1#[allow(dead_code)] const X: u16 = 0xffff;
10
11const FORWARD_TABLE: &[u16] = &[
12 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146,
13 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 260, 312, 342, 164, 296,
14 315, 167, 168, 352, 274, 290, 358, 173, 381, 175, 176, 261, 731, 343, 180, 297, 316, 711, 184,
15 353, 275, 291, 359, 330, 382, 331, 256, 193, 194, 195, 196, 197, 198, 302, 268, 201, 280, 203,
16 278, 205, 206, 298, 272, 325, 332, 310, 212, 213, 214, 215, 216, 370, 218, 219, 220, 360, 362,
17 223, 257, 225, 226, 227, 228, 229, 230, 303, 269, 233, 281, 235, 279, 237, 238, 299, 273, 326,
18 333, 311, 244, 245, 246, 247, 248, 371, 250, 251, 252, 361, 363, 729,
19]; #[inline]
23pub fn forward(code: u8) -> u16 {
24 FORWARD_TABLE[(code - 0x80) as usize]
25}
26
27#[cfg(not(feature = "no-optimized-legacy-encoding"))]
28const BACKWARD_TABLE_LOWER: &[u8] = &[
29 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 208, 240, 170, 186, 0, 0, 204, 236, 202, 234,
30 0, 0, 0, 0, 0, 0, 163, 179, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 0, 178, 0, 0, 0, 0, 212, 213, 214,
31 215, 216, 0, 218, 219, 220, 0, 0, 223, 169, 185, 0, 0, 0, 0, 172, 188, 221, 253, 222, 254, 0,
32 0, 0, 0, 0, 209, 241, 0, 0, 0, 189, 191, 210, 242, 0, 0, 193, 194, 195, 196, 197, 198, 0, 0,
33 201, 0, 203, 0, 205, 206, 0, 225, 226, 227, 228, 229, 230, 0, 0, 233, 0, 235, 0, 237, 238, 0,
34 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 160, 0, 0, 0,
35 164, 0, 0, 167, 168, 0, 0, 0, 0, 173, 0, 175, 192, 224, 0, 0, 161, 177, 0, 0, 0, 0, 0, 0, 200,
36 232, 0, 0, 217, 249, 0, 0, 0, 0, 0, 0, 0, 0, 0, 174, 190, 0, 144, 145, 146, 147, 148, 149, 150,
37 151, 152, 153, 154, 155, 156, 157, 158, 159, 176, 0, 0, 0, 180, 0, 0, 0, 184, 0, 0, 0, 0, 0, 0,
38 0, 183, 0, 0, 0, 0, 0, 0, 0, 0, 211, 243, 162, 0, 0, 166, 182, 0, 0, 0, 0, 244, 245, 246, 247,
39 248, 0, 250, 251, 252, 0, 0, 0, 171, 187, 0, 0, 0, 0, 165, 181, 207, 239, 0, 0, 199, 231,
40]; #[cfg(not(feature = "no-optimized-legacy-encoding"))]
43const BACKWARD_TABLE_UPPER: &[u16] = &[
44 0, 0, 0, 0, 0, 0, 0, 0, 120, 182, 136, 198, 89, 46, 104, 230, 152, 16, 244, 217, 74, 26, 62,
45 166, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 207, 34,
46]; #[inline]
50#[cfg(not(feature = "no-optimized-legacy-encoding"))]
51pub fn backward(code: u32) -> u8 {
52 let offset = (code >> 4) as usize;
53 let offset = if offset < 46 {BACKWARD_TABLE_UPPER[offset] as usize} else {0};
54 BACKWARD_TABLE_LOWER[offset + ((code & 15) as usize)]
55}
56
57#[cfg(feature = "no-optimized-legacy-encoding")]
59pub fn backward(code: u32) -> u8 {
60 if code > 731 || ((0x400ff0u32 >> (code >> 5)) & 1) == 0 { return 0; }
61 let code = code as u16;
62 for i in 0..0x80 {
63 if FORWARD_TABLE[i as usize] == code { return 0x80 + i; }
64 }
65 0
66}
67
68#[cfg(test)]
69encoding_index_tests::single_byte_tests! {
70}