1// Copyright (c) 2017 Ernest Micklei 2// 3// MIT License 4// 5// Permission is hereby granted, free of charge, to any person obtaining 6// a copy of this software and associated documentation files (the 7// "Software"), to deal in the Software without restriction, including 8// without limitation the rights to use, copy, modify, merge, publish, 9// distribute, sublicense, and/or sell copies of the Software, and to 10// permit persons to whom the Software is furnished to do so, subject to 11// the following conditions: 12// 13// The above copyright notice and this permission notice shall be 14// included in all copies or substantial portions of the Software. 15// 16// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 20// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 21// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 22// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 24package proto 25 26import ( 27 "fmt" 28 "strconv" 29) 30 31// Range is to specify number intervals (with special end value "max") 32type Range struct { 33 From, To int 34 Max bool 35} 36 37// String return a single number if from = to. Returns <from> to <to> otherwise unless Max then return <from> to max. 38func (r Range) String() string { 39 if r.Max { 40 return fmt.Sprintf("%d to max", r.From) 41 } 42 if r.From == r.To { 43 return strconv.Itoa(r.From) 44 } 45 return fmt.Sprintf("%d to %d", r.From, r.To) 46} 47 48// parseRanges is used to parse ranges for extensions and reserved 49func parseRanges(p *Parser, n Visitee) (list []Range, err error) { 50 seenTo := false 51 for { 52 pos, tok, lit := p.next() 53 if isString(lit) { 54 return list, p.unexpected(lit, "integer, <to> <max>", n) 55 } 56 switch lit { 57 case ",": 58 case "to": 59 seenTo = true 60 case ";": 61 p.nextPut(pos, tok, lit) // allow for inline comment parsing 62 goto done 63 case "max": 64 if !seenTo { 65 return list, p.unexpected(lit, "to", n) 66 } 67 from := list[len(list)-1] 68 list = append(list[0:len(list)-1], Range{From: from.From, Max: true}) 69 default: 70 // must be number 71 i, err := strconv.Atoi(lit) 72 if err != nil { 73 return list, p.unexpected(lit, "range integer", n) 74 } 75 if seenTo { 76 // replace last two ranges with one 77 if len(list) < 1 { 78 p.unexpected(lit, "integer", n) 79 } 80 from := list[len(list)-1] 81 list = append(list[0:len(list)-1], Range{From: from.From, To: i}) 82 seenTo = false 83 } else { 84 list = append(list, Range{From: i, To: i}) 85 } 86 } 87 } 88done: 89 return 90} 91