Detect encoding from BOM (Byte Order Mark). Returns `Some(encoding)` if a BOM is detected, `None` otherwise.
(content: &[u8])
| 129 | /// |
| 130 | /// Returns `Some(encoding)` if a BOM is detected, `None` otherwise. |
| 131 | fn detect_bom(content: &[u8]) -> Option<Self> { |
| 132 | if content.len() < 2 { |
| 133 | return None; |
| 134 | } |
| 135 | |
| 136 | // UTF-8 BOM: EF BB BF |
| 137 | if content.len() >= 3 && content[0] == 0xEF && content[1] == 0xBB && content[2] == 0xBF { |
| 138 | return Some(Encoding::Utf8); |
| 139 | } |
| 140 | |
| 141 | // UTF-16 LE BOM: FF FE |
| 142 | if content[0] == 0xFF && content[1] == 0xFE { |
| 143 | return Some(Encoding::Utf16Le); |
| 144 | } |
| 145 | |
| 146 | // UTF-16 BE BOM: FE FF |
| 147 | if content[0] == 0xFE && content[1] == 0xFF { |
| 148 | return Some(Encoding::Utf16Be); |
| 149 | } |
| 150 | |
| 151 | None |
| 152 | } |
| 153 | |
| 154 | /// Check if this encoding represents text (not binary). |
| 155 | /// |