Zack Williams | e940c7a | 2019-08-21 14:25:39 -0700 | [diff] [blame] | 1 | package flags |
| 2 | |
| 3 | import ( |
| 4 | "strconv" |
| 5 | ) |
| 6 | |
| 7 | type multiTag struct { |
| 8 | value string |
| 9 | cache map[string][]string |
| 10 | } |
| 11 | |
| 12 | func newMultiTag(v string) multiTag { |
| 13 | return multiTag{ |
| 14 | value: v, |
| 15 | } |
| 16 | } |
| 17 | |
| 18 | func (x *multiTag) scan() (map[string][]string, error) { |
| 19 | v := x.value |
| 20 | |
| 21 | ret := make(map[string][]string) |
| 22 | |
| 23 | // This is mostly copied from reflect.StructTag.Get |
| 24 | for v != "" { |
| 25 | i := 0 |
| 26 | |
| 27 | // Skip whitespace |
| 28 | for i < len(v) && v[i] == ' ' { |
| 29 | i++ |
| 30 | } |
| 31 | |
| 32 | v = v[i:] |
| 33 | |
| 34 | if v == "" { |
| 35 | break |
| 36 | } |
| 37 | |
| 38 | // Scan to colon to find key |
| 39 | i = 0 |
| 40 | |
| 41 | for i < len(v) && v[i] != ' ' && v[i] != ':' && v[i] != '"' { |
| 42 | i++ |
| 43 | } |
| 44 | |
| 45 | if i >= len(v) { |
| 46 | return nil, newErrorf(ErrTag, "expected `:' after key name, but got end of tag (in `%v`)", x.value) |
| 47 | } |
| 48 | |
| 49 | if v[i] != ':' { |
| 50 | return nil, newErrorf(ErrTag, "expected `:' after key name, but got `%v' (in `%v`)", v[i], x.value) |
| 51 | } |
| 52 | |
| 53 | if i+1 >= len(v) { |
| 54 | return nil, newErrorf(ErrTag, "expected `\"' to start tag value at end of tag (in `%v`)", x.value) |
| 55 | } |
| 56 | |
| 57 | if v[i+1] != '"' { |
| 58 | return nil, newErrorf(ErrTag, "expected `\"' to start tag value, but got `%v' (in `%v`)", v[i+1], x.value) |
| 59 | } |
| 60 | |
| 61 | name := v[:i] |
| 62 | v = v[i+1:] |
| 63 | |
| 64 | // Scan quoted string to find value |
| 65 | i = 1 |
| 66 | |
| 67 | for i < len(v) && v[i] != '"' { |
| 68 | if v[i] == '\n' { |
| 69 | return nil, newErrorf(ErrTag, "unexpected newline in tag value `%v' (in `%v`)", name, x.value) |
| 70 | } |
| 71 | |
| 72 | if v[i] == '\\' { |
| 73 | i++ |
| 74 | } |
| 75 | i++ |
| 76 | } |
| 77 | |
| 78 | if i >= len(v) { |
| 79 | return nil, newErrorf(ErrTag, "expected end of tag value `\"' at end of tag (in `%v`)", x.value) |
| 80 | } |
| 81 | |
| 82 | val, err := strconv.Unquote(v[:i+1]) |
| 83 | |
| 84 | if err != nil { |
| 85 | return nil, newErrorf(ErrTag, "Malformed value of tag `%v:%v` => %v (in `%v`)", name, v[:i+1], err, x.value) |
| 86 | } |
| 87 | |
| 88 | v = v[i+1:] |
| 89 | |
| 90 | ret[name] = append(ret[name], val) |
| 91 | } |
| 92 | |
| 93 | return ret, nil |
| 94 | } |
| 95 | |
| 96 | func (x *multiTag) Parse() error { |
| 97 | vals, err := x.scan() |
| 98 | x.cache = vals |
| 99 | |
| 100 | return err |
| 101 | } |
| 102 | |
| 103 | func (x *multiTag) cached() map[string][]string { |
| 104 | if x.cache == nil { |
| 105 | cache, _ := x.scan() |
| 106 | |
| 107 | if cache == nil { |
| 108 | cache = make(map[string][]string) |
| 109 | } |
| 110 | |
| 111 | x.cache = cache |
| 112 | } |
| 113 | |
| 114 | return x.cache |
| 115 | } |
| 116 | |
| 117 | func (x *multiTag) Get(key string) string { |
| 118 | c := x.cached() |
| 119 | |
| 120 | if v, ok := c[key]; ok { |
| 121 | return v[len(v)-1] |
| 122 | } |
| 123 | |
| 124 | return "" |
| 125 | } |
| 126 | |
| 127 | func (x *multiTag) GetMany(key string) []string { |
| 128 | c := x.cached() |
| 129 | return c[key] |
| 130 | } |
| 131 | |
| 132 | func (x *multiTag) Set(key string, value string) { |
| 133 | c := x.cached() |
| 134 | c[key] = []string{value} |
| 135 | } |
| 136 | |
| 137 | func (x *multiTag) SetMany(key string, value []string) { |
| 138 | c := x.cached() |
| 139 | c[key] = value |
| 140 | } |