Colin Cross | 7bb052a | 2015-02-03 12:59:37 -0800 | [diff] [blame^] | 1 | // Copyright 2010 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package time |
| 6 | |
| 7 | import "errors" |
| 8 | |
| 9 | // These are predefined layouts for use in Time.Format and Time.Parse. |
| 10 | // The reference time used in the layouts is the specific time: |
| 11 | // Mon Jan 2 15:04:05 MST 2006 |
| 12 | // which is Unix time 1136239445. Since MST is GMT-0700, |
| 13 | // the reference time can be thought of as |
| 14 | // 01/02 03:04:05PM '06 -0700 |
| 15 | // To define your own format, write down what the reference time would look |
| 16 | // like formatted your way; see the values of constants like ANSIC, |
| 17 | // StampMicro or Kitchen for examples. The model is to demonstrate what the |
| 18 | // reference time looks like so that the Format and Parse methods can apply |
| 19 | // the same transformation to a general time value. |
| 20 | // |
| 21 | // Within the format string, an underscore _ represents a space that may be |
| 22 | // replaced by a digit if the following number (a day) has two digits; for |
| 23 | // compatibility with fixed-width Unix time formats. |
| 24 | // |
| 25 | // A decimal point followed by one or more zeros represents a fractional |
| 26 | // second, printed to the given number of decimal places. A decimal point |
| 27 | // followed by one or more nines represents a fractional second, printed to |
| 28 | // the given number of decimal places, with trailing zeros removed. |
| 29 | // When parsing (only), the input may contain a fractional second |
| 30 | // field immediately after the seconds field, even if the layout does not |
| 31 | // signify its presence. In that case a decimal point followed by a maximal |
| 32 | // series of digits is parsed as a fractional second. |
| 33 | // |
| 34 | // Numeric time zone offsets format as follows: |
| 35 | // -0700 ±hhmm |
| 36 | // -07:00 ±hh:mm |
| 37 | // Replacing the sign in the format with a Z triggers |
| 38 | // the ISO 8601 behavior of printing Z instead of an |
| 39 | // offset for the UTC zone. Thus: |
| 40 | // Z0700 Z or ±hhmm |
| 41 | // Z07:00 Z or ±hh:mm |
| 42 | const ( |
| 43 | ANSIC = "Mon Jan _2 15:04:05 2006" |
| 44 | UnixDate = "Mon Jan _2 15:04:05 MST 2006" |
| 45 | RubyDate = "Mon Jan 02 15:04:05 -0700 2006" |
| 46 | RFC822 = "02 Jan 06 15:04 MST" |
| 47 | RFC822Z = "02 Jan 06 15:04 -0700" // RFC822 with numeric zone |
| 48 | RFC850 = "Monday, 02-Jan-06 15:04:05 MST" |
| 49 | RFC1123 = "Mon, 02 Jan 2006 15:04:05 MST" |
| 50 | RFC1123Z = "Mon, 02 Jan 2006 15:04:05 -0700" // RFC1123 with numeric zone |
| 51 | RFC3339 = "2006-01-02T15:04:05Z07:00" |
| 52 | RFC3339Nano = "2006-01-02T15:04:05.999999999Z07:00" |
| 53 | Kitchen = "3:04PM" |
| 54 | // Handy time stamps. |
| 55 | Stamp = "Jan _2 15:04:05" |
| 56 | StampMilli = "Jan _2 15:04:05.000" |
| 57 | StampMicro = "Jan _2 15:04:05.000000" |
| 58 | StampNano = "Jan _2 15:04:05.000000000" |
| 59 | ) |
| 60 | |
| 61 | const ( |
| 62 | _ = iota |
| 63 | stdLongMonth = iota + stdNeedDate // "January" |
| 64 | stdMonth // "Jan" |
| 65 | stdNumMonth // "1" |
| 66 | stdZeroMonth // "01" |
| 67 | stdLongWeekDay // "Monday" |
| 68 | stdWeekDay // "Mon" |
| 69 | stdDay // "2" |
| 70 | stdUnderDay // "_2" |
| 71 | stdZeroDay // "02" |
| 72 | stdHour = iota + stdNeedClock // "15" |
| 73 | stdHour12 // "3" |
| 74 | stdZeroHour12 // "03" |
| 75 | stdMinute // "4" |
| 76 | stdZeroMinute // "04" |
| 77 | stdSecond // "5" |
| 78 | stdZeroSecond // "05" |
| 79 | stdLongYear = iota + stdNeedDate // "2006" |
| 80 | stdYear // "06" |
| 81 | stdPM = iota + stdNeedClock // "PM" |
| 82 | stdpm // "pm" |
| 83 | stdTZ = iota // "MST" |
| 84 | stdISO8601TZ // "Z0700" // prints Z for UTC |
| 85 | stdISO8601SecondsTZ // "Z070000" |
| 86 | stdISO8601ColonTZ // "Z07:00" // prints Z for UTC |
| 87 | stdISO8601ColonSecondsTZ // "Z07:00:00" |
| 88 | stdNumTZ // "-0700" // always numeric |
| 89 | stdNumSecondsTz // "-070000" |
| 90 | stdNumShortTZ // "-07" // always numeric |
| 91 | stdNumColonTZ // "-07:00" // always numeric |
| 92 | stdNumColonSecondsTZ // "-07:00:00" |
| 93 | stdFracSecond0 // ".0", ".00", ... , trailing zeros included |
| 94 | stdFracSecond9 // ".9", ".99", ..., trailing zeros omitted |
| 95 | |
| 96 | stdNeedDate = 1 << 8 // need month, day, year |
| 97 | stdNeedClock = 2 << 8 // need hour, minute, second |
| 98 | stdArgShift = 16 // extra argument in high bits, above low stdArgShift |
| 99 | stdMask = 1<<stdArgShift - 1 // mask out argument |
| 100 | ) |
| 101 | |
| 102 | // std0x records the std values for "01", "02", ..., "06". |
| 103 | var std0x = [...]int{stdZeroMonth, stdZeroDay, stdZeroHour12, stdZeroMinute, stdZeroSecond, stdYear} |
| 104 | |
| 105 | // startsWithLowerCase reports whether the string has a lower-case letter at the beginning. |
| 106 | // Its purpose is to prevent matching strings like "Month" when looking for "Mon". |
| 107 | func startsWithLowerCase(str string) bool { |
| 108 | if len(str) == 0 { |
| 109 | return false |
| 110 | } |
| 111 | c := str[0] |
| 112 | return 'a' <= c && c <= 'z' |
| 113 | } |
| 114 | |
| 115 | // nextStdChunk finds the first occurrence of a std string in |
| 116 | // layout and returns the text before, the std string, and the text after. |
| 117 | func nextStdChunk(layout string) (prefix string, std int, suffix string) { |
| 118 | for i := 0; i < len(layout); i++ { |
| 119 | switch c := int(layout[i]); c { |
| 120 | case 'J': // January, Jan |
| 121 | if len(layout) >= i+3 && layout[i:i+3] == "Jan" { |
| 122 | if len(layout) >= i+7 && layout[i:i+7] == "January" { |
| 123 | return layout[0:i], stdLongMonth, layout[i+7:] |
| 124 | } |
| 125 | if !startsWithLowerCase(layout[i+3:]) { |
| 126 | return layout[0:i], stdMonth, layout[i+3:] |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | case 'M': // Monday, Mon, MST |
| 131 | if len(layout) >= i+3 { |
| 132 | if layout[i:i+3] == "Mon" { |
| 133 | if len(layout) >= i+6 && layout[i:i+6] == "Monday" { |
| 134 | return layout[0:i], stdLongWeekDay, layout[i+6:] |
| 135 | } |
| 136 | if !startsWithLowerCase(layout[i+3:]) { |
| 137 | return layout[0:i], stdWeekDay, layout[i+3:] |
| 138 | } |
| 139 | } |
| 140 | if layout[i:i+3] == "MST" { |
| 141 | return layout[0:i], stdTZ, layout[i+3:] |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | case '0': // 01, 02, 03, 04, 05, 06 |
| 146 | if len(layout) >= i+2 && '1' <= layout[i+1] && layout[i+1] <= '6' { |
| 147 | return layout[0:i], std0x[layout[i+1]-'1'], layout[i+2:] |
| 148 | } |
| 149 | |
| 150 | case '1': // 15, 1 |
| 151 | if len(layout) >= i+2 && layout[i+1] == '5' { |
| 152 | return layout[0:i], stdHour, layout[i+2:] |
| 153 | } |
| 154 | return layout[0:i], stdNumMonth, layout[i+1:] |
| 155 | |
| 156 | case '2': // 2006, 2 |
| 157 | if len(layout) >= i+4 && layout[i:i+4] == "2006" { |
| 158 | return layout[0:i], stdLongYear, layout[i+4:] |
| 159 | } |
| 160 | return layout[0:i], stdDay, layout[i+1:] |
| 161 | |
| 162 | case '_': // _2 |
| 163 | if len(layout) >= i+2 && layout[i+1] == '2' { |
| 164 | return layout[0:i], stdUnderDay, layout[i+2:] |
| 165 | } |
| 166 | |
| 167 | case '3': |
| 168 | return layout[0:i], stdHour12, layout[i+1:] |
| 169 | |
| 170 | case '4': |
| 171 | return layout[0:i], stdMinute, layout[i+1:] |
| 172 | |
| 173 | case '5': |
| 174 | return layout[0:i], stdSecond, layout[i+1:] |
| 175 | |
| 176 | case 'P': // PM |
| 177 | if len(layout) >= i+2 && layout[i+1] == 'M' { |
| 178 | return layout[0:i], stdPM, layout[i+2:] |
| 179 | } |
| 180 | |
| 181 | case 'p': // pm |
| 182 | if len(layout) >= i+2 && layout[i+1] == 'm' { |
| 183 | return layout[0:i], stdpm, layout[i+2:] |
| 184 | } |
| 185 | |
| 186 | case '-': // -070000, -07:00:00, -0700, -07:00, -07 |
| 187 | if len(layout) >= i+7 && layout[i:i+7] == "-070000" { |
| 188 | return layout[0:i], stdNumSecondsTz, layout[i+7:] |
| 189 | } |
| 190 | if len(layout) >= i+9 && layout[i:i+9] == "-07:00:00" { |
| 191 | return layout[0:i], stdNumColonSecondsTZ, layout[i+9:] |
| 192 | } |
| 193 | if len(layout) >= i+5 && layout[i:i+5] == "-0700" { |
| 194 | return layout[0:i], stdNumTZ, layout[i+5:] |
| 195 | } |
| 196 | if len(layout) >= i+6 && layout[i:i+6] == "-07:00" { |
| 197 | return layout[0:i], stdNumColonTZ, layout[i+6:] |
| 198 | } |
| 199 | if len(layout) >= i+3 && layout[i:i+3] == "-07" { |
| 200 | return layout[0:i], stdNumShortTZ, layout[i+3:] |
| 201 | } |
| 202 | |
| 203 | case 'Z': // Z070000, Z07:00:00, Z0700, Z07:00, |
| 204 | if len(layout) >= i+7 && layout[i:i+7] == "Z070000" { |
| 205 | return layout[0:i], stdISO8601SecondsTZ, layout[i+7:] |
| 206 | } |
| 207 | if len(layout) >= i+9 && layout[i:i+9] == "Z07:00:00" { |
| 208 | return layout[0:i], stdISO8601ColonSecondsTZ, layout[i+9:] |
| 209 | } |
| 210 | if len(layout) >= i+5 && layout[i:i+5] == "Z0700" { |
| 211 | return layout[0:i], stdISO8601TZ, layout[i+5:] |
| 212 | } |
| 213 | if len(layout) >= i+6 && layout[i:i+6] == "Z07:00" { |
| 214 | return layout[0:i], stdISO8601ColonTZ, layout[i+6:] |
| 215 | } |
| 216 | |
| 217 | case '.': // .000 or .999 - repeated digits for fractional seconds. |
| 218 | if i+1 < len(layout) && (layout[i+1] == '0' || layout[i+1] == '9') { |
| 219 | ch := layout[i+1] |
| 220 | j := i + 1 |
| 221 | for j < len(layout) && layout[j] == ch { |
| 222 | j++ |
| 223 | } |
| 224 | // String of digits must end here - only fractional second is all digits. |
| 225 | if !isDigit(layout, j) { |
| 226 | std := stdFracSecond0 |
| 227 | if layout[i+1] == '9' { |
| 228 | std = stdFracSecond9 |
| 229 | } |
| 230 | std |= (j - (i + 1)) << stdArgShift |
| 231 | return layout[0:i], std, layout[j:] |
| 232 | } |
| 233 | } |
| 234 | } |
| 235 | } |
| 236 | return layout, 0, "" |
| 237 | } |
| 238 | |
| 239 | var longDayNames = []string{ |
| 240 | "Sunday", |
| 241 | "Monday", |
| 242 | "Tuesday", |
| 243 | "Wednesday", |
| 244 | "Thursday", |
| 245 | "Friday", |
| 246 | "Saturday", |
| 247 | } |
| 248 | |
| 249 | var shortDayNames = []string{ |
| 250 | "Sun", |
| 251 | "Mon", |
| 252 | "Tue", |
| 253 | "Wed", |
| 254 | "Thu", |
| 255 | "Fri", |
| 256 | "Sat", |
| 257 | } |
| 258 | |
| 259 | var shortMonthNames = []string{ |
| 260 | "---", |
| 261 | "Jan", |
| 262 | "Feb", |
| 263 | "Mar", |
| 264 | "Apr", |
| 265 | "May", |
| 266 | "Jun", |
| 267 | "Jul", |
| 268 | "Aug", |
| 269 | "Sep", |
| 270 | "Oct", |
| 271 | "Nov", |
| 272 | "Dec", |
| 273 | } |
| 274 | |
| 275 | var longMonthNames = []string{ |
| 276 | "---", |
| 277 | "January", |
| 278 | "February", |
| 279 | "March", |
| 280 | "April", |
| 281 | "May", |
| 282 | "June", |
| 283 | "July", |
| 284 | "August", |
| 285 | "September", |
| 286 | "October", |
| 287 | "November", |
| 288 | "December", |
| 289 | } |
| 290 | |
| 291 | // match returns true if s1 and s2 match ignoring case. |
| 292 | // It is assumed s1 and s2 are the same length. |
| 293 | func match(s1, s2 string) bool { |
| 294 | for i := 0; i < len(s1); i++ { |
| 295 | c1 := s1[i] |
| 296 | c2 := s2[i] |
| 297 | if c1 != c2 { |
| 298 | // Switch to lower-case; 'a'-'A' is known to be a single bit. |
| 299 | c1 |= 'a' - 'A' |
| 300 | c2 |= 'a' - 'A' |
| 301 | if c1 != c2 || c1 < 'a' || c1 > 'z' { |
| 302 | return false |
| 303 | } |
| 304 | } |
| 305 | } |
| 306 | return true |
| 307 | } |
| 308 | |
| 309 | func lookup(tab []string, val string) (int, string, error) { |
| 310 | for i, v := range tab { |
| 311 | if len(val) >= len(v) && match(val[0:len(v)], v) { |
| 312 | return i, val[len(v):], nil |
| 313 | } |
| 314 | } |
| 315 | return -1, val, errBad |
| 316 | } |
| 317 | |
| 318 | // appendUint appends the decimal form of x to b and returns the result. |
| 319 | // If x is a single-digit number and pad != 0, appendUint inserts the pad byte |
| 320 | // before the digit. |
| 321 | // Duplicates functionality in strconv, but avoids dependency. |
| 322 | func appendUint(b []byte, x uint, pad byte) []byte { |
| 323 | if x < 10 { |
| 324 | if pad != 0 { |
| 325 | b = append(b, pad) |
| 326 | } |
| 327 | return append(b, byte('0'+x)) |
| 328 | } |
| 329 | if x < 100 { |
| 330 | b = append(b, byte('0'+x/10)) |
| 331 | b = append(b, byte('0'+x%10)) |
| 332 | return b |
| 333 | } |
| 334 | |
| 335 | var buf [32]byte |
| 336 | n := len(buf) |
| 337 | if x == 0 { |
| 338 | return append(b, '0') |
| 339 | } |
| 340 | for x >= 10 { |
| 341 | n-- |
| 342 | buf[n] = byte(x%10 + '0') |
| 343 | x /= 10 |
| 344 | } |
| 345 | n-- |
| 346 | buf[n] = byte(x + '0') |
| 347 | return append(b, buf[n:]...) |
| 348 | } |
| 349 | |
| 350 | // Never printed, just needs to be non-nil for return by atoi. |
| 351 | var atoiError = errors.New("time: invalid number") |
| 352 | |
| 353 | // Duplicates functionality in strconv, but avoids dependency. |
| 354 | func atoi(s string) (x int, err error) { |
| 355 | neg := false |
| 356 | if s != "" && (s[0] == '-' || s[0] == '+') { |
| 357 | neg = s[0] == '-' |
| 358 | s = s[1:] |
| 359 | } |
| 360 | q, rem, err := leadingInt(s) |
| 361 | x = int(q) |
| 362 | if err != nil || rem != "" { |
| 363 | return 0, atoiError |
| 364 | } |
| 365 | if neg { |
| 366 | x = -x |
| 367 | } |
| 368 | return x, nil |
| 369 | } |
| 370 | |
| 371 | // formatNano appends a fractional second, as nanoseconds, to b |
| 372 | // and returns the result. |
| 373 | func formatNano(b []byte, nanosec uint, n int, trim bool) []byte { |
| 374 | u := nanosec |
| 375 | var buf [9]byte |
| 376 | for start := len(buf); start > 0; { |
| 377 | start-- |
| 378 | buf[start] = byte(u%10 + '0') |
| 379 | u /= 10 |
| 380 | } |
| 381 | |
| 382 | if n > 9 { |
| 383 | n = 9 |
| 384 | } |
| 385 | if trim { |
| 386 | for n > 0 && buf[n-1] == '0' { |
| 387 | n-- |
| 388 | } |
| 389 | if n == 0 { |
| 390 | return b |
| 391 | } |
| 392 | } |
| 393 | b = append(b, '.') |
| 394 | return append(b, buf[:n]...) |
| 395 | } |
| 396 | |
| 397 | // String returns the time formatted using the format string |
| 398 | // "2006-01-02 15:04:05.999999999 -0700 MST" |
| 399 | func (t Time) String() string { |
| 400 | return t.Format("2006-01-02 15:04:05.999999999 -0700 MST") |
| 401 | } |
| 402 | |
| 403 | // Format returns a textual representation of the time value formatted |
| 404 | // according to layout, which defines the format by showing how the reference |
| 405 | // time, defined to be |
| 406 | // Mon Jan 2 15:04:05 -0700 MST 2006 |
| 407 | // would be displayed if it were the value; it serves as an example of the |
| 408 | // desired output. The same display rules will then be applied to the time |
| 409 | // value. |
| 410 | // Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard |
| 411 | // and convenient representations of the reference time. For more information |
| 412 | // about the formats and the definition of the reference time, see the |
| 413 | // documentation for ANSIC and the other constants defined by this package. |
| 414 | func (t Time) Format(layout string) string { |
| 415 | var ( |
| 416 | name, offset, abs = t.locabs() |
| 417 | |
| 418 | year int = -1 |
| 419 | month Month |
| 420 | day int |
| 421 | hour int = -1 |
| 422 | min int |
| 423 | sec int |
| 424 | |
| 425 | b []byte |
| 426 | buf [64]byte |
| 427 | ) |
| 428 | max := len(layout) + 10 |
| 429 | if max <= len(buf) { |
| 430 | b = buf[:0] |
| 431 | } else { |
| 432 | b = make([]byte, 0, max) |
| 433 | } |
| 434 | // Each iteration generates one std value. |
| 435 | for layout != "" { |
| 436 | prefix, std, suffix := nextStdChunk(layout) |
| 437 | if prefix != "" { |
| 438 | b = append(b, prefix...) |
| 439 | } |
| 440 | if std == 0 { |
| 441 | break |
| 442 | } |
| 443 | layout = suffix |
| 444 | |
| 445 | // Compute year, month, day if needed. |
| 446 | if year < 0 && std&stdNeedDate != 0 { |
| 447 | year, month, day, _ = absDate(abs, true) |
| 448 | } |
| 449 | |
| 450 | // Compute hour, minute, second if needed. |
| 451 | if hour < 0 && std&stdNeedClock != 0 { |
| 452 | hour, min, sec = absClock(abs) |
| 453 | } |
| 454 | |
| 455 | switch std & stdMask { |
| 456 | case stdYear: |
| 457 | y := year |
| 458 | if y < 0 { |
| 459 | y = -y |
| 460 | } |
| 461 | b = appendUint(b, uint(y%100), '0') |
| 462 | case stdLongYear: |
| 463 | // Pad year to at least 4 digits. |
| 464 | y := year |
| 465 | switch { |
| 466 | case year <= -1000: |
| 467 | b = append(b, '-') |
| 468 | y = -y |
| 469 | case year <= -100: |
| 470 | b = append(b, "-0"...) |
| 471 | y = -y |
| 472 | case year <= -10: |
| 473 | b = append(b, "-00"...) |
| 474 | y = -y |
| 475 | case year < 0: |
| 476 | b = append(b, "-000"...) |
| 477 | y = -y |
| 478 | case year < 10: |
| 479 | b = append(b, "000"...) |
| 480 | case year < 100: |
| 481 | b = append(b, "00"...) |
| 482 | case year < 1000: |
| 483 | b = append(b, '0') |
| 484 | } |
| 485 | b = appendUint(b, uint(y), 0) |
| 486 | case stdMonth: |
| 487 | b = append(b, month.String()[:3]...) |
| 488 | case stdLongMonth: |
| 489 | m := month.String() |
| 490 | b = append(b, m...) |
| 491 | case stdNumMonth: |
| 492 | b = appendUint(b, uint(month), 0) |
| 493 | case stdZeroMonth: |
| 494 | b = appendUint(b, uint(month), '0') |
| 495 | case stdWeekDay: |
| 496 | b = append(b, absWeekday(abs).String()[:3]...) |
| 497 | case stdLongWeekDay: |
| 498 | s := absWeekday(abs).String() |
| 499 | b = append(b, s...) |
| 500 | case stdDay: |
| 501 | b = appendUint(b, uint(day), 0) |
| 502 | case stdUnderDay: |
| 503 | b = appendUint(b, uint(day), ' ') |
| 504 | case stdZeroDay: |
| 505 | b = appendUint(b, uint(day), '0') |
| 506 | case stdHour: |
| 507 | b = appendUint(b, uint(hour), '0') |
| 508 | case stdHour12: |
| 509 | // Noon is 12PM, midnight is 12AM. |
| 510 | hr := hour % 12 |
| 511 | if hr == 0 { |
| 512 | hr = 12 |
| 513 | } |
| 514 | b = appendUint(b, uint(hr), 0) |
| 515 | case stdZeroHour12: |
| 516 | // Noon is 12PM, midnight is 12AM. |
| 517 | hr := hour % 12 |
| 518 | if hr == 0 { |
| 519 | hr = 12 |
| 520 | } |
| 521 | b = appendUint(b, uint(hr), '0') |
| 522 | case stdMinute: |
| 523 | b = appendUint(b, uint(min), 0) |
| 524 | case stdZeroMinute: |
| 525 | b = appendUint(b, uint(min), '0') |
| 526 | case stdSecond: |
| 527 | b = appendUint(b, uint(sec), 0) |
| 528 | case stdZeroSecond: |
| 529 | b = appendUint(b, uint(sec), '0') |
| 530 | case stdPM: |
| 531 | if hour >= 12 { |
| 532 | b = append(b, "PM"...) |
| 533 | } else { |
| 534 | b = append(b, "AM"...) |
| 535 | } |
| 536 | case stdpm: |
| 537 | if hour >= 12 { |
| 538 | b = append(b, "pm"...) |
| 539 | } else { |
| 540 | b = append(b, "am"...) |
| 541 | } |
| 542 | case stdISO8601TZ, stdISO8601ColonTZ, stdISO8601SecondsTZ, stdISO8601ColonSecondsTZ, stdNumTZ, stdNumColonTZ, stdNumSecondsTz, stdNumColonSecondsTZ: |
| 543 | // Ugly special case. We cheat and take the "Z" variants |
| 544 | // to mean "the time zone as formatted for ISO 8601". |
| 545 | if offset == 0 && (std == stdISO8601TZ || std == stdISO8601ColonTZ || std == stdISO8601SecondsTZ || std == stdISO8601ColonSecondsTZ) { |
| 546 | b = append(b, 'Z') |
| 547 | break |
| 548 | } |
| 549 | zone := offset / 60 // convert to minutes |
| 550 | absoffset := offset |
| 551 | if zone < 0 { |
| 552 | b = append(b, '-') |
| 553 | zone = -zone |
| 554 | absoffset = -absoffset |
| 555 | } else { |
| 556 | b = append(b, '+') |
| 557 | } |
| 558 | b = appendUint(b, uint(zone/60), '0') |
| 559 | if std == stdISO8601ColonTZ || std == stdNumColonTZ || std == stdISO8601ColonSecondsTZ || std == stdNumColonSecondsTZ { |
| 560 | b = append(b, ':') |
| 561 | } |
| 562 | b = appendUint(b, uint(zone%60), '0') |
| 563 | |
| 564 | // append seconds if appropriate |
| 565 | if std == stdISO8601SecondsTZ || std == stdNumSecondsTz || std == stdNumColonSecondsTZ || std == stdISO8601ColonSecondsTZ { |
| 566 | if std == stdNumColonSecondsTZ || std == stdISO8601ColonSecondsTZ { |
| 567 | b = append(b, ':') |
| 568 | } |
| 569 | b = appendUint(b, uint(absoffset%60), '0') |
| 570 | } |
| 571 | |
| 572 | case stdTZ: |
| 573 | if name != "" { |
| 574 | b = append(b, name...) |
| 575 | break |
| 576 | } |
| 577 | // No time zone known for this time, but we must print one. |
| 578 | // Use the -0700 format. |
| 579 | zone := offset / 60 // convert to minutes |
| 580 | if zone < 0 { |
| 581 | b = append(b, '-') |
| 582 | zone = -zone |
| 583 | } else { |
| 584 | b = append(b, '+') |
| 585 | } |
| 586 | b = appendUint(b, uint(zone/60), '0') |
| 587 | b = appendUint(b, uint(zone%60), '0') |
| 588 | case stdFracSecond0, stdFracSecond9: |
| 589 | b = formatNano(b, uint(t.Nanosecond()), std>>stdArgShift, std&stdMask == stdFracSecond9) |
| 590 | } |
| 591 | } |
| 592 | return string(b) |
| 593 | } |
| 594 | |
| 595 | var errBad = errors.New("bad value for field") // placeholder not passed to user |
| 596 | |
| 597 | // ParseError describes a problem parsing a time string. |
| 598 | type ParseError struct { |
| 599 | Layout string |
| 600 | Value string |
| 601 | LayoutElem string |
| 602 | ValueElem string |
| 603 | Message string |
| 604 | } |
| 605 | |
| 606 | func quote(s string) string { |
| 607 | return "\"" + s + "\"" |
| 608 | } |
| 609 | |
| 610 | // Error returns the string representation of a ParseError. |
| 611 | func (e *ParseError) Error() string { |
| 612 | if e.Message == "" { |
| 613 | return "parsing time " + |
| 614 | quote(e.Value) + " as " + |
| 615 | quote(e.Layout) + ": cannot parse " + |
| 616 | quote(e.ValueElem) + " as " + |
| 617 | quote(e.LayoutElem) |
| 618 | } |
| 619 | return "parsing time " + |
| 620 | quote(e.Value) + e.Message |
| 621 | } |
| 622 | |
| 623 | // isDigit returns true if s[i] is a decimal digit, false if not or |
| 624 | // if s[i] is out of range. |
| 625 | func isDigit(s string, i int) bool { |
| 626 | if len(s) <= i { |
| 627 | return false |
| 628 | } |
| 629 | c := s[i] |
| 630 | return '0' <= c && c <= '9' |
| 631 | } |
| 632 | |
| 633 | // getnum parses s[0:1] or s[0:2] (fixed forces the latter) |
| 634 | // as a decimal integer and returns the integer and the |
| 635 | // remainder of the string. |
| 636 | func getnum(s string, fixed bool) (int, string, error) { |
| 637 | if !isDigit(s, 0) { |
| 638 | return 0, s, errBad |
| 639 | } |
| 640 | if !isDigit(s, 1) { |
| 641 | if fixed { |
| 642 | return 0, s, errBad |
| 643 | } |
| 644 | return int(s[0] - '0'), s[1:], nil |
| 645 | } |
| 646 | return int(s[0]-'0')*10 + int(s[1]-'0'), s[2:], nil |
| 647 | } |
| 648 | |
| 649 | func cutspace(s string) string { |
| 650 | for len(s) > 0 && s[0] == ' ' { |
| 651 | s = s[1:] |
| 652 | } |
| 653 | return s |
| 654 | } |
| 655 | |
| 656 | // skip removes the given prefix from value, |
| 657 | // treating runs of space characters as equivalent. |
| 658 | func skip(value, prefix string) (string, error) { |
| 659 | for len(prefix) > 0 { |
| 660 | if prefix[0] == ' ' { |
| 661 | if len(value) > 0 && value[0] != ' ' { |
| 662 | return value, errBad |
| 663 | } |
| 664 | prefix = cutspace(prefix) |
| 665 | value = cutspace(value) |
| 666 | continue |
| 667 | } |
| 668 | if len(value) == 0 || value[0] != prefix[0] { |
| 669 | return value, errBad |
| 670 | } |
| 671 | prefix = prefix[1:] |
| 672 | value = value[1:] |
| 673 | } |
| 674 | return value, nil |
| 675 | } |
| 676 | |
| 677 | // Parse parses a formatted string and returns the time value it represents. |
| 678 | // The layout defines the format by showing how the reference time, |
| 679 | // defined to be |
| 680 | // Mon Jan 2 15:04:05 -0700 MST 2006 |
| 681 | // would be interpreted if it were the value; it serves as an example of |
| 682 | // the input format. The same interpretation will then be made to the |
| 683 | // input string. |
| 684 | // Predefined layouts ANSIC, UnixDate, RFC3339 and others describe standard |
| 685 | // and convenient representations of the reference time. For more information |
| 686 | // about the formats and the definition of the reference time, see the |
| 687 | // documentation for ANSIC and the other constants defined by this package. |
| 688 | // |
| 689 | // Elements omitted from the value are assumed to be zero or, when |
| 690 | // zero is impossible, one, so parsing "3:04pm" returns the time |
| 691 | // corresponding to Jan 1, year 0, 15:04:00 UTC (note that because the year is |
| 692 | // 0, this time is before the zero Time). |
| 693 | // Years must be in the range 0000..9999. The day of the week is checked |
| 694 | // for syntax but it is otherwise ignored. |
| 695 | // |
| 696 | // In the absence of a time zone indicator, Parse returns a time in UTC. |
| 697 | // |
| 698 | // When parsing a time with a zone offset like -0700, if the offset corresponds |
| 699 | // to a time zone used by the current location (Local), then Parse uses that |
| 700 | // location and zone in the returned time. Otherwise it records the time as |
| 701 | // being in a fabricated location with time fixed at the given zone offset. |
| 702 | // |
| 703 | // When parsing a time with a zone abbreviation like MST, if the zone abbreviation |
| 704 | // has a defined offset in the current location, then that offset is used. |
| 705 | // The zone abbreviation "UTC" is recognized as UTC regardless of location. |
| 706 | // If the zone abbreviation is unknown, Parse records the time as being |
| 707 | // in a fabricated location with the given zone abbreviation and a zero offset. |
| 708 | // This choice means that such a time can be parsed and reformatted with the |
| 709 | // same layout losslessly, but the exact instant used in the representation will |
| 710 | // differ by the actual zone offset. To avoid such problems, prefer time layouts |
| 711 | // that use a numeric zone offset, or use ParseInLocation. |
| 712 | func Parse(layout, value string) (Time, error) { |
| 713 | return parse(layout, value, UTC, Local) |
| 714 | } |
| 715 | |
| 716 | // ParseInLocation is like Parse but differs in two important ways. |
| 717 | // First, in the absence of time zone information, Parse interprets a time as UTC; |
| 718 | // ParseInLocation interprets the time as in the given location. |
| 719 | // Second, when given a zone offset or abbreviation, Parse tries to match it |
| 720 | // against the Local location; ParseInLocation uses the given location. |
| 721 | func ParseInLocation(layout, value string, loc *Location) (Time, error) { |
| 722 | return parse(layout, value, loc, loc) |
| 723 | } |
| 724 | |
| 725 | func parse(layout, value string, defaultLocation, local *Location) (Time, error) { |
| 726 | alayout, avalue := layout, value |
| 727 | rangeErrString := "" // set if a value is out of range |
| 728 | amSet := false // do we need to subtract 12 from the hour for midnight? |
| 729 | pmSet := false // do we need to add 12 to the hour? |
| 730 | |
| 731 | // Time being constructed. |
| 732 | var ( |
| 733 | year int |
| 734 | month int = 1 // January |
| 735 | day int = 1 |
| 736 | hour int |
| 737 | min int |
| 738 | sec int |
| 739 | nsec int |
| 740 | z *Location |
| 741 | zoneOffset int = -1 |
| 742 | zoneName string |
| 743 | ) |
| 744 | |
| 745 | // Each iteration processes one std value. |
| 746 | for { |
| 747 | var err error |
| 748 | prefix, std, suffix := nextStdChunk(layout) |
| 749 | stdstr := layout[len(prefix) : len(layout)-len(suffix)] |
| 750 | value, err = skip(value, prefix) |
| 751 | if err != nil { |
| 752 | return Time{}, &ParseError{alayout, avalue, prefix, value, ""} |
| 753 | } |
| 754 | if std == 0 { |
| 755 | if len(value) != 0 { |
| 756 | return Time{}, &ParseError{alayout, avalue, "", value, ": extra text: " + value} |
| 757 | } |
| 758 | break |
| 759 | } |
| 760 | layout = suffix |
| 761 | var p string |
| 762 | switch std & stdMask { |
| 763 | case stdYear: |
| 764 | if len(value) < 2 { |
| 765 | err = errBad |
| 766 | break |
| 767 | } |
| 768 | p, value = value[0:2], value[2:] |
| 769 | year, err = atoi(p) |
| 770 | if year >= 69 { // Unix time starts Dec 31 1969 in some time zones |
| 771 | year += 1900 |
| 772 | } else { |
| 773 | year += 2000 |
| 774 | } |
| 775 | case stdLongYear: |
| 776 | if len(value) < 4 || !isDigit(value, 0) { |
| 777 | err = errBad |
| 778 | break |
| 779 | } |
| 780 | p, value = value[0:4], value[4:] |
| 781 | year, err = atoi(p) |
| 782 | case stdMonth: |
| 783 | month, value, err = lookup(shortMonthNames, value) |
| 784 | case stdLongMonth: |
| 785 | month, value, err = lookup(longMonthNames, value) |
| 786 | case stdNumMonth, stdZeroMonth: |
| 787 | month, value, err = getnum(value, std == stdZeroMonth) |
| 788 | if month <= 0 || 12 < month { |
| 789 | rangeErrString = "month" |
| 790 | } |
| 791 | case stdWeekDay: |
| 792 | // Ignore weekday except for error checking. |
| 793 | _, value, err = lookup(shortDayNames, value) |
| 794 | case stdLongWeekDay: |
| 795 | _, value, err = lookup(longDayNames, value) |
| 796 | case stdDay, stdUnderDay, stdZeroDay: |
| 797 | if std == stdUnderDay && len(value) > 0 && value[0] == ' ' { |
| 798 | value = value[1:] |
| 799 | } |
| 800 | day, value, err = getnum(value, std == stdZeroDay) |
| 801 | if day < 0 || 31 < day { |
| 802 | rangeErrString = "day" |
| 803 | } |
| 804 | case stdHour: |
| 805 | hour, value, err = getnum(value, false) |
| 806 | if hour < 0 || 24 <= hour { |
| 807 | rangeErrString = "hour" |
| 808 | } |
| 809 | case stdHour12, stdZeroHour12: |
| 810 | hour, value, err = getnum(value, std == stdZeroHour12) |
| 811 | if hour < 0 || 12 < hour { |
| 812 | rangeErrString = "hour" |
| 813 | } |
| 814 | case stdMinute, stdZeroMinute: |
| 815 | min, value, err = getnum(value, std == stdZeroMinute) |
| 816 | if min < 0 || 60 <= min { |
| 817 | rangeErrString = "minute" |
| 818 | } |
| 819 | case stdSecond, stdZeroSecond: |
| 820 | sec, value, err = getnum(value, std == stdZeroSecond) |
| 821 | if sec < 0 || 60 <= sec { |
| 822 | rangeErrString = "second" |
| 823 | } |
| 824 | // Special case: do we have a fractional second but no |
| 825 | // fractional second in the format? |
| 826 | if len(value) >= 2 && value[0] == '.' && isDigit(value, 1) { |
| 827 | _, std, _ = nextStdChunk(layout) |
| 828 | std &= stdMask |
| 829 | if std == stdFracSecond0 || std == stdFracSecond9 { |
| 830 | // Fractional second in the layout; proceed normally |
| 831 | break |
| 832 | } |
| 833 | // No fractional second in the layout but we have one in the input. |
| 834 | n := 2 |
| 835 | for ; n < len(value) && isDigit(value, n); n++ { |
| 836 | } |
| 837 | nsec, rangeErrString, err = parseNanoseconds(value, n) |
| 838 | value = value[n:] |
| 839 | } |
| 840 | case stdPM: |
| 841 | if len(value) < 2 { |
| 842 | err = errBad |
| 843 | break |
| 844 | } |
| 845 | p, value = value[0:2], value[2:] |
| 846 | switch p { |
| 847 | case "PM": |
| 848 | pmSet = true |
| 849 | case "AM": |
| 850 | amSet = true |
| 851 | default: |
| 852 | err = errBad |
| 853 | } |
| 854 | case stdpm: |
| 855 | if len(value) < 2 { |
| 856 | err = errBad |
| 857 | break |
| 858 | } |
| 859 | p, value = value[0:2], value[2:] |
| 860 | switch p { |
| 861 | case "pm": |
| 862 | pmSet = true |
| 863 | case "am": |
| 864 | amSet = true |
| 865 | default: |
| 866 | err = errBad |
| 867 | } |
| 868 | case stdISO8601TZ, stdISO8601ColonTZ, stdISO8601SecondsTZ, stdISO8601ColonSecondsTZ, stdNumTZ, stdNumShortTZ, stdNumColonTZ, stdNumSecondsTz, stdNumColonSecondsTZ: |
| 869 | if (std == stdISO8601TZ || std == stdISO8601ColonTZ) && len(value) >= 1 && value[0] == 'Z' { |
| 870 | value = value[1:] |
| 871 | z = UTC |
| 872 | break |
| 873 | } |
| 874 | var sign, hour, min, seconds string |
| 875 | if std == stdISO8601ColonTZ || std == stdNumColonTZ { |
| 876 | if len(value) < 6 { |
| 877 | err = errBad |
| 878 | break |
| 879 | } |
| 880 | if value[3] != ':' { |
| 881 | err = errBad |
| 882 | break |
| 883 | } |
| 884 | sign, hour, min, seconds, value = value[0:1], value[1:3], value[4:6], "00", value[6:] |
| 885 | } else if std == stdNumShortTZ { |
| 886 | if len(value) < 3 { |
| 887 | err = errBad |
| 888 | break |
| 889 | } |
| 890 | sign, hour, min, seconds, value = value[0:1], value[1:3], "00", "00", value[3:] |
| 891 | } else if std == stdISO8601ColonSecondsTZ || std == stdNumColonSecondsTZ { |
| 892 | if len(value) < 9 { |
| 893 | err = errBad |
| 894 | break |
| 895 | } |
| 896 | if value[3] != ':' || value[6] != ':' { |
| 897 | err = errBad |
| 898 | break |
| 899 | } |
| 900 | sign, hour, min, seconds, value = value[0:1], value[1:3], value[4:6], value[7:9], value[9:] |
| 901 | } else if std == stdISO8601SecondsTZ || std == stdNumSecondsTz { |
| 902 | if len(value) < 7 { |
| 903 | err = errBad |
| 904 | break |
| 905 | } |
| 906 | sign, hour, min, seconds, value = value[0:1], value[1:3], value[3:5], value[5:7], value[7:] |
| 907 | } else { |
| 908 | if len(value) < 5 { |
| 909 | err = errBad |
| 910 | break |
| 911 | } |
| 912 | sign, hour, min, seconds, value = value[0:1], value[1:3], value[3:5], "00", value[5:] |
| 913 | } |
| 914 | var hr, mm, ss int |
| 915 | hr, err = atoi(hour) |
| 916 | if err == nil { |
| 917 | mm, err = atoi(min) |
| 918 | } |
| 919 | if err == nil { |
| 920 | ss, err = atoi(seconds) |
| 921 | } |
| 922 | zoneOffset = (hr*60+mm)*60 + ss // offset is in seconds |
| 923 | switch sign[0] { |
| 924 | case '+': |
| 925 | case '-': |
| 926 | zoneOffset = -zoneOffset |
| 927 | default: |
| 928 | err = errBad |
| 929 | } |
| 930 | case stdTZ: |
| 931 | // Does it look like a time zone? |
| 932 | if len(value) >= 3 && value[0:3] == "UTC" { |
| 933 | z = UTC |
| 934 | value = value[3:] |
| 935 | break |
| 936 | } |
| 937 | n, ok := parseTimeZone(value) |
| 938 | if !ok { |
| 939 | err = errBad |
| 940 | break |
| 941 | } |
| 942 | zoneName, value = value[:n], value[n:] |
| 943 | |
| 944 | case stdFracSecond0: |
| 945 | // stdFracSecond0 requires the exact number of digits as specified in |
| 946 | // the layout. |
| 947 | ndigit := 1 + (std >> stdArgShift) |
| 948 | if len(value) < ndigit { |
| 949 | err = errBad |
| 950 | break |
| 951 | } |
| 952 | nsec, rangeErrString, err = parseNanoseconds(value, ndigit) |
| 953 | value = value[ndigit:] |
| 954 | |
| 955 | case stdFracSecond9: |
| 956 | if len(value) < 2 || value[0] != '.' || value[1] < '0' || '9' < value[1] { |
| 957 | // Fractional second omitted. |
| 958 | break |
| 959 | } |
| 960 | // Take any number of digits, even more than asked for, |
| 961 | // because it is what the stdSecond case would do. |
| 962 | i := 0 |
| 963 | for i < 9 && i+1 < len(value) && '0' <= value[i+1] && value[i+1] <= '9' { |
| 964 | i++ |
| 965 | } |
| 966 | nsec, rangeErrString, err = parseNanoseconds(value, 1+i) |
| 967 | value = value[1+i:] |
| 968 | } |
| 969 | if rangeErrString != "" { |
| 970 | return Time{}, &ParseError{alayout, avalue, stdstr, value, ": " + rangeErrString + " out of range"} |
| 971 | } |
| 972 | if err != nil { |
| 973 | return Time{}, &ParseError{alayout, avalue, stdstr, value, ""} |
| 974 | } |
| 975 | } |
| 976 | if pmSet && hour < 12 { |
| 977 | hour += 12 |
| 978 | } else if amSet && hour == 12 { |
| 979 | hour = 0 |
| 980 | } |
| 981 | |
| 982 | if z != nil { |
| 983 | return Date(year, Month(month), day, hour, min, sec, nsec, z), nil |
| 984 | } |
| 985 | |
| 986 | if zoneOffset != -1 { |
| 987 | t := Date(year, Month(month), day, hour, min, sec, nsec, UTC) |
| 988 | t.sec -= int64(zoneOffset) |
| 989 | |
| 990 | // Look for local zone with the given offset. |
| 991 | // If that zone was in effect at the given time, use it. |
| 992 | name, offset, _, _, _ := local.lookup(t.sec + internalToUnix) |
| 993 | if offset == zoneOffset && (zoneName == "" || name == zoneName) { |
| 994 | t.loc = local |
| 995 | return t, nil |
| 996 | } |
| 997 | |
| 998 | // Otherwise create fake zone to record offset. |
| 999 | t.loc = FixedZone(zoneName, zoneOffset) |
| 1000 | return t, nil |
| 1001 | } |
| 1002 | |
| 1003 | if zoneName != "" { |
| 1004 | t := Date(year, Month(month), day, hour, min, sec, nsec, UTC) |
| 1005 | // Look for local zone with the given offset. |
| 1006 | // If that zone was in effect at the given time, use it. |
| 1007 | offset, _, ok := local.lookupName(zoneName, t.sec+internalToUnix) |
| 1008 | if ok { |
| 1009 | t.sec -= int64(offset) |
| 1010 | t.loc = local |
| 1011 | return t, nil |
| 1012 | } |
| 1013 | |
| 1014 | // Otherwise, create fake zone with unknown offset. |
| 1015 | if len(zoneName) > 3 && zoneName[:3] == "GMT" { |
| 1016 | offset, _ = atoi(zoneName[3:]) // Guaranteed OK by parseGMT. |
| 1017 | offset *= 3600 |
| 1018 | } |
| 1019 | t.loc = FixedZone(zoneName, offset) |
| 1020 | return t, nil |
| 1021 | } |
| 1022 | |
| 1023 | // Otherwise, fall back to default. |
| 1024 | return Date(year, Month(month), day, hour, min, sec, nsec, defaultLocation), nil |
| 1025 | } |
| 1026 | |
| 1027 | // parseTimeZone parses a time zone string and returns its length. Time zones |
| 1028 | // are human-generated and unpredictable. We can't do precise error checking. |
| 1029 | // On the other hand, for a correct parse there must be a time zone at the |
| 1030 | // beginning of the string, so it's almost always true that there's one |
| 1031 | // there. We look at the beginning of the string for a run of upper-case letters. |
| 1032 | // If there are more than 5, it's an error. |
| 1033 | // If there are 4 or 5 and the last is a T, it's a time zone. |
| 1034 | // If there are 3, it's a time zone. |
| 1035 | // Otherwise, other than special cases, it's not a time zone. |
| 1036 | // GMT is special because it can have an hour offset. |
| 1037 | func parseTimeZone(value string) (length int, ok bool) { |
| 1038 | if len(value) < 3 { |
| 1039 | return 0, false |
| 1040 | } |
| 1041 | // Special case 1: ChST and MeST are the only zones with a lower-case letter. |
| 1042 | if len(value) >= 4 && (value[:4] == "ChST" || value[:4] == "MeST") { |
| 1043 | return 4, true |
| 1044 | } |
| 1045 | // Special case 2: GMT may have an hour offset; treat it specially. |
| 1046 | if value[:3] == "GMT" { |
| 1047 | length = parseGMT(value) |
| 1048 | return length, true |
| 1049 | } |
| 1050 | // How many upper-case letters are there? Need at least three, at most five. |
| 1051 | var nUpper int |
| 1052 | for nUpper = 0; nUpper < 6; nUpper++ { |
| 1053 | if nUpper >= len(value) { |
| 1054 | break |
| 1055 | } |
| 1056 | if c := value[nUpper]; c < 'A' || 'Z' < c { |
| 1057 | break |
| 1058 | } |
| 1059 | } |
| 1060 | switch nUpper { |
| 1061 | case 0, 1, 2, 6: |
| 1062 | return 0, false |
| 1063 | case 5: // Must end in T to match. |
| 1064 | if value[4] == 'T' { |
| 1065 | return 5, true |
| 1066 | } |
| 1067 | case 4: // Must end in T to match. |
| 1068 | if value[3] == 'T' { |
| 1069 | return 4, true |
| 1070 | } |
| 1071 | case 3: |
| 1072 | return 3, true |
| 1073 | } |
| 1074 | return 0, false |
| 1075 | } |
| 1076 | |
| 1077 | // parseGMT parses a GMT time zone. The input string is known to start "GMT". |
| 1078 | // The function checks whether that is followed by a sign and a number in the |
| 1079 | // range -14 through 12 excluding zero. |
| 1080 | func parseGMT(value string) int { |
| 1081 | value = value[3:] |
| 1082 | if len(value) == 0 { |
| 1083 | return 3 |
| 1084 | } |
| 1085 | sign := value[0] |
| 1086 | if sign != '-' && sign != '+' { |
| 1087 | return 3 |
| 1088 | } |
| 1089 | x, rem, err := leadingInt(value[1:]) |
| 1090 | if err != nil { |
| 1091 | return 3 |
| 1092 | } |
| 1093 | if sign == '-' { |
| 1094 | x = -x |
| 1095 | } |
| 1096 | if x == 0 || x < -14 || 12 < x { |
| 1097 | return 3 |
| 1098 | } |
| 1099 | return 3 + len(value) - len(rem) |
| 1100 | } |
| 1101 | |
| 1102 | func parseNanoseconds(value string, nbytes int) (ns int, rangeErrString string, err error) { |
| 1103 | if value[0] != '.' { |
| 1104 | err = errBad |
| 1105 | return |
| 1106 | } |
| 1107 | if ns, err = atoi(value[1:nbytes]); err != nil { |
| 1108 | return |
| 1109 | } |
| 1110 | if ns < 0 || 1e9 <= ns { |
| 1111 | rangeErrString = "fractional second" |
| 1112 | return |
| 1113 | } |
| 1114 | // We need nanoseconds, which means scaling by the number |
| 1115 | // of missing digits in the format, maximum length 10. If it's |
| 1116 | // longer than 10, we won't scale. |
| 1117 | scaleDigits := 10 - nbytes |
| 1118 | for i := 0; i < scaleDigits; i++ { |
| 1119 | ns *= 10 |
| 1120 | } |
| 1121 | return |
| 1122 | } |
| 1123 | |
| 1124 | var errLeadingInt = errors.New("time: bad [0-9]*") // never printed |
| 1125 | |
| 1126 | // leadingInt consumes the leading [0-9]* from s. |
| 1127 | func leadingInt(s string) (x int64, rem string, err error) { |
| 1128 | i := 0 |
| 1129 | for ; i < len(s); i++ { |
| 1130 | c := s[i] |
| 1131 | if c < '0' || c > '9' { |
| 1132 | break |
| 1133 | } |
| 1134 | if x >= (1<<63-10)/10 { |
| 1135 | // overflow |
| 1136 | return 0, "", errLeadingInt |
| 1137 | } |
| 1138 | x = x*10 + int64(c) - '0' |
| 1139 | } |
| 1140 | return x, s[i:], nil |
| 1141 | } |
| 1142 | |
| 1143 | var unitMap = map[string]float64{ |
| 1144 | "ns": float64(Nanosecond), |
| 1145 | "us": float64(Microsecond), |
| 1146 | "µs": float64(Microsecond), // U+00B5 = micro symbol |
| 1147 | "μs": float64(Microsecond), // U+03BC = Greek letter mu |
| 1148 | "ms": float64(Millisecond), |
| 1149 | "s": float64(Second), |
| 1150 | "m": float64(Minute), |
| 1151 | "h": float64(Hour), |
| 1152 | } |
| 1153 | |
| 1154 | // ParseDuration parses a duration string. |
| 1155 | // A duration string is a possibly signed sequence of |
| 1156 | // decimal numbers, each with optional fraction and a unit suffix, |
| 1157 | // such as "300ms", "-1.5h" or "2h45m". |
| 1158 | // Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h". |
| 1159 | func ParseDuration(s string) (Duration, error) { |
| 1160 | // [-+]?([0-9]*(\.[0-9]*)?[a-z]+)+ |
| 1161 | orig := s |
| 1162 | f := float64(0) |
| 1163 | neg := false |
| 1164 | |
| 1165 | // Consume [-+]? |
| 1166 | if s != "" { |
| 1167 | c := s[0] |
| 1168 | if c == '-' || c == '+' { |
| 1169 | neg = c == '-' |
| 1170 | s = s[1:] |
| 1171 | } |
| 1172 | } |
| 1173 | // Special case: if all that is left is "0", this is zero. |
| 1174 | if s == "0" { |
| 1175 | return 0, nil |
| 1176 | } |
| 1177 | if s == "" { |
| 1178 | return 0, errors.New("time: invalid duration " + orig) |
| 1179 | } |
| 1180 | for s != "" { |
| 1181 | g := float64(0) // this element of the sequence |
| 1182 | |
| 1183 | var x int64 |
| 1184 | var err error |
| 1185 | |
| 1186 | // The next character must be [0-9.] |
| 1187 | if !(s[0] == '.' || ('0' <= s[0] && s[0] <= '9')) { |
| 1188 | return 0, errors.New("time: invalid duration " + orig) |
| 1189 | } |
| 1190 | // Consume [0-9]* |
| 1191 | pl := len(s) |
| 1192 | x, s, err = leadingInt(s) |
| 1193 | if err != nil { |
| 1194 | return 0, errors.New("time: invalid duration " + orig) |
| 1195 | } |
| 1196 | g = float64(x) |
| 1197 | pre := pl != len(s) // whether we consumed anything before a period |
| 1198 | |
| 1199 | // Consume (\.[0-9]*)? |
| 1200 | post := false |
| 1201 | if s != "" && s[0] == '.' { |
| 1202 | s = s[1:] |
| 1203 | pl := len(s) |
| 1204 | x, s, err = leadingInt(s) |
| 1205 | if err != nil { |
| 1206 | return 0, errors.New("time: invalid duration " + orig) |
| 1207 | } |
| 1208 | scale := 1.0 |
| 1209 | for n := pl - len(s); n > 0; n-- { |
| 1210 | scale *= 10 |
| 1211 | } |
| 1212 | g += float64(x) / scale |
| 1213 | post = pl != len(s) |
| 1214 | } |
| 1215 | if !pre && !post { |
| 1216 | // no digits (e.g. ".s" or "-.s") |
| 1217 | return 0, errors.New("time: invalid duration " + orig) |
| 1218 | } |
| 1219 | |
| 1220 | // Consume unit. |
| 1221 | i := 0 |
| 1222 | for ; i < len(s); i++ { |
| 1223 | c := s[i] |
| 1224 | if c == '.' || ('0' <= c && c <= '9') { |
| 1225 | break |
| 1226 | } |
| 1227 | } |
| 1228 | if i == 0 { |
| 1229 | return 0, errors.New("time: missing unit in duration " + orig) |
| 1230 | } |
| 1231 | u := s[:i] |
| 1232 | s = s[i:] |
| 1233 | unit, ok := unitMap[u] |
| 1234 | if !ok { |
| 1235 | return 0, errors.New("time: unknown unit " + u + " in duration " + orig) |
| 1236 | } |
| 1237 | |
| 1238 | f += g * unit |
| 1239 | } |
| 1240 | |
| 1241 | if neg { |
| 1242 | f = -f |
| 1243 | } |
| 1244 | if f < float64(-1<<63) || f > float64(1<<63-1) { |
| 1245 | return 0, errors.New("time: overflow parsing duration") |
| 1246 | } |
| 1247 | return Duration(f), nil |
| 1248 | } |