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
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
|
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="generator" content="Docutils 0.17.1: http://docutils.sourceforge.net/" />
<title>ctags-lang-python</title>
<style type="text/css">
/*
:Author: David Goodger (goodger@python.org)
:Id: $Id: html4css1.css 7952 2016-07-26 18:15:59Z milde $
:Copyright: This stylesheet has been placed in the public domain.
Default cascading style sheet for the HTML output of Docutils.
See http://docutils.sf.net/docs/howto/html-stylesheets.html for how to
customize this style sheet.
*/
/* used to remove borders from tables and images */
.borderless, table.borderless td, table.borderless th {
border: 0 }
table.borderless td, table.borderless th {
/* Override padding for "table.docutils td" with "! important".
The right padding separates the table cells. */
padding: 0 0.5em 0 0 ! important }
.first {
/* Override more specific margin styles with "! important". */
margin-top: 0 ! important }
.last, .with-subtitle {
margin-bottom: 0 ! important }
.hidden {
display: none }
.subscript {
vertical-align: sub;
font-size: smaller }
.superscript {
vertical-align: super;
font-size: smaller }
a.toc-backref {
text-decoration: none ;
color: black }
blockquote.epigraph {
margin: 2em 5em ; }
dl.docutils dd {
margin-bottom: 0.5em }
object[type="image/svg+xml"], object[type="application/x-shockwave-flash"] {
overflow: hidden;
}
/* Uncomment (and remove this text!) to get bold-faced definition list terms
dl.docutils dt {
font-weight: bold }
*/
div.abstract {
margin: 2em 5em }
div.abstract p.topic-title {
font-weight: bold ;
text-align: center }
div.admonition, div.attention, div.caution, div.danger, div.error,
div.hint, div.important, div.note, div.tip, div.warning {
margin: 2em ;
border: medium outset ;
padding: 1em }
div.admonition p.admonition-title, div.hint p.admonition-title,
div.important p.admonition-title, div.note p.admonition-title,
div.tip p.admonition-title {
font-weight: bold ;
font-family: sans-serif }
div.attention p.admonition-title, div.caution p.admonition-title,
div.danger p.admonition-title, div.error p.admonition-title,
div.warning p.admonition-title, .code .error {
color: red ;
font-weight: bold ;
font-family: sans-serif }
/* Uncomment (and remove this text!) to get reduced vertical space in
compound paragraphs.
div.compound .compound-first, div.compound .compound-middle {
margin-bottom: 0.5em }
div.compound .compound-last, div.compound .compound-middle {
margin-top: 0.5em }
*/
div.dedication {
margin: 2em 5em ;
text-align: center ;
font-style: italic }
div.dedication p.topic-title {
font-weight: bold ;
font-style: normal }
div.figure {
margin-left: 2em ;
margin-right: 2em }
div.footer, div.header {
clear: both;
font-size: smaller }
div.line-block {
display: block ;
margin-top: 1em ;
margin-bottom: 1em }
div.line-block div.line-block {
margin-top: 0 ;
margin-bottom: 0 ;
margin-left: 1.5em }
div.sidebar {
margin: 0 0 0.5em 1em ;
border: medium outset ;
padding: 1em ;
background-color: #ffffee ;
width: 40% ;
float: right ;
clear: right }
div.sidebar p.rubric {
font-family: sans-serif ;
font-size: medium }
div.system-messages {
margin: 5em }
div.system-messages h1 {
color: red }
div.system-message {
border: medium outset ;
padding: 1em }
div.system-message p.system-message-title {
color: red ;
font-weight: bold }
div.topic {
margin: 2em }
h1.section-subtitle, h2.section-subtitle, h3.section-subtitle,
h4.section-subtitle, h5.section-subtitle, h6.section-subtitle {
margin-top: 0.4em }
h1.title {
text-align: center }
h2.subtitle {
text-align: center }
hr.docutils {
width: 75% }
img.align-left, .figure.align-left, object.align-left, table.align-left {
clear: left ;
float: left ;
margin-right: 1em }
img.align-right, .figure.align-right, object.align-right, table.align-right {
clear: right ;
float: right ;
margin-left: 1em }
img.align-center, .figure.align-center, object.align-center {
display: block;
margin-left: auto;
margin-right: auto;
}
table.align-center {
margin-left: auto;
margin-right: auto;
}
.align-left {
text-align: left }
.align-center {
clear: both ;
text-align: center }
.align-right {
text-align: right }
/* reset inner alignment in figures */
div.align-right {
text-align: inherit }
/* div.align-center * { */
/* text-align: left } */
.align-top {
vertical-align: top }
.align-middle {
vertical-align: middle }
.align-bottom {
vertical-align: bottom }
ol.simple, ul.simple {
margin-bottom: 1em }
ol.arabic {
list-style: decimal }
ol.loweralpha {
list-style: lower-alpha }
ol.upperalpha {
list-style: upper-alpha }
ol.lowerroman {
list-style: lower-roman }
ol.upperroman {
list-style: upper-roman }
p.attribution {
text-align: right ;
margin-left: 50% }
p.caption {
font-style: italic }
p.credits {
font-style: italic ;
font-size: smaller }
p.label {
white-space: nowrap }
p.rubric {
font-weight: bold ;
font-size: larger ;
color: maroon ;
text-align: center }
p.sidebar-title {
font-family: sans-serif ;
font-weight: bold ;
font-size: larger }
p.sidebar-subtitle {
font-family: sans-serif ;
font-weight: bold }
p.topic-title {
font-weight: bold }
pre.address {
margin-bottom: 0 ;
margin-top: 0 ;
font: inherit }
pre.literal-block, pre.doctest-block, pre.math, pre.code {
margin-left: 2em ;
margin-right: 2em }
pre.code .ln { color: grey; } /* line numbers */
pre.code, code { background-color: #eeeeee }
pre.code .comment, code .comment { color: #5C6576 }
pre.code .keyword, code .keyword { color: #3B0D06; font-weight: bold }
pre.code .literal.string, code .literal.string { color: #0C5404 }
pre.code .name.builtin, code .name.builtin { color: #352B84 }
pre.code .deleted, code .deleted { background-color: #DEB0A1}
pre.code .inserted, code .inserted { background-color: #A3D289}
span.classifier {
font-family: sans-serif ;
font-style: oblique }
span.classifier-delimiter {
font-family: sans-serif ;
font-weight: bold }
span.interpreted {
font-family: sans-serif }
span.option {
white-space: nowrap }
span.pre {
white-space: pre }
span.problematic {
color: red }
span.section-subtitle {
/* font-size relative to parent (h1..h6 element) */
font-size: 80% }
table.citation {
border-left: solid 1px gray;
margin-left: 1px }
table.docinfo {
margin: 2em 4em }
table.docutils {
margin-top: 0.5em ;
margin-bottom: 0.5em }
table.footnote {
border-left: solid 1px black;
margin-left: 1px }
table.docutils td, table.docutils th,
table.docinfo td, table.docinfo th {
padding-left: 0.5em ;
padding-right: 0.5em ;
vertical-align: top }
table.docutils th.field-name, table.docinfo th.docinfo-name {
font-weight: bold ;
text-align: left ;
white-space: nowrap ;
padding-left: 0 }
/* "booktabs" style (no vertical lines) */
table.docutils.booktabs {
border: 0px;
border-top: 2px solid;
border-bottom: 2px solid;
border-collapse: collapse;
}
table.docutils.booktabs * {
border: 0px;
}
table.docutils.booktabs th {
border-bottom: thin solid;
text-align: left;
}
h1 tt.docutils, h2 tt.docutils, h3 tt.docutils,
h4 tt.docutils, h5 tt.docutils, h6 tt.docutils {
font-size: 100% }
ul.auto-toc {
list-style-type: none }
</style>
</head>
<body>
<div class="document" id="ctags-lang-python">
<span id="ctags-lang-python-7"></span>
<h1 class="title">ctags-lang-python</h1>
<h2 class="subtitle" id="random-notes-about-tagging-python-source-code-with-universal-ctags">Random notes about tagging python source code with Universal Ctags</h2>
<table class="docinfo" frame="void" rules="none">
<col class="docinfo-name" />
<col class="docinfo-content" />
<tbody valign="top">
<tr><th class="docinfo-name">Version:</th>
<td>5.9.0</td></tr>
<tr class="manual-group field"><th class="docinfo-name">Manual group:</th><td class="field-body">Universal Ctags</td>
</tr>
<tr class="manual-section field"><th class="docinfo-name">Manual section:</th><td class="field-body">7</td>
</tr>
</tbody>
</table>
<div class="section" id="synopsis">
<h1>SYNOPSIS</h1>
<div class="line-block">
<div class="line"><strong>ctags</strong> ... --languages=+Python ...</div>
<div class="line"><strong>ctags</strong> ... --language-force=Python ...</div>
<div class="line"><strong>ctags</strong> ... --map-Python=+.py ...</div>
</div>
</div>
<div class="section" id="description">
<h1>DESCRIPTION</h1>
<p>This man page gathers random notes about tagging python source code.</p>
</div>
<div class="section" id="tagging-import-statements">
<h1>TAGGING <tt class="docutils literal">import</tt> STATEMENTS</h1>
<div class="section" id="summary">
<h2>Summary</h2>
<p><cite>import X</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="7%" />
<col width="18%" />
<col width="33%" />
<col width="42%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td>X</td>
<td>module</td>
<td>imported</td>
<td>N/A</td>
</tr>
</tbody>
</table>
</blockquote>
<p><cite>import X as Y</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="7%" />
<col width="18%" />
<col width="33%" />
<col width="42%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td>X</td>
<td>module</td>
<td>indirectlyImported</td>
<td>N/A</td>
</tr>
<tr><td>Y</td>
<td>namespace</td>
<td>definition</td>
<td>nameref:module:X</td>
</tr>
</tbody>
</table>
</blockquote>
<p><cite>from X import *</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="7%" />
<col width="18%" />
<col width="33%" />
<col width="42%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><cite>X</cite></td>
<td>module</td>
<td>namespace</td>
<td>N/A</td>
</tr>
</tbody>
</table>
</blockquote>
<p><cite>from X import Y</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="7%" />
<col width="18%" />
<col width="33%" />
<col width="42%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><cite>X</cite></td>
<td>module</td>
<td>namespace</td>
<td>N/A</td>
</tr>
<tr><td><cite>Y</cite></td>
<td>unknown</td>
<td>imported</td>
<td>scope:module:<cite>X</cite></td>
</tr>
</tbody>
</table>
</blockquote>
<p><cite>from X import Y as Z</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="7%" />
<col width="18%" />
<col width="33%" />
<col width="42%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><cite>X</cite></td>
<td>module</td>
<td>namespace</td>
<td>N/A</td>
</tr>
<tr><td><cite>Y</cite></td>
<td>unknown</td>
<td>indirectlyImported</td>
<td>scope:module:<cite>X</cite></td>
</tr>
<tr><td><cite>Z</cite></td>
<td>unknown</td>
<td>definition</td>
<td>nameref:unknown:<cite>X</cite></td>
</tr>
</tbody>
</table>
</blockquote>
<!-- ===================== ==== ========== ================== ===================
input code name kind role other noticeable fields
===================== ==== ========== ================== ===================
import X X module imported
import X as Y X module indirectlyImported
import X as Y Y namespace definition nameref:module:X
from X import * X module namespace
from X import Y X module namespace
from X import Y Y unknown imported scope:module:X
from X import Y as Z X module namespace
from X import Y as Z Y unknown indirectlyImported scope:module:X
from X import Y as Z Z unknown definition nameref:unknown:X
===================== ==== ========== ================== =================== -->
<!-- a table having merged cells cannot be converted to man page -->
<!-- +- - - - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -+
|input code |output tags |
| +- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
| |name| kind |role |other noticeable fields |
+====================+====+==========+==================+===================+
|import X |X | module |imported | |
+- - - - - - - - - - - - - - - - - - - -+- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
|import X as Y |X | module |indirectlyImported| |
| +- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
| |Y | namespace|definition |nameref:module:X |
+- - - - - - - - - - - - - - - - - - - -+- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
|from X import * |X | module |namespace | |
+- - - - - - - - - - - - - - - - - - - -+- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
|from X import Y |X | module |namespace | |
| +- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
| |Y | unknown |imported |scope:module:X |
+- - - - - - - - - - - - - - - - - - - -+- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
|from X import Y as Z|X | module |namespace | |
| +- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
| |Y | unknown |indirectlyImported|scope:module:X |
| +- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+
| |Z | unknown |definition |nameref:unknown:Y |
+- - - - - - - - - - - - - - - - - - - -+- - - -+- - - - - - - - - -+- - - - - - - - - - - - - - - - - -+- - - - - - - - - - - - - - - - - - -+ -->
</div>
<div class="section" id="examples">
<h2>Examples</h2>
<p>"input.py"</p>
<pre class="code Python literal-block">
<span class="keyword namespace">import</span> <span class="name namespace">X0</span>
</pre>
<p>"output.tags"
with "--options=NONE -o - --extras=+r --fields=+rzK input.py"</p>
<div class="system-message">
<p class="system-message-title">System Message: WARNING/2 (<tt class="docutils">ctags-lang-python.7.rst</tt>, line 125)</p>
<p>Cannot analyze code. No Pygments lexer found for "tags".</p>
<pre class="literal-block">
.. code-block:: tags
X0 input.py /^import X0$/;" kind:module roles:imported
</pre>
</div>
<p>A tag for an imported module has <tt class="docutils literal">module</tt> kind with <tt class="docutils literal">imported</tt> role. The
module is not defined here; it is defined in another file. So the tag for the
imported module is a reference tag; specify <tt class="docutils literal"><span class="pre">--extras=+r</span></tt> (or
<tt class="docutils literal"><span class="pre">--extras=+{reference}</span></tt>) option for tagging it. "roles:" field enabled with
<tt class="docutils literal"><span class="pre">--fields=+r</span></tt> is for recording the module is "imported" to the tag file.</p>
<p>"input.py"</p>
<pre class="code Python literal-block">
<span class="keyword namespace">import</span> <span class="name namespace">X1</span> <span class="keyword">as</span> <span class="name namespace">Y1</span>
</pre>
<p>"output.tags"
with "--options=NONE -o - --extras=+r --fields=+rzK --fields-Python=+{nameref} input.py"</p>
<div class="system-message">
<p class="system-message-title">System Message: WARNING/2 (<tt class="docutils">ctags-lang-python.7.rst</tt>, line 144)</p>
<p>Cannot analyze code. No Pygments lexer found for "tags".</p>
<pre class="literal-block">
.. code-block:: tags
X1 input.py /^import X1 as Y1$/;" kind:module roles:indirectlyImported
Y1 input.py /^import X1 as Y1$/;" kind:namespace roles:def nameref:module:X1
</pre>
</div>
<p>"Y1" introduces a new name and is defined here. So "Y1" is tagged as a
definition tag. "X1" is imported in a way that its name cannot be used
in this source file. For letting client tools know that the name cannot be used,
<tt class="docutils literal">indirectlyImported</tt> role is assigned for "X1". "Y1" is the name for
accessing objects defined in the module imported via "X1". For recording this
relationship, <tt class="docutils literal">nameref:</tt> field is attached to the tag of "Y1". Instead of
<tt class="docutils literal">module</tt> kind, <tt class="docutils literal">namespace</tt> kind is assigned to "Y1" because "Y1" itself
isn't a module.</p>
<p>"input.py"</p>
<pre class="code Python literal-block">
<span class="keyword namespace">from</span> <span class="name namespace">X2</span> <span class="keyword namespace">import</span> <span class="operator">*</span>
</pre>
<p>"output.tags"
with "--options=NONE -o - --extras=+r --fields=+rzK input.py"</p>
<div class="system-message">
<p class="system-message-title">System Message: WARNING/2 (<tt class="docutils">ctags-lang-python.7.rst</tt>, line 167)</p>
<p>Cannot analyze code. No Pygments lexer found for "tags".</p>
<pre class="literal-block">
.. code-block:: tags
X2 input.py /^from X2 import *$/;" kind:module roles:namespace
</pre>
</div>
<p>The module is not defined here; it is defined in another file. So the tag for
the imported module is a reference tag. Unlike "X0" in "import X0", "X2" may not
be used because the names defined in "X2" can be used in this source file. To represent
the difference <tt class="docutils literal">namespace</tt> role is attached to "X2" instead of <tt class="docutils literal">imported</tt>.</p>
<p>"input.py"</p>
<pre class="code Python literal-block">
<span class="keyword namespace">from</span> <span class="name namespace">X3</span> <span class="keyword namespace">import</span> <span class="name">Y3</span>
</pre>
<p>"output.tags"
with "--options=NONE -o - --extras=+r --fields=+rzKZ input.py"</p>
<div class="system-message">
<p class="system-message-title">System Message: WARNING/2 (<tt class="docutils">ctags-lang-python.7.rst</tt>, line 185)</p>
<p>Cannot analyze code. No Pygments lexer found for "tags".</p>
<pre class="literal-block">
.. code-block:: tags
X3 input.py /^from X3 import Y3$/;" kind:module roles:namespace
Y3 input.py /^from X3 import Y3$/;" kind:unknown scope:module:X3 roles:imported
</pre>
</div>
<p>"Y3" is a name for a language object defined in "X3" module. "scope:module:X3"
attached to "Y3" represents this relation between "Y3" and "X3". ctags
assigns <tt class="docutils literal">unknown</tt> kind to "Y3" because ctags cannot know whether "Y3" is a
class, a variable, or a function from the input file.</p>
<p>"input.py"</p>
<pre class="code Python literal-block">
<span class="keyword namespace">from</span> <span class="name namespace">X4</span> <span class="keyword namespace">import</span> <span class="name">Y4</span> <span class="keyword">as</span> <span class="name">Z4</span>
</pre>
<p>"output.tags"
with "--options=NONE -o - --extras=+r --fields=+rzKZ input.py"</p>
<div class="system-message">
<p class="system-message-title">System Message: WARNING/2 (<tt class="docutils">ctags-lang-python.7.rst</tt>, line 204)</p>
<p>Cannot analyze code. No Pygments lexer found for "tags".</p>
<pre class="literal-block">
.. code-block:: tags
X4 input.py /^from X4 import Y4 as Z4$/;" kind:module roles:namespace
Y4 input.py /^from X4 import Y4 as Z4$/;" kind:unknown scope:module:X4 roles:indirectlyImported
Z4 input.py /^from X4 import Y4 as Z4$/;" kind:unknown roles:def nameref:unknown:Y4
</pre>
</div>
<p>"Y4" is similar to "Y3" of "from X3 import Y3" but the name cannot be used here.
<tt class="docutils literal">indirectlyImported</tt> role assigned to "Y4" representing this. "Z4" is the name for
accessing the language object named in "Y4" in "X4" module. "nameref:unknown:Y4"
attached to "Z4" and "scope:module:X4" attached to "Y4" represent the relations.</p>
</div>
</div>
<div class="section" id="lambda-expression-and-type-hint">
<h1>LAMBDA EXPRESSION AND TYPE HINT</h1>
<div class="section" id="id1">
<h2>Summary</h2>
<p><cite>id = lambda var0: var0</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="18%" />
<col width="16%" />
<col width="29%" />
<col width="37%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><cite>id</cite></td>
<td>function</td>
<td>definition</td>
<td>signature:(<cite>var0</cite>)</td>
</tr>
</tbody>
</table>
</blockquote>
<p><cite>id_t: Callable[[int], int] = lambda var1: var1</cite></p>
<blockquote>
<table border="1" class="docutils">
<colgroup>
<col width="10%" />
<col width="10%" />
<col width="17%" />
<col width="63%" />
</colgroup>
<thead valign="bottom">
<tr><th class="head">name</th>
<th class="head">kind</th>
<th class="head">role</th>
<th class="head">other noticeable fields</th>
</tr>
</thead>
<tbody valign="top">
<tr><td><cite>id_t</cite></td>
<td>variable</td>
<td>definition</td>
<td>typeref:typename:<cite>Callable[[int], int]</cite> nameref:function:anonFuncN</td>
</tr>
<tr><td>anonFuncN</td>
<td>function</td>
<td>definition</td>
<td>signature:(<cite>var1</cite>)</td>
</tr>
</tbody>
</table>
</blockquote>
</div>
<div class="section" id="id2">
<h2>Examples</h2>
<p>"input.py"</p>
<pre class="code Python literal-block">
<span class="keyword namespace">from</span> <span class="name namespace">typing</span> <span class="keyword namespace">import</span> <span class="name">Callable</span>
<span class="name builtin">id</span> <span class="operator">=</span> <span class="keyword">lambda</span> <span class="name">var0</span><span class="punctuation">:</span> <span class="name">var0</span>
<span class="name">id_t</span><span class="punctuation">:</span> <span class="name">Callable</span><span class="punctuation">[[</span><span class="name builtin">int</span><span class="punctuation">],</span> <span class="name builtin">int</span><span class="punctuation">]</span> <span class="operator">=</span> <span class="keyword">lambda</span> <span class="name">var1</span><span class="punctuation">:</span> <span class="name">var1</span>
</pre>
<p>"output.tags"
with "--options=NONE -o - --sort=no --fields=+KS --fields-Python=+{nameref} --extras=+{anonymous} input.py"</p>
<div class="system-message">
<p class="system-message-title">System Message: WARNING/2 (<tt class="docutils">ctags-lang-python.7.rst</tt>, line 251)</p>
<p>Cannot analyze code. No Pygments lexer found for "tags".</p>
<pre class="literal-block">
.. code-block:: tags
id input.py /^id = lambda var0: var0$/;" function signature:(var0)
id_t input.py /^id_t: Callable[[int], int] = lambda var1: var1$/;"\
variable typeref:typename:Callable[[int], int] nameref:function:anonFunc84011d2c0101
anonFunc84011d2c0101 input.py /^id_t: Callable[[int], int] = lambda var1: var1$/;"\
function signature:(var1)
</pre>
</div>
<p>If a variable ("id") with no type hint is initialized with a lambda expression,
ctags assigns <tt class="docutils literal">function</tt> kind for the tag of "id".</p>
<p>If a variable ("id_t") with a type hint is initialized with a lambda expression,
ctags assigns <tt class="docutils literal">variable</tt> kind for the tag of "id_t" with <tt class="docutils literal">typeref:</tt> and
<tt class="docutils literal">nameref:</tt> fields. ctags fills <tt class="docutils literal">typeref:</tt> field with the value of the type
hint. The way of filling <tt class="docutils literal">nameref:</tt> is a bit complicated.</p>
<p>For the lambda expression used in initializing the type-hint'ed variable, ctags
creates <tt class="docutils literal">anonymous</tt> extra tag ("anonFunc84011d2c0101"). ctags fills the
<tt class="docutils literal">nameref:</tt> field of "id_t" with the name of <tt class="docutils literal">anonymous</tt> extra tag:
"nameref:function:anonFunc84011d2c0101".</p>
<p>You may think why ctags does so complicated, and why ctags doesn't emit
following tags output for the input:</p>
<pre class="literal-block">
id input.py /^id = \\$/;" function signature:(var0)
id_t input.py /^id_t: \\$/;" function typeref:typename:Callable[[int], int] signature:(var1)
</pre>
<p>There is a reason. The other languages of ctags obey the following rule: ctags fills
<tt class="docutils literal">typeref:</tt> field for a tag of a callable object (like function) with the type
of its return value. If we consider "id_t" is a function, its <tt class="docutils literal">typeref:</tt> field
should have "typename:int". However, for filling <tt class="docutils literal">typeref:</tt> with "typename:int",
ctags has to analyze "Callable[[int], int]" deeper. We don't want to do so.</p>
</div>
</div>
<div class="section" id="see-also">
<h1>SEE ALSO</h1>
<p>ctags(1), ctags-client-tools(7), ctags-lang-iPythonCell(7)</p>
</div>
</div>
</body>
</html>
|
