xref: /freebsd/contrib/libxo/doc/xolint.rst (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1'A percent sign appearing in text is a literal'
2+++++++++++++++++++++++++++++++++++++++++++++++
3
4The message "A percent sign appearing in text is a literal" can be caused by code like:
5
6::
7
8    xo_emit("cost: %d", cost);
9
10This code should be replaced with code like:
11
12::
13
14    xo_emit("{L:cost}: {:cost/%d}", cost);
15
16This can be a bit surprising and could be a field that was not
17properly converted to a libxo-style format string.
18
19
20'Unknown long name for role/modifier'
21+++++++++++++++++++++++++++++++++++++
22
23The message "Unknown long name for role/modifier" can be caused by code like:
24
25::
26
27    xo_emit("{,humanization:value}", value);
28
29This code should be replaced with code like:
30
31::
32
33    xo_emit("{,humanize:value}", value);
34
35The hn-* modifiers (hn-decimal, hn-space, hn-1000)
36are only valid for fields with the {h:} modifier.
37
38
39'Last character before field definition is a field type'
40++++++++++++++++++++++++++++++++++++++++++++++++++++++++
41
42The message "Last character before field definition is a field type" can be caused by code like:
43A common typo:
44
45::
46
47    xo_emit("{T:Min} T{:Max}");
48
49This code should be replaced with code like:
50
51::
52
53    xo_emit("{T:Min} {T:Max}");
54
55Twiddling the "{" and the field role is a common typo.
56
57
58'Encoding format uses different number of arguments'
59++++++++++++++++++++++++++++++++++++++++++++++++++++
60
61The message "Encoding format uses different number of arguments" can be caused by code like:
62
63::
64
65    xo_emit("{:name/%6.6s %%04d/%s}", name, number);
66
67This code should be replaced with code like:
68
69::
70
71    xo_emit("{:name/%6.6s %04d/%s-%d}", name, number);
72
73Both format should consume the same number of arguments off the stack
74
75
76'Only one field role can be used'
77+++++++++++++++++++++++++++++++++
78
79The message "Only one field role can be used" can be caused by code like:
80
81::
82
83    xo_emit("{LT:Max}");
84
85This code should be replaced with code like:
86
87::
88
89    xo_emit("{T:Max}");
90
91'Potential missing slash after C, D, N, L, or T with format'
92++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
93
94The message "Potential missing slash after C, D, N, L, or T with format" can be caused by code like:
95
96::
97
98    xo_emit("{T:%6.6s}\n", "Max");
99
100This code should be replaced with code like:
101
102::
103
104    xo_emit("{T:/%6.6s}\n", "Max");
105
106The "%6.6s" will be a literal, not a field format.  While
107it's possibly valid, it's likely a missing "/".
108
109
110'An encoding format cannot be given (roles: DNLT)'
111++++++++++++++++++++++++++++++++++++++++++++++++++
112
113The message "An encoding format cannot be given (roles: DNLT)" can be caused by code like:
114
115::
116
117    xo_emit("{T:Max//%s}", "Max");
118
119Fields with the C, D, N, L, and T roles are not emitted in
120the 'encoding' style (JSON, XML), so an encoding format
121would make no sense.
122
123
124'Format cannot be given when content is present (roles: CDLN)'
125++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
126
127The message "Format cannot be given when content is present (roles: CDLN)" can be caused by code like:
128
129::
130
131    xo_emit("{N:Max/%6.6s}", "Max");
132
133Fields with the C, D, L, or N roles can't have both
134static literal content ("{L:Label}") and a
135format ("{L:/%s}").
136This error will also occur when the content has a backslash
137in it, like "{N:Type of I/O}"; backslashes should be escaped,
138like "{N:Type of I\\/O}".  Note the double backslash, one for
139handling 'C' strings, and one for libxo.
140
141
142'Field has color without fg- or bg- (role: C)'
143++++++++++++++++++++++++++++++++++++++++++++++
144
145The message "Field has color without fg- or bg- (role: C)" can be caused by code like:
146
147::
148
149    xo_emit("{C:green}{:foo}{C:}", x);
150
151This code should be replaced with code like:
152
153::
154
155    xo_emit("{C:fg-green}{:foo}{C:}", x);
156
157Colors must be prefixed by either "fg-" or "bg-".
158
159
160'Field has invalid color or effect (role: C)'
161+++++++++++++++++++++++++++++++++++++++++++++
162
163The message "Field has invalid color or effect (role: C)" can be caused by code like:
164
165::
166
167    xo_emit("{C:fg-purple,bold}{:foo}{C:gween}", x);
168
169This code should be replaced with code like:
170
171::
172
173    xo_emit("{C:fg-red,bold}{:foo}{C:fg-green}", x);
174
175The list of colors and effects are limited.  The
176set of colors includes default, black, red, green,
177yellow, blue, magenta, cyan, and white, which must
178be prefixed by either "fg-" or "bg-".  Effects are
179limited to bold, no-bold, underline, no-underline,
180inverse, no-inverse, normal, and reset.  Values must
181be separated by commas.
182
183
184'Field has humanize modifier but no format string'
185++++++++++++++++++++++++++++++++++++++++++++++++++
186
187The message "Field has humanize modifier but no format string" can be caused by code like:
188
189::
190
191    xo_emit("{h:value}", value);
192
193This code should be replaced with code like:
194
195::
196
197    xo_emit("{h:value/%d}", value);
198
199Humanization is only value for numbers, which are not
200likely to use the default format ("%s").
201
202
203'Field has hn-* modifier but not 'h' modifier'
204++++++++++++++++++++++++++++++++++++++++++++++
205
206The message "Field has hn-* modifier but not 'h' modifier" can be caused by code like:
207
208::
209
210    xo_emit("{,hn-1000:value}", value);
211
212This code should be replaced with code like:
213
214::
215
216    xo_emit("{h,hn-1000:value}", value);
217
218The hn-* modifiers (hn-decimal, hn-space, hn-1000)
219are only valid for fields with the {h:} modifier.
220
221
222'Value field must have a name (as content)")'
223+++++++++++++++++++++++++++++++++++++++++++++
224
225The message "Value field must have a name (as content)")" can be caused by code like:
226
227::
228
229    xo_emit("{:/%s}", "value");
230
231This code should be replaced with code like:
232
233::
234
235    xo_emit("{:tag-name/%s}", "value");
236
237The field name is used for XML and JSON encodings.  These
238tags names are static and must appear directly in the
239field descriptor.
240
241
242'Use hyphens, not underscores, for value field name'
243++++++++++++++++++++++++++++++++++++++++++++++++++++
244
245The message "Use hyphens, not underscores, for value field name" can be caused by code like:
246
247::
248
249    xo_emit("{:no_under_scores}", "bad");
250
251This code should be replaced with code like:
252
253::
254
255    xo_emit("{:no-under-scores}", "bad");
256
257Use of hyphens is traditional in XML, and the XOF_UNDERSCORES
258flag can be used to generate underscores in JSON, if desired.
259But the raw field name should use hyphens.
260
261
262'Value field name cannot start with digit'
263++++++++++++++++++++++++++++++++++++++++++
264
265The message "Value field name cannot start with digit" can be caused by code like:
266
267::
268
269    xo_emit("{:10-gig/}");
270
271This code should be replaced with code like:
272
273::
274
275    xo_emit("{:ten-gig/}");
276
277XML element names cannot start with a digit.
278
279
280'Value field name should be lower case'
281+++++++++++++++++++++++++++++++++++++++
282
283The message "Value field name should be lower case" can be caused by code like:
284
285::
286
287    xo_emit("{:WHY-ARE-YOU-SHOUTING}", "NO REASON");
288
289This code should be replaced with code like:
290
291::
292
293    xo_emit("{:why-are-you-shouting}", "no reason");
294
295Lower case is more civilized.  Even TLAs should be lower case
296to avoid scenarios where the differences between "XPath" and
297"Xpath" drive your users crazy.  Lower case rules the seas.
298
299
300'Value field name should be longer than two characters'
301+++++++++++++++++++++++++++++++++++++++++++++++++++++++
302
303The message "Value field name should be longer than two characters" can be caused by code like:
304
305::
306
307    xo_emit("{:x}", "mumble");
308
309This code should be replaced with code like:
310
311::
312
313    xo_emit("{:something-meaningful}", "mumble");
314
315Field names should be descriptive, and it's hard to
316be descriptive in less than two characters.  Consider
317your users and try to make something more useful.
318Note that this error often occurs when the field type
319is placed after the colon ("{:T/%20s}"), instead of before
320it ("{T:/20s}").
321
322
323'Value field name contains invalid character'
324+++++++++++++++++++++++++++++++++++++++++++++
325
326The message "Value field name contains invalid character" can be caused by code like:
327
328::
329
330    xo_emit("{:cost-in-$$/%u}", 15);
331
332This code should be replaced with code like:
333
334::
335
336    xo_emit("{:cost-in-dollars/%u}", 15);
337
338An invalid character is often a sign of a typo, like "{:]}"
339instead of "{]:}".  Field names are restricted to lower-case
340characters, digits, and hyphens.
341
342
343'decoration field contains invalid character'
344+++++++++++++++++++++++++++++++++++++++++++++
345
346The message "decoration field contains invalid character" can be caused by code like:
347
348::
349
350    xo_emit("{D:not good}");
351
352This code should be replaced with code like:
353
354::
355
356    xo_emit("{D:((}{:good}{D:))}", "yes");
357
358This is minor, but fields should use proper roles.  Decoration
359fields are meant to hold punctuation and other characters used
360to decorate the content, typically to make it more readable
361to human readers.
362
363
364'Anchor content should be decimal width'
365++++++++++++++++++++++++++++++++++++++++
366
367The message "Anchor content should be decimal width" can be caused by code like:
368
369::
370
371    xo_emit("{[:mumble}");
372
373This code should be replaced with code like:
374
375::
376
377    xo_emit("{[:32}");
378
379Anchors need an integer value to specify the width of
380the set of anchored fields.  The value can be positive
381(for left padding/right justification) or negative (for
382right padding/left justification) and can appear in
383either the start or stop anchor field descriptor.
384
385
386'Anchor format should be "%d"'
387++++++++++++++++++++++++++++++
388
389The message "Anchor format should be "%d"" can be caused by code like:
390
391::
392
393    xo_emit("{[:/%s}");
394
395This code should be replaced with code like:
396
397::
398
399    xo_emit("{[:/%d}");
400
401Anchors only grok integer values, and if the value is not static,
402if must be in an 'int' argument, represented by the "%d" format.
403Anything else is an error.
404
405
406'Anchor cannot have both format and encoding format")'
407++++++++++++++++++++++++++++++++++++++++++++++++++++++
408
409The message "Anchor cannot have both format and encoding format")" can be caused by code like:
410
411::
412
413    xo_emit("{[:32/%d}");
414
415This code should be replaced with code like:
416
417::
418
419    xo_emit("{[:32}");
420
421Anchors can have a static value or argument for the width,
422but cannot have both.
423
424
425'Max width only valid for strings'
426++++++++++++++++++++++++++++++++++
427
428The message "Max width only valid for strings" can be caused by code like:
429
430::
431
432    xo_emit("{:tag/%2.4.6d}", 55);
433
434This code should be replaced with code like:
435
436::
437
438    xo_emit("{:tag/%2.6d}", 55);
439
440libxo allows a true 'max width' in addition to the traditional
441printf-style 'max number of bytes to use for input'.  But this
442is supported only for string values, since it makes no sense
443for non-strings.  This error may occur from a typo,
444like "{:tag/%6..6d}" where only one period should be used.
445