braceIndices returns the first level curly brace indices from a string. It returns an error in case of unbalanced braces.
(s string)
| 282 | // braceIndices returns the first level curly brace indices from a string. |
| 283 | // It returns an error in case of unbalanced braces. |
| 284 | func braceIndices(s string) ([]int, error) { |
| 285 | var level, idx int |
| 286 | var idxs []int |
| 287 | for i := 0; i < len(s); i++ { |
| 288 | switch s[i] { |
| 289 | case '{': |
| 290 | if level++; level == 1 { |
| 291 | idx = i |
| 292 | } |
| 293 | case '}': |
| 294 | if level--; level == 0 { |
| 295 | idxs = append(idxs, idx, i+1) |
| 296 | } else if level < 0 { |
| 297 | return nil, fmt.Errorf("mux: unbalanced braces in %q", s) |
| 298 | } |
| 299 | } |
| 300 | } |
| 301 | if level != 0 { |
| 302 | return nil, fmt.Errorf("mux: unbalanced braces in %q", s) |
| 303 | } |
| 304 | return idxs, nil |
| 305 | } |
| 306 | |
| 307 | // varGroupName builds a capturing group name for the indexed variable. |
| 308 | func varGroupName(idx int) string { |