diff options
Diffstat (limited to 'vendor/github.com/davecgh/go-spew/spew/format.go')
-rw-r--r-- | vendor/github.com/davecgh/go-spew/spew/format.go | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/vendor/github.com/davecgh/go-spew/spew/format.go b/vendor/github.com/davecgh/go-spew/spew/format.go new file mode 100644 index 0000000..c49875b --- /dev/null +++ b/vendor/github.com/davecgh/go-spew/spew/format.go | |||
@@ -0,0 +1,419 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2013-2016 Dave Collins <dave@davec.name> | ||
3 | * | ||
4 | * Permission to use, copy, modify, and distribute this software for any | ||
5 | * purpose with or without fee is hereby granted, provided that the above | ||
6 | * copyright notice and this permission notice appear in all copies. | ||
7 | * | ||
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | ||
9 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | ||
10 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | ||
11 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | ||
12 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | ||
13 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | ||
14 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | ||
15 | */ | ||
16 | |||
17 | package spew | ||
18 | |||
19 | import ( | ||
20 | "bytes" | ||
21 | "fmt" | ||
22 | "reflect" | ||
23 | "strconv" | ||
24 | "strings" | ||
25 | ) | ||
26 | |||
27 | // supportedFlags is a list of all the character flags supported by fmt package. | ||
28 | const supportedFlags = "0-+# " | ||
29 | |||
30 | // formatState implements the fmt.Formatter interface and contains information | ||
31 | // about the state of a formatting operation. The NewFormatter function can | ||
32 | // be used to get a new Formatter which can be used directly as arguments | ||
33 | // in standard fmt package printing calls. | ||
34 | type formatState struct { | ||
35 | value interface{} | ||
36 | fs fmt.State | ||
37 | depth int | ||
38 | pointers map[uintptr]int | ||
39 | ignoreNextType bool | ||
40 | cs *ConfigState | ||
41 | } | ||
42 | |||
43 | // buildDefaultFormat recreates the original format string without precision | ||
44 | // and width information to pass in to fmt.Sprintf in the case of an | ||
45 | // unrecognized type. Unless new types are added to the language, this | ||
46 | // function won't ever be called. | ||
47 | func (f *formatState) buildDefaultFormat() (format string) { | ||
48 | buf := bytes.NewBuffer(percentBytes) | ||
49 | |||
50 | for _, flag := range supportedFlags { | ||
51 | if f.fs.Flag(int(flag)) { | ||
52 | buf.WriteRune(flag) | ||
53 | } | ||
54 | } | ||
55 | |||
56 | buf.WriteRune('v') | ||
57 | |||
58 | format = buf.String() | ||
59 | return format | ||
60 | } | ||
61 | |||
62 | // constructOrigFormat recreates the original format string including precision | ||
63 | // and width information to pass along to the standard fmt package. This allows | ||
64 | // automatic deferral of all format strings this package doesn't support. | ||
65 | func (f *formatState) constructOrigFormat(verb rune) (format string) { | ||
66 | buf := bytes.NewBuffer(percentBytes) | ||
67 | |||
68 | for _, flag := range supportedFlags { | ||
69 | if f.fs.Flag(int(flag)) { | ||
70 | buf.WriteRune(flag) | ||
71 | } | ||
72 | } | ||
73 | |||
74 | if width, ok := f.fs.Width(); ok { | ||
75 | buf.WriteString(strconv.Itoa(width)) | ||
76 | } | ||
77 | |||
78 | if precision, ok := f.fs.Precision(); ok { | ||
79 | buf.Write(precisionBytes) | ||
80 | buf.WriteString(strconv.Itoa(precision)) | ||
81 | } | ||
82 | |||
83 | buf.WriteRune(verb) | ||
84 | |||
85 | format = buf.String() | ||
86 | return format | ||
87 | } | ||
88 | |||
89 | // unpackValue returns values inside of non-nil interfaces when possible and | ||
90 | // ensures that types for values which have been unpacked from an interface | ||
91 | // are displayed when the show types flag is also set. | ||
92 | // This is useful for data types like structs, arrays, slices, and maps which | ||
93 | // can contain varying types packed inside an interface. | ||
94 | func (f *formatState) unpackValue(v reflect.Value) reflect.Value { | ||
95 | if v.Kind() == reflect.Interface { | ||
96 | f.ignoreNextType = false | ||
97 | if !v.IsNil() { | ||
98 | v = v.Elem() | ||
99 | } | ||
100 | } | ||
101 | return v | ||
102 | } | ||
103 | |||
104 | // formatPtr handles formatting of pointers by indirecting them as necessary. | ||
105 | func (f *formatState) formatPtr(v reflect.Value) { | ||
106 | // Display nil if top level pointer is nil. | ||
107 | showTypes := f.fs.Flag('#') | ||
108 | if v.IsNil() && (!showTypes || f.ignoreNextType) { | ||
109 | f.fs.Write(nilAngleBytes) | ||
110 | return | ||
111 | } | ||
112 | |||
113 | // Remove pointers at or below the current depth from map used to detect | ||
114 | // circular refs. | ||
115 | for k, depth := range f.pointers { | ||
116 | if depth >= f.depth { | ||
117 | delete(f.pointers, k) | ||
118 | } | ||
119 | } | ||
120 | |||
121 | // Keep list of all dereferenced pointers to possibly show later. | ||
122 | pointerChain := make([]uintptr, 0) | ||
123 | |||
124 | // Figure out how many levels of indirection there are by derferencing | ||
125 | // pointers and unpacking interfaces down the chain while detecting circular | ||
126 | // references. | ||
127 | nilFound := false | ||
128 | cycleFound := false | ||
129 | indirects := 0 | ||
130 | ve := v | ||
131 | for ve.Kind() == reflect.Ptr { | ||
132 | if ve.IsNil() { | ||
133 | nilFound = true | ||
134 | break | ||
135 | } | ||
136 | indirects++ | ||
137 | addr := ve.Pointer() | ||
138 | pointerChain = append(pointerChain, addr) | ||
139 | if pd, ok := f.pointers[addr]; ok && pd < f.depth { | ||
140 | cycleFound = true | ||
141 | indirects-- | ||
142 | break | ||
143 | } | ||
144 | f.pointers[addr] = f.depth | ||
145 | |||
146 | ve = ve.Elem() | ||
147 | if ve.Kind() == reflect.Interface { | ||
148 | if ve.IsNil() { | ||
149 | nilFound = true | ||
150 | break | ||
151 | } | ||
152 | ve = ve.Elem() | ||
153 | } | ||
154 | } | ||
155 | |||
156 | // Display type or indirection level depending on flags. | ||
157 | if showTypes && !f.ignoreNextType { | ||
158 | f.fs.Write(openParenBytes) | ||
159 | f.fs.Write(bytes.Repeat(asteriskBytes, indirects)) | ||
160 | f.fs.Write([]byte(ve.Type().String())) | ||
161 | f.fs.Write(closeParenBytes) | ||
162 | } else { | ||
163 | if nilFound || cycleFound { | ||
164 | indirects += strings.Count(ve.Type().String(), "*") | ||
165 | } | ||
166 | f.fs.Write(openAngleBytes) | ||
167 | f.fs.Write([]byte(strings.Repeat("*", indirects))) | ||
168 | f.fs.Write(closeAngleBytes) | ||
169 | } | ||
170 | |||
171 | // Display pointer information depending on flags. | ||
172 | if f.fs.Flag('+') && (len(pointerChain) > 0) { | ||
173 | f.fs.Write(openParenBytes) | ||
174 | for i, addr := range pointerChain { | ||
175 | if i > 0 { | ||
176 | f.fs.Write(pointerChainBytes) | ||
177 | } | ||
178 | printHexPtr(f.fs, addr) | ||
179 | } | ||
180 | f.fs.Write(closeParenBytes) | ||
181 | } | ||
182 | |||
183 | // Display dereferenced value. | ||
184 | switch { | ||
185 | case nilFound == true: | ||
186 | f.fs.Write(nilAngleBytes) | ||
187 | |||
188 | case cycleFound == true: | ||
189 | f.fs.Write(circularShortBytes) | ||
190 | |||
191 | default: | ||
192 | f.ignoreNextType = true | ||
193 | f.format(ve) | ||
194 | } | ||
195 | } | ||
196 | |||
197 | // format is the main workhorse for providing the Formatter interface. It | ||
198 | // uses the passed reflect value to figure out what kind of object we are | ||
199 | // dealing with and formats it appropriately. It is a recursive function, | ||
200 | // however circular data structures are detected and handled properly. | ||
201 | func (f *formatState) format(v reflect.Value) { | ||
202 | // Handle invalid reflect values immediately. | ||
203 | kind := v.Kind() | ||
204 | if kind == reflect.Invalid { | ||
205 | f.fs.Write(invalidAngleBytes) | ||
206 | return | ||
207 | } | ||
208 | |||
209 | // Handle pointers specially. | ||
210 | if kind == reflect.Ptr { | ||
211 | f.formatPtr(v) | ||
212 | return | ||
213 | } | ||
214 | |||
215 | // Print type information unless already handled elsewhere. | ||
216 | if !f.ignoreNextType && f.fs.Flag('#') { | ||
217 | f.fs.Write(openParenBytes) | ||
218 | f.fs.Write([]byte(v.Type().String())) | ||
219 | f.fs.Write(closeParenBytes) | ||
220 | } | ||
221 | f.ignoreNextType = false | ||
222 | |||
223 | // Call Stringer/error interfaces if they exist and the handle methods | ||
224 | // flag is enabled. | ||
225 | if !f.cs.DisableMethods { | ||
226 | if (kind != reflect.Invalid) && (kind != reflect.Interface) { | ||
227 | if handled := handleMethods(f.cs, f.fs, v); handled { | ||
228 | return | ||
229 | } | ||
230 | } | ||
231 | } | ||
232 | |||
233 | switch kind { | ||
234 | case reflect.Invalid: | ||
235 | // Do nothing. We should never get here since invalid has already | ||
236 | // been handled above. | ||
237 | |||
238 | case reflect.Bool: | ||
239 | printBool(f.fs, v.Bool()) | ||
240 | |||
241 | case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int: | ||
242 | printInt(f.fs, v.Int(), 10) | ||
243 | |||
244 | case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint: | ||
245 | printUint(f.fs, v.Uint(), 10) | ||
246 | |||
247 | case reflect.Float32: | ||
248 | printFloat(f.fs, v.Float(), 32) | ||
249 | |||
250 | case reflect.Float64: | ||
251 | printFloat(f.fs, v.Float(), 64) | ||
252 | |||
253 | case reflect.Complex64: | ||
254 | printComplex(f.fs, v.Complex(), 32) | ||
255 | |||
256 | case reflect.Complex128: | ||
257 | printComplex(f.fs, v.Complex(), 64) | ||
258 | |||
259 | case reflect.Slice: | ||
260 | if v.IsNil() { | ||
261 | f.fs.Write(nilAngleBytes) | ||
262 | break | ||
263 | } | ||
264 | fallthrough | ||
265 | |||
266 | case reflect.Array: | ||
267 | f.fs.Write(openBracketBytes) | ||
268 | f.depth++ | ||
269 | if (f.cs.MaxDepth != 0) && (f.depth > f.cs.MaxDepth) { | ||
270 | f.fs.Write(maxShortBytes) | ||
271 | } else { | ||
272 | numEntries := v.Len() | ||
273 | for i := 0; i < numEntries; i++ { | ||
274 | if i > 0 { | ||
275 | f.fs.Write(spaceBytes) | ||
276 | } | ||
277 | f.ignoreNextType = true | ||
278 | f.format(f.unpackValue(v.Index(i))) | ||
279 | } | ||
280 | } | ||
281 | f.depth-- | ||
282 | f.fs.Write(closeBracketBytes) | ||
283 | |||
284 | case reflect.String: | ||
285 | f.fs.Write([]byte(v.String())) | ||
286 | |||
287 | case reflect.Interface: | ||
288 | // The only time we should get here is for nil interfaces due to | ||
289 | // unpackValue calls. | ||
290 | if v.IsNil() { | ||
291 | f.fs.Write(nilAngleBytes) | ||
292 | } | ||
293 | |||
294 | case reflect.Ptr: | ||
295 | // Do nothing. We should never get here since pointers have already | ||
296 | // been handled above. | ||
297 | |||
298 | case reflect.Map: | ||
299 | // nil maps should be indicated as different than empty maps | ||
300 | if v.IsNil() { | ||
301 | f.fs.Write(nilAngleBytes) | ||
302 | break | ||
303 | } | ||
304 | |||
305 | f.fs.Write(openMapBytes) | ||
306 | f.depth++ | ||
307 | if (f.cs.MaxDepth != 0) && (f.depth > f.cs.MaxDepth) { | ||
308 | f.fs.Write(maxShortBytes) | ||
309 | } else { | ||
310 | keys := v.MapKeys() | ||
311 | if f.cs.SortKeys { | ||
312 | sortValues(keys, f.cs) | ||
313 | } | ||
314 | for i, key := range keys { | ||
315 | if i > 0 { | ||
316 | f.fs.Write(spaceBytes) | ||
317 | } | ||
318 | f.ignoreNextType = true | ||
319 | f.format(f.unpackValue(key)) | ||
320 | f.fs.Write(colonBytes) | ||
321 | f.ignoreNextType = true | ||
322 | f.format(f.unpackValue(v.MapIndex(key))) | ||
323 | } | ||
324 | } | ||
325 | f.depth-- | ||
326 | f.fs.Write(closeMapBytes) | ||
327 | |||
328 | case reflect.Struct: | ||
329 | numFields := v.NumField() | ||
330 | f.fs.Write(openBraceBytes) | ||
331 | f.depth++ | ||
332 | if (f.cs.MaxDepth != 0) && (f.depth > f.cs.MaxDepth) { | ||
333 | f.fs.Write(maxShortBytes) | ||
334 | } else { | ||
335 | vt := v.Type() | ||
336 | for i := 0; i < numFields; i++ { | ||
337 | if i > 0 { | ||
338 | f.fs.Write(spaceBytes) | ||
339 | } | ||
340 | vtf := vt.Field(i) | ||
341 | if f.fs.Flag('+') || f.fs.Flag('#') { | ||
342 | f.fs.Write([]byte(vtf.Name)) | ||
343 | f.fs.Write(colonBytes) | ||
344 | } | ||
345 | f.format(f.unpackValue(v.Field(i))) | ||
346 | } | ||
347 | } | ||
348 | f.depth-- | ||
349 | f.fs.Write(closeBraceBytes) | ||
350 | |||
351 | case reflect.Uintptr: | ||
352 | printHexPtr(f.fs, uintptr(v.Uint())) | ||
353 | |||
354 | case reflect.UnsafePointer, reflect.Chan, reflect.Func: | ||
355 | printHexPtr(f.fs, v.Pointer()) | ||
356 | |||
357 | // There were not any other types at the time this code was written, but | ||
358 | // fall back to letting the default fmt package handle it if any get added. | ||
359 | default: | ||
360 | format := f.buildDefaultFormat() | ||
361 | if v.CanInterface() { | ||
362 | fmt.Fprintf(f.fs, format, v.Interface()) | ||
363 | } else { | ||
364 | fmt.Fprintf(f.fs, format, v.String()) | ||
365 | } | ||
366 | } | ||
367 | } | ||
368 | |||
369 | // Format satisfies the fmt.Formatter interface. See NewFormatter for usage | ||
370 | // details. | ||
371 | func (f *formatState) Format(fs fmt.State, verb rune) { | ||
372 | f.fs = fs | ||
373 | |||
374 | // Use standard formatting for verbs that are not v. | ||
375 | if verb != 'v' { | ||
376 | format := f.constructOrigFormat(verb) | ||
377 | fmt.Fprintf(fs, format, f.value) | ||
378 | return | ||
379 | } | ||
380 | |||
381 | if f.value == nil { | ||
382 | if fs.Flag('#') { | ||
383 | fs.Write(interfaceBytes) | ||
384 | } | ||
385 | fs.Write(nilAngleBytes) | ||
386 | return | ||
387 | } | ||
388 | |||
389 | f.format(reflect.ValueOf(f.value)) | ||
390 | } | ||
391 | |||
392 | // newFormatter is a helper function to consolidate the logic from the various | ||
393 | // public methods which take varying config states. | ||
394 | func newFormatter(cs *ConfigState, v interface{}) fmt.Formatter { | ||
395 | fs := &formatState{value: v, cs: cs} | ||
396 | fs.pointers = make(map[uintptr]int) | ||
397 | return fs | ||
398 | } | ||
399 | |||
400 | /* | ||
401 | NewFormatter returns a custom formatter that satisfies the fmt.Formatter | ||
402 | interface. As a result, it integrates cleanly with standard fmt package | ||
403 | printing functions. The formatter is useful for inline printing of smaller data | ||
404 | types similar to the standard %v format specifier. | ||
405 | |||
406 | The custom formatter only responds to the %v (most compact), %+v (adds pointer | ||
407 | addresses), %#v (adds types), or %#+v (adds types and pointer addresses) verb | ||
408 | combinations. Any other verbs such as %x and %q will be sent to the the | ||
409 | standard fmt package for formatting. In addition, the custom formatter ignores | ||
410 | the width and precision arguments (however they will still work on the format | ||
411 | specifiers not handled by the custom formatter). | ||
412 | |||
413 | Typically this function shouldn't be called directly. It is much easier to make | ||
414 | use of the custom formatter by calling one of the convenience functions such as | ||
415 | Printf, Println, or Fprintf. | ||
416 | */ | ||
417 | func NewFormatter(v interface{}) fmt.Formatter { | ||
418 | return newFormatter(&Config, v) | ||
419 | } | ||