </span> tmp, look <span class="Special"><-</span> <a href='arith.mu.html#L157'>factor</a> look
<span id="L135" class="LineNr">135 </span> second <span class="Special"><-</span> copy tmp
<span id="L136" class="LineNr">136 </span> <span class="Delimiter">}</span>
<span id="L137" class="LineNr">137 </span> <span class="muComment"># reduce</span>
<span id="L138" class="LineNr">138 </span> $term:perform-op: <span class="Delimiter">{</span>
<span id="L139" class="LineNr">139 </span> <span class="Delimiter">{</span>
<span id="L140" class="LineNr">140 </span> compare op, <span class="Constant">0x2a</span>/*
<span id="L141" class="LineNr">141 </span> <span class="PreProc">break-if-!=</span>
<span id="L142" class="LineNr">142 </span> result <span class="Special"><-</span> multiply second
<span id="L143" class="LineNr">143 </span> <span class="PreProc">break</span> $term:perform-op
<span id="L144" class="LineNr">144 </span> <span class="Delimiter">}</span>
<span id="L145" class="LineNr">145 </span><span class="CommentedCode">#? {</span>
<span id="L146" class="LineNr">146 </span><span class="CommentedCode">#? compare op, 0x2f/slash</span>
<span id="L147" class="LineNr">147 </span><span class="CommentedCode">#? break-if-!=</span>
<span id="L148" class="LineNr">148 </span><span class="CommentedCode">#? result <- divide second # not in Mu yet</span>
<span id="L149" class="LineNr">149 </span><span class="CommentedCode">#? break $term:perform-op</span>
<span id="L150" class="LineNr">150 </span><span class="CommentedCode">#? }</span>
<span id="L151" class="LineNr">151 </span> <span class="Delimiter">}</span>
<span id="L152" class="LineNr">152 </span> <span class="PreProc">loop</span>
<span id="L153" class="LineNr">153 </span> <span class="Delimiter">}</span>
<span id="L154" class="LineNr">154 </span> <span class="PreProc">return</span> result, look
<span id="L155" class="LineNr">155 </span><span class="Delimiter">}</span>
<span id="L156" class="LineNr">156 </span>
<span id="L157" class="LineNr">157 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L157'>factor</a></span> _look: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: int, _/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L158" class="LineNr">158 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> copy _look <span class="muComment"># should be a no-op</span>
<span id="L159" class="LineNr">159 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L160" class="LineNr">160 </span> <span class="muComment"># if next char is not '(', parse a number</span>
<span id="L161" class="LineNr">161 </span> compare look, <span class="Constant">0x28</span>/open-paren
<span id="L162" class="LineNr">162 </span> <span class="Delimiter">{</span>
<span id="L163" class="LineNr">163 </span> <span class="PreProc">break-if-=</span>
<span id="L164" class="LineNr">164 </span> <span class="PreProc">var</span> result/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L165" class="LineNr">165 </span> result, look <span class="Special"><-</span> <a href='arith.mu.html#L211'>num</a> look
<span id="L166" class="LineNr">166 </span> <span class="PreProc">return</span> result, look
<span id="L167" class="LineNr">167 </span> <span class="Delimiter">}</span>
<span id="L168" class="LineNr">168 </span> <span class="muComment"># otherwise recurse</span>
<span id="L169" class="LineNr">169 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L248'>get-char</a> <span class="muComment"># '('</span>
<span id="L170" class="LineNr">170 </span> <span class="PreProc">var</span> result/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L171" class="LineNr">171 </span> result, look <span class="Special"><-</span> <a href='arith.mu.html#L67'>expression</a> look
<span id="L172" class="LineNr">172 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L237'>skip-spaces</a> look
<span id="L173" class="LineNr">173 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L248'>get-char</a> <span class="muComment"># ')'</span>
<span id="L174" class="LineNr">174 </span> <span class="PreProc">return</span> result, look
<span id="L175" class="LineNr">175 </span><span class="Delimiter">}</span>
<span id="L176" class="LineNr">176 </span>
<span id="L177" class="LineNr">177 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L177'>mul-or-div?</a></span> c: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: boolean <span class="Delimiter">{</span>
<span id="L178" class="LineNr">178 </span> compare c, <span class="Constant">0x2a</span>/*
<span id="L179" class="LineNr">179 </span> <span class="Delimiter">{</span>
<span id="L180" class="LineNr">180 </span> <span class="PreProc">break-if-!=</span>
<span id="L181" class="LineNr">181 </span> <span class="PreProc">return</span> <span class="Constant">1</span>/true
<span id="L182" class="LineNr">182 </span> <span class="Delimiter">}</span>
<span id="L183" class="LineNr">183 </span> compare c, <span class="Constant">0x2f</span>/slash
<span id="L184" class="LineNr">184 </span> <span class="Delimiter">{</span>
<span id="L185" class="LineNr">185 </span> <span class="PreProc">break-if-!=</span>
<span id="L186" class="LineNr">186 </span> <span class="PreProc">return</span> <span class="Constant">1</span>/true
<span id="L187" class="LineNr">187 </span> <span class="Delimiter">}</span>
<span id="L188" class="LineNr">188 </span> <span class="PreProc">return</span> <span class="Constant">0</span>/false
<span id="L189" class="LineNr">189 </span><span class="Delimiter">}</span>
<span id="L190" class="LineNr">190 </span>
<span id="L191" class="LineNr">191 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L191'>add-or-sub?</a></span> c: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: boolean <span class="Delimiter">{</span>
<span id="L192" class="LineNr">192 </span> compare c, <span class="Constant">0x2b</span>/+
<span id="L193" class="LineNr">193 </span> <span class="Delimiter">{</span>
<span id="L194" class="LineNr">194 </span> <span class="PreProc">break-if-!=</span>
<span id="L195" class="LineNr">195 </span> <span class="PreProc">return</span> <span class="Constant">1</span>/true
<span id="L196" class="LineNr">196 </span> <span class="Delimiter">}</span>
<span id="L197" class="LineNr">197 </span> compare c, <span class="Constant">0x2d</span>/minus
<span id="L198" class="LineNr">198 </span> <span class="Delimiter">{</span>
<span id="L199" class="LineNr">199 </span> <span class="PreProc">break-if-!=</span>
<span id="L200" class="LineNr">200 </span> <span class="PreProc">return</span> <span class="Constant">1</span>/true
<span id="L201" class="LineNr">201 </span> <span class="Delimiter">}</span>
<span id="L202" class="LineNr">202 </span> <span class="PreProc">return</span> <span class="Constant">0</span>/false
<span id="L203" class="LineNr">203 </span><span class="Delimiter">}</span>
<span id="L204" class="LineNr">204 </span>
<span id="L205" class="LineNr">205 </span><span class="PreProc">fn</span> <span class="muFunction">operator</span> _look: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">ecx</span>: grapheme, _/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L206" class="LineNr">206 </span> <span class="PreProc">var</span> op/<span class="Constant">ecx</span>: grapheme <span class="Special"><-</span> copy _look
<span id="L207" class="LineNr">207 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> <a href='arith.mu.html#L248'>get-char</a>
<span id="L208" class="LineNr">208 </span> <span class="PreProc">return</span> op, look
<span id="L209" class="LineNr">209 </span><span class="Delimiter">}</span>
<span id="L210" class="LineNr">210 </span>
<span id="L211" class="LineNr">211 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L211'>num</a></span> _look: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">eax</span>: int, _/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L212" class="LineNr">212 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> copy _look
<span id="L213" class="LineNr">213 </span> <span class="PreProc">var</span> result/<span class="Constant">edi</span>: int <span class="Special"><-</span> copy <span class="Constant">0</span>
<span id="L214" class="LineNr">214 </span> <span class="Delimiter">{</span>
<span id="L215" class="LineNr">215 </span> <span class="PreProc">var</span> first-digit/<span class="Constant">eax</span>: int <span class="Special"><-</span> <a href='126write-int-decimal.subx.html#L405'>to-decimal-digit</a> look
<span id="L216" class="LineNr">216 </span> result <span class="Special"><-</span> copy first-digit
<span id="L217" class="LineNr">217 </span> <span class="Delimiter">}</span>
<span id="L218" class="LineNr">218 </span> <span class="Delimiter">{</span>
<span id="L219" class="LineNr">219 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L248'>get-char</a>
<span id="L220" class="LineNr">220 </span> <span class="muComment"># done?</span>
<span id="L221" class="LineNr">221 </span> <span class="PreProc">var</span> digit?/<span class="Constant">eax</span>: boolean <span class="Special"><-</span> <a href='126write-int-decimal.subx.html#L306'>decimal-digit?</a> look
<span id="L222" class="LineNr">222 </span> compare digit?, <span class="Constant">0</span>/false
<span id="L223" class="LineNr">223 </span> <span class="PreProc">break-if-=</span>
<span id="L224" class="LineNr">224 </span> <span class="muComment"># result *= 10</span>
<span id="L225" class="LineNr">225 </span> <span class="Delimiter">{</span>
<span id="L226" class="LineNr">226 </span> <span class="PreProc">var</span> ten/<span class="Constant">eax</span>: int <span class="Special"><-</span> copy <span class="Constant">0xa</span>
<span id="L227" class="LineNr">227 </span> result <span class="Special"><-</span> multiply ten
<span id="L228" class="LineNr">228 </span> <span class="Delimiter">}</span>
<span id="L229" class="LineNr">229 </span> <span class="muComment"># result += digit(look)</span>
<span id="L230" class="LineNr">230 </span> <span class="PreProc">var</span> digit/<span class="Constant">eax</span>: int <span class="Special"><-</span> <a href='126write-int-decimal.subx.html#L405'>to-decimal-digit</a> look
<span id="L231" class="LineNr">231 </span> result <span class="Special"><-</span> add digit
<span id="L232" class="LineNr">232 </span> <span class="PreProc">loop</span>
<span id="L233" class="LineNr">233 </span> <span class="Delimiter">}</span>
<span id="L234" class="LineNr">234 </span> <span class="PreProc">return</span> result, look
<span id="L235" class="LineNr">235 </span><span class="Delimiter">}</span>
<span id="L236" class="LineNr">236 </span>
<span id="L237" class="LineNr">237 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L237'>skip-spaces</a></span> _look: grapheme<span class="PreProc"> -> </span>_/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L238" class="LineNr">238 </span> <span class="PreProc">var</span> look/<span class="Constant">esi</span>: grapheme <span class="Special"><-</span> copy _look <span class="muComment"># should be a no-op</span>
<span id="L239" class="LineNr">239 </span> <span class="Delimiter">{</span>
<span id="L240" class="LineNr">240 </span> compare look, <span class="Constant">0x20</span>
<span id="L241" class="LineNr">241 </span> <span class="PreProc">break-if-!=</span>
<span id="L242" class="LineNr">242 </span> look <span class="Special"><-</span> <a href='arith.mu.html#L248'>get-char</a>
<span id="L243" class="LineNr">243 </span> <span class="PreProc">loop</span>
<span id="L244" class="LineNr">244 </span> <span class="Delimiter">}</span>
<span id="L245" class="LineNr">245 </span> <span class="PreProc">return</span> look
<span id="L246" class="LineNr">246 </span><span class="Delimiter">}</span>
<span id="L247" class="LineNr">247 </span>
<span id="L248" class="LineNr">248 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='arith.mu.html#L248'>get-char</a></span><span class="PreProc"> -> </span>_/<span class="Constant">esi</span>: grapheme <span class="Delimiter">{</span>
<span id="L249" class="LineNr">249 </span> <span class="PreProc">var</span> look/<span class="Constant">eax</span>: grapheme <span class="Special"><-</span> <a href='305keyboard.subx.html#L132'>read-key-from-real-keyboard</a>
<span id="L250" class="LineNr">250 </span> <a href='304screen.subx.html#L161'>print-grapheme-to-real-screen</a> look
<span id="L251" class="LineNr">251 </span> compare look, <span class="Constant">4</span>
<span id="L252" class="LineNr">252 </span> <span class="Delimiter">{</span>
<span id="L253" class="LineNr">253 </span> <span class="PreProc">break-if-!=</span>
<span id="L254" class="LineNr">254 </span> <a href='405screen.mu.html#L169'>print-string</a> <span class="Constant">0</span>/screen, <span class="Constant">"^D\n"</span>
<span id="L255" class="LineNr">255 </span> <a href='000init.subx.html#L18'>syscall_exit</a>
<span id="L256" class="LineNr">256 </span> <span class="Delimiter">}</span>
<span id="L257" class="LineNr">257 </span> <span class="PreProc">return</span> look
<span id="L258" class="LineNr">258 </span><span class="Delimiter">}</span>
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->
|