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 24 package proto 25 26 import ( 27 "fmt" 28 "strconv" 29 ) 30 31 // Range is to specify number intervals (with special end value "max") 32 type Range struct { 33 From, To int 34 Max bool 35 } 36 37 // SourceRepresentation return a single number if from = to. Returns <from> to <to> otherwise unless Max then return <from> to max. 38 func (r Range) SourceRepresentation() 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 49 func parseRanges(p *Parser, n Visitee) (list []Range, err error) { 50 seenTo := false 51 negate := false // for numbers 52 for { 53 pos, tok, lit := p.next() 54 if isString(lit) { 55 return list, p.unexpected(lit, "integer, <to> <max>", n) 56 } 57 switch lit { 58 case "-": 59 negate = true 60 case ",": 61 case "to": 62 seenTo = true 63 case ";": 64 p.nextPut(pos, tok, lit) // allow for inline comment parsing 65 goto done 66 case "max": 67 if !seenTo { 68 return list, p.unexpected(lit, "to", n) 69 } 70 from := list[len(list)-1] 71 list = append(list[0:len(list)-1], Range{From: from.From, Max: true}) 72 default: 73 // must be number 74 i, err := strconv.Atoi(lit) 75 if err != nil { 76 return list, p.unexpected(lit, "range integer", n) 77 } 78 if negate { 79 i = -i 80 negate = false 81 } 82 if seenTo { 83 // replace last two ranges with one 84 if len(list) < 1 { 85 p.unexpected(lit, "integer", n) 86 } 87 from := list[len(list)-1] 88 list = append(list[0:len(list)-1], Range{From: from.From, To: i}) 89 seenTo = false 90 } else { 91 list = append(list, Range{From: i, To: i}) 92 } 93 } 94 } 95 done: 96 return 97 } 98