8 type canInfinite interface {
13 // A range of episodes with a start and possibly without an end.
14 type EpisodeRange struct {
15 Type EpisodeType // Must be equal to both the Start and End types; if End is nil, must be equal to the Start type
16 Start *Episode // The start of the range
17 End *Episode // The end of the range; may be nil, which represents an endless range
20 func EpisodeToRange(ep *Episode) *EpisodeRange {
28 // Converts the EpisodeRange into AniDB API range format.
29 func (er *EpisodeRange) String() string {
30 return er.Format(er.scale())
33 func (er *EpisodeRange) Format(width int) string {
34 if er.Start == er.End || (er.End != nil && *(er.Start) == *(er.End)) {
35 return er.Start.Format(width)
39 return fmt.Sprintf("%s-", er.Start.Format(width))
41 return fmt.Sprintf("%s-%s", er.Start.Format(width), er.End.Format(width))
44 func (er *EpisodeRange) FormatLog(max int) string {
45 return er.Format(scale(max))
48 func (er *EpisodeRange) scale() int {
52 s, e := er.Start.scale(), er.End.scale()
59 func (er *EpisodeRange) Infinite() bool {
60 return er != nil && er.End == nil
63 // Returns a channel that can be used to iterate using for/range.
65 // If the EpisodeRange is infinite, then the channel is also infinite.
66 // The caller is allowed to close the channel in such case.
67 func (er *EpisodeRange) Episodes() chan Episode {
68 ch := make(chan Episode, 1)
69 if er == nil || er.Start == nil {
85 // we allow the caller to close the channel on infinite lists
86 defer func() { recover(); abort = true }()
95 for ; !abort && ep.Parts > 0 && ep.Number == start.Number; ep.IncPart() {
98 for ; !abort; ep.IncNumber() {
101 case start.Part == -1 && end.Part == -1:
102 for ; ep.Number <= end.Number; ep.IncNumber() {
105 case start.Parts > 0:
106 for ; ep.Number == start.Number; ep.IncPart() {
111 for ; ep.Number < end.Number; ep.IncNumber() {
117 for ; ep.Part <= end.Part; ep.IncPart() {
125 // If ec is an *Episode, returns true if the Episode is of the same type as the range
126 // and has a Number >= Start.Number; if End is defined, then the episode's Number must
127 // also be <= End.Number.
129 // If ec is an *EpisodeRange, returns true if they are both of the same type and
130 // the ec's Start.Number is >= this range's Start.Number;
131 // also returns true if this EpisodeRange is unbounded or if the ec is bounded
132 // and ec's End.Number is <= this range's End.Number.
134 // If ec is an EpisodeList, returns true if all listed EpisodeRanges are contained
135 // by this EpisodeRange.
137 // Returns false otherwise.
138 func (er *EpisodeRange) ContainsEpisodes(ec EpisodeContainer) bool {
142 if er.Start == nil || er.Start.Type != er.Type ||
143 (er.End != nil && er.End.Type != er.Type) {
144 panic("Invalid EpisodeRange used")
147 switch e := ec.(type) {
149 if e.Type == er.Type && e.Number >= er.Start.Number {
152 } else if e.Number <= er.End.Number {
157 if e.Type == er.Type {
158 if e.Start.Number >= er.Start.Number {
161 } else if e.End == nil {
162 return false // a finite set can't contain an infinite one
163 } else if e.End.Number <= er.End.Number {
169 for _, ec := range e {
170 if !er.ContainsEpisodes(ec) {
180 // Tries to merge a with b, returning a new *EpisodeRange that's
181 // a superset of both a and b.
183 // Returns nil if a and b don't intersect, or are not adjacent.
184 func (a *EpisodeRange) Merge(b *EpisodeRange) (c *EpisodeRange) {
186 c = &EpisodeRange{Type: a.Type}
189 case a.Start.Number == b.Start.Number:
191 case a.Start.Part < 0:
193 case b.Start.Part < 0:
195 case a.Start.Part <= b.Start.Part:
200 case a.Start.Number < b.Start.Number:
207 case a.End == nil || b.End == nil:
209 case a.End.Number == b.End.Number:
215 case a.End.Part >= b.End.Part:
220 case a.End.Number > b.End.Number:
229 // Check if the given range is not nil, has a defined start
230 // and, if it has an end, that the end ends after the start.
231 func (er *EpisodeRange) Valid() bool {
233 case er == nil, er.Start == nil:
237 case er.Start.Number < er.End.Number:
239 case er.Start.Number > er.End.Number:
241 case er.Start.Part <= er.End.Part:
248 // Simplifies the Start/End ranges if one contains the other.
249 // Sets the pointers to be identical if the range is modified.
251 // Modifies in-place, returns itself.
252 func (er *EpisodeRange) Simplify() *EpisodeRange {
254 case er.Start.ContainsEpisodes(er.End):
256 case er.End != nil && er.End.ContainsEpisodes(er.Start):
262 // Splits the range into one or two ranges, using the given
263 // Episode as the split point. The Episode is not included in
264 // the resulting ranges.
265 func (er *EpisodeRange) Split(ep *Episode) []*EpisodeRange {
266 if !er.ContainsEpisodes(ep) { // implies same type
267 return []*EpisodeRange{er}
270 return []*EpisodeRange{nil, nil}
287 case a.ContainsEpisodes(ep) && b.ContainsEpisodes(ep):
288 return []*EpisodeRange{nil, nil}
289 case a.ContainsEpisodes(ep):
295 if a.Number == b.Number && b.Parts > 0 {
304 return []*EpisodeRange{nil, r.Simplify()}
305 case b.ContainsEpisodes(ep):
311 if b.Number == a.Number {
315 } else if b.Part < 0 {
324 return []*EpisodeRange{r.Simplify(), nil}
351 return []*EpisodeRange{ra, rb}
355 // Returns true if both ranges are of the same type and
356 // have identical start/end positions
357 func (a *EpisodeRange) Equals(b *EpisodeRange) bool {
358 if a == b { // pointers to the same thing
361 if a == nil || b == nil {
365 if a.Type == b.Type {
366 if a.End == b.End || (a.End != nil && b.End != nil &&
367 a.End.Number == b.End.Number && a.End.Part == b.End.Part) {
368 if a.Start == b.Start || a.Start.Number == b.Start.Number && a.Start.Part == b.Start.Part {
376 // CORNER CASE: e.g. 1.3,2.0 (or 1.3,2) never touch,
377 // unless it's known that 1.3 is the last part.
378 func (a *EpisodeRange) touches(b *EpisodeRange) bool {
379 if a == nil || b == nil || a.Type != b.Type {
385 // log.Println("same pointers")
387 case a.Start == b.Start, a.End != nil && a.End == b.End:
388 // log.Println("share pointers")
394 // log.Println("both infinite")
397 case b.End.Number == a.Start.Number:
399 // either is whole, or parts are adjacent/overlap
400 case b.End.Part == -1, a.Start.Part == -1,
401 b.End.Part >= a.Start.Part-1:
402 // log.Printf("{ %s [} %s ...", b.End, a.Start)
405 // only if start of next range is whole or is first part
406 case b.End.Number == a.Start.Number-1 && a.Start.Part <= 0:
408 // end is whole, or is last part, or part count is unknown
409 case b.End.Part == -1, b.End.Parts == 0,
410 b.End.Part == b.End.Parts:
411 // log.Printf("{ %s }[ %s ...", b.End, a.Start)
414 case b.End.Number > a.Start.Number:
415 // log.Printf("{ %s [ } %s ...", b.End, a.Start)
421 case a.End.Number == b.Start.Number:
423 case a.End.Part == -1, b.Start.Part == -1,
424 a.End.Part >= b.Start.Part-1:
425 // log.Printf("[ %s {] %s ...", a.End, b.Start)
428 case a.End.Number == b.Start.Number-1 && b.Start.Part <= 0:
430 case a.End.Part == -1, a.End.Parts == 0,
431 a.End.Part == a.End.Parts:
432 // log.Printf("[ %s ]{ %s ...", a.End, b.Start)
435 case a.End.Number > b.Start.Number:
436 // log.Printf("[ %s { ] %s ...", a.End, b.Start)
440 case a.Start.Number == b.Start.Number:
443 // either is whole, or parts are immediately adjacent
444 case a.Start.Part == -1, b.Start.Part == -1,
445 a.Start.Part == b.Start.Part,
446 a.Start.Part == b.Start.Part-1,
447 a.Start.Part == b.Start.Part+1:
448 // log.Printf("[{ %s - %s ]}", a.End, b.Start)
451 case a.End.Number == b.End.Number:
453 case a.End.Part == -1, b.End.Part == -1,
454 a.End.Part == b.End.Part,
455 a.End.Part == b.End.Part-1,
456 a.End.Part == b.End.Part+1:
457 // log.Printf("{[ %s - %s }]", b.End, a.Start)
461 case a.End.Number < b.End.Number:
463 case a.End.Number == b.Start.Number:
465 case a.End.Part == -1, b.Start.Part == -1,
466 a.End.Part >= b.Start.Part-1:
467 // log.Printf("[ %s {] %s }", a.End, b.Start)
470 case a.End.Number == b.Start.Number-1 && b.Start.Part <= 0:
472 case a.End.Part == -1, a.End.Part == a.End.Parts-1,
473 a.End.Part == b.Start.Parts:
474 // log.Printf("[ %s ]{ %s }", a.End, b.Start)
477 case a.End.Number > b.Start.Number:
478 // log.Printf("[ %s { ] %s }", a.End, b.Start)
482 case b.End.Number < a.End.Number:
484 case b.End.Number == a.Start.Number:
486 case b.End.Part == -1, a.Start.Part == -1,
487 b.End.Part >= a.Start.Part-1:
488 // log.Printf("{ %s [} %s ]", b.End, a.Start)
491 case b.End.Number == a.Start.Number-1 && a.Start.Part <= 0:
493 case b.End.Part == -1, b.End.Part == b.End.Parts-1,
494 b.End.Part == b.End.Parts:
495 // log.Printf("{ %s }[ %s ]", b.End, a.Start)
498 case b.End.Number > a.Start.Number:
499 // log.Printf("{ %s [ } %s ]", b.End, a.Start)
506 // Parses a string in the AniDB API range format and converts into an EpisodeRange.
507 func ParseEpisodeRange(s string) *EpisodeRange {
508 parts := strings.Split(s, "-")
514 for i := range parts {
515 eps[i] = ParseEpisode(parts[i])
521 // Not an interval (just "epno") --
522 // convert into interval starting and ending in the same episode
527 if len(parts) > 1 && eps[1] != nil && eps[0].Type != eps[1].Type {
530 return &EpisodeRange{