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, 294, 728, 163, 164, X,
14 292, 167, 168, 304, 350, 286, 308, 173, X, 379, 176, 295, 178, 179, 180, 181, 293, 183, 184,
15 305, 351, 287, 309, 189, X, 380, 192, 193, 194, X, 196, 266, 264, 199, 200, 201, 202, 203, 204,
16 205, 206, 207, X, 209, 210, 211, 212, 288, 214, 215, 284, 217, 218, 219, 220, 364, 348, 223,
17 224, 225, 226, X, 228, 267, 265, 231, 232, 233, 234, 235, 236, 237, 238, 239, X, 241, 242, 243,
18 244, 289, 246, 247, 285, 249, 250, 251, 252, 365, 349, 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, 162, 255, 0, 0, 0, 0, 0, 0, 216, 248, 171, 187, 213, 245, 0, 0, 166,
30 182, 161, 177, 169, 185, 0, 0, 172, 188, 0, 0, 241, 242, 243, 244, 0, 246, 247, 192, 193, 194,
31 0, 196, 0, 0, 199, 176, 0, 178, 179, 180, 181, 0, 183, 0, 249, 250, 251, 252, 0, 0, 0, 0, 221,
32 253, 0, 0, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144,
33 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 0, 0, 163, 164,
34 0, 0, 167, 168, 0, 0, 0, 0, 173, 0, 0, 0, 175, 191, 0, 0, 0, 209, 210, 211, 212, 0, 214, 215,
35 200, 201, 202, 203, 204, 205, 206, 207, 184, 0, 0, 0, 0, 189, 0, 0, 217, 218, 219, 220, 0, 0,
36 223, 224, 225, 226, 0, 228, 0, 0, 231, 232, 233, 234, 235, 236, 237, 238, 239, 198, 230, 197,
37 229, 0, 0, 0, 0, 222, 254, 170, 186,
38]; #[cfg(not(feature = "no-optimized-legacy-encoding"))]
41const BACKWARD_TABLE_UPPER: &[u16] = &[
42 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 72, 80, 88, 96, 104, 112, 51, 141, 43, 133,
43 125, 148, 156, 164, 35, 59, 0, 172, 0, 12, 20, 0, 28, 0, 0, 0, 0, 176, 0, 64, 0, 118, 0, 0, 0,
44 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
45 0, 0, 0, 0, 0, 0, 0, 0, 8,
46]; #[inline]
50#[cfg(not(feature = "no-optimized-legacy-encoding"))]
51pub fn backward(code: u32) -> u8 {
52 let offset = (code >> 3) as usize;
53 let offset = if offset < 92 {BACKWARD_TABLE_UPPER[offset] as usize} else {0};
54 BACKWARD_TABLE_LOWER[offset + ((code & 7) as usize)]
55}
56
57#[cfg(feature = "no-optimized-legacy-encoding")]
59pub fn backward(code: u32) -> u8 {
60 if code > 729 || ((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}