[fix](trx-ftx): clear decoder warnings

Quiet compiler and clippy warnings in the translated decoder modules.

Co-authored-by: OpenAI Codex <codex@openai.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/decoders/trx-ftx/src/crc.rs

@@ -37,9 +37,7 @@ pub fn ftx_extract_crc(a91: &[u8]) -> u16 {
 /// `payload` contains 77 bits of payload data, `a91` receives 91 bits (payload + CRC).
 pub fn ftx_add_crc(payload: &[u8], a91: &mut [u8]) {
     // Copy 77 bits of payload data
-    for i in 0..10 {
-        a91[i] = payload[i];
-    }
+    a91[..10].copy_from_slice(&payload[..10]);
 
     // Clear 3 bits after the payload to make 82 bits
     a91[9] &= 0xF8;

src/decoders/trx-ftx/src/decode.rs

@@ -252,7 +252,7 @@ pub fn ftx_find_candidates(wf: &Waterfall, max_candidates: usize, min_score: i32
                         ft8_sync_score(wf, &cand)
                     };
 
-                    if score >= min_score as i32 {
+                    if score >= min_score {
                         if heap_size == max_candidates && score > heap[0].score as i32 {
                             heap_size -= 1;
                             heap[0] = heap[heap_size];
@@ -469,7 +469,7 @@ fn ftx_normalize_logl(log174: &mut [f32; FTX_LDPC_N]) {
 
 /// Pack bits into bytes (MSB first).
 pub fn pack_bits(bit_array: &[u8], num_bits: usize, packed: &mut [u8]) {
-    let num_bytes = (num_bits + 7) / 8;
+    let num_bytes = num_bits.div_ceil(8);
     for b in packed[..num_bytes].iter_mut() { *b = 0; }
     let mut mask: u8 = 0x80;
     let mut byte_idx = 0;

src/decoders/trx-ftx/src/encode.rs

@@ -47,7 +47,7 @@ fn encode174(message: &[u8], codeword: &mut [u8]) {
             nsum ^= parity8(message[j] & FTX_LDPC_GENERATOR[i][j]);
         }
 
-        if nsum % 2 != 0 {
+        if !nsum.is_multiple_of(2) {
             codeword[col_idx] |= col_mask;
         }
 

src/decoders/trx-ftx/src/ft2/bitmetrics.rs

@@ -266,10 +266,6 @@ mod tests {
     #[test]
     fn normalize_metric_nonzero() {
         let mut m: Vec<f32> = (0..100).map(|i| (i as f32 - 50.0) * 0.1).collect();
-        let orig_variance: f32 = {
-            let mean: f32 = m.iter().sum::<f32>() / m.len() as f32;
-            m.iter().map(|&v| (v - mean) * (v - mean)).sum::<f32>() / m.len() as f32
-        };
         normalize_metric(&mut m);
         // After normalization, standard deviation should be ~1.0
         let mean: f32 = m.iter().sum::<f32>() / m.len() as f32;

src/decoders/trx-ftx/src/ft2/mod.rs

@@ -296,7 +296,7 @@ impl Ft2Pipeline {
             };
 
             let freq_hz = (bin as f32 + delta) * df + ft2_frequency_offset_hz();
-            if freq_hz < 200.0 || freq_hz > 4910.0 {
+            if !(200.0..=4910.0).contains(&freq_hz) {
                 bin += 1;
                 continue;
             }
@@ -368,7 +368,7 @@ impl Ft2Pipeline {
 
             // Fine refinement
             for idf in (best_idf - 4)..=(best_idf + 4) {
-                if idf < FT2_SYNC_TWEAK_MIN || idf > FT2_SYNC_TWEAK_MAX {
+                if !(FT2_SYNC_TWEAK_MIN..=FT2_SYNC_TWEAK_MAX).contains(&idf) {
                     continue;
                 }
                 for start in (best_start - 5)..=(best_start + 5) {
@@ -427,7 +427,7 @@ impl Ft2Pipeline {
         let mut best_idf = hit.idf;
 
         for idf in (hit.idf - 4)..=(hit.idf + 4) {
-            if idf < FT2_SYNC_TWEAK_MIN || idf > FT2_SYNC_TWEAK_MAX {
+            if !(FT2_SYNC_TWEAK_MIN..=FT2_SYNC_TWEAK_MAX).contains(&idf) {
                 continue;
             }
             for start in (hit.start - 5)..=(hit.start + 5) {
@@ -463,10 +463,7 @@ impl Ft2Pipeline {
         extract_signal_region(&cb[..produced2], best_start, &mut signal);
 
         // Extract bit metrics
-        let bitmetrics = match bitmetrics::extract_bitmetrics_raw(&signal) {
-            Some(bm) => bm,
-            None => return None,
-        };
+        let bitmetrics = bitmetrics::extract_bitmetrics_raw(&signal)?;
 
         // Sync quality check using known Costas bit patterns
         let sync_bits_a: [u8; 8] = [0, 0, 0, 1, 1, 0, 1, 1];

src/decoders/trx-ftx/src/ft2/osd.rs

@@ -69,7 +69,7 @@ fn platanh(x: f32) -> f32 {
 
 /// Pack bit array into bytes (MSB first).
 fn pack_bits91(bit_array: &[u8], num_bits: usize, packed: &mut [u8]) {
-    let num_bytes = (num_bits + 7) / 8;
+    let num_bytes = num_bits.div_ceil(8);
     for b in packed[..num_bytes].iter_mut() {
         *b = 0;
     }
@@ -364,9 +364,7 @@ pub fn osd174_91(
             // Swap columns id and col
             if col != id {
                 for row in 0..k {
-                    let a = genmrb[row * n + id];
-                    genmrb[row * n + id] = genmrb[row * n + col];
-                    genmrb[row * n + col] = a;
+                    genmrb.swap(row * n + id, row * n + col);
                 }
                 indices.swap(id, col);
             }

src/decoders/trx-ftx/src/ft2/sync.rs

@@ -152,7 +152,7 @@ pub fn refine_sync(
     let mut best_idf = center_idf;
 
     for idf in (center_idf - idf_range)..=(center_idf + idf_range) {
-        if idf < FT2_SYNC_TWEAK_MIN || idf > FT2_SYNC_TWEAK_MAX {
+        if !(FT2_SYNC_TWEAK_MIN..=FT2_SYNC_TWEAK_MAX).contains(&idf) {
             continue;
         }
         for start in (center_start - start_range)..=(center_start + start_range) {

src/decoders/trx-ftx/src/lib.rs

@@ -6,12 +6,23 @@ pub mod protocol;
 pub mod constants;
 pub mod crc;
 pub mod text;
+#[allow(clippy::manual_memcpy, clippy::needless_range_loop)]
 pub mod ldpc;
+#[allow(clippy::needless_range_loop)]
 pub mod encode;
 pub mod callsign_hash;
+#[allow(clippy::explicit_counter_loop, clippy::needless_range_loop)]
 pub mod message;
+#[allow(dead_code)]
 pub mod monitor;
+#[allow(dead_code, clippy::needless_range_loop)]
 pub mod decode;
+#[allow(
+    dead_code,
+    clippy::manual_memcpy,
+    clippy::needless_range_loop,
+    clippy::too_many_arguments
+)]
 pub mod ft2;
 mod decoder;
 

src/decoders/trx-ftx/src/message.rs

@@ -179,18 +179,13 @@ fn is_space(c: u8) -> bool {
 fn copy_token(input: &str) -> (&str, String) {
     let input = input.trim_start();
     let end = input
-        .find(|c: char| c == ' ')
+        .find(' ')
         .unwrap_or(input.len());
     let token = &input[..end];
     let rest = &input[end..].trim_start();
     (rest, token.to_string())
 }
 
-/// Trim leading and trailing whitespace.
-fn trim(s: &str) -> &str {
-    s.trim()
-}
-
 /// Trim leading occurrences of a specific character.
 fn trim_front(s: &str, c: char) -> &str {
     s.trim_start_matches(c)
@@ -405,7 +400,7 @@ fn pack28(
         return Some(((NTOKENS + MAX22) as i32 + n28, ip));
     }
 
-    if length >= 3 && length <= 11 {
+    if (3..=11).contains(&length) {
         // Non-standard callsign: compute 22-bit hash
         let (n22, _, _) = save_callsign(hash_table, callsign)?;
         ip = 0;
@@ -616,11 +611,13 @@ fn packgrid(grid4: &str) -> u16 {
     if bytes[0] == b'R' {
         let dd = dd_to_int(&grid4[1..]);
         let irpt = (35 + dd) as u16;
-        return (MAXGRID4 + irpt) | 0x8000; // ir = 1
+        // ir = 1
+        (MAXGRID4 + irpt) | 0x8000
     } else {
         let dd = dd_to_int(grid4);
         let irpt = (35 + dd) as u16;
-        return MAXGRID4 + irpt; // ir = 0
+        // ir = 0
+        MAXGRID4 + irpt
     }
 }
 
@@ -688,9 +685,6 @@ pub fn ftx_message_encode(
     message_text: &str,
 ) -> FtxMessageRc {
     let mut call_to: String;
-    let call_de: String;
-    let extra: String;
-
     let mut parse_pos = message_text;
     let is_cq = starts_with(message_text, "CQ ");
 
@@ -715,11 +709,11 @@ pub fn ftx_message_encode(
     }
 
     let (rest, token) = copy_token(parse_pos);
-    call_de = token;
+    let call_de: String = token;
     parse_pos = rest;
 
     let (rest, token) = copy_token(parse_pos);
-    extra = token;
+    let extra: String = token;
     parse_pos = rest;
 
     // Check token lengths
@@ -1490,7 +1484,7 @@ mod tests {
         // i3 is in bits 74..76: payload[9] bits 5..3
         // For i3=0, n3=5 (binary 101): bit2=1, bit1=0, bit0=1
         msg.payload[8] = (msg.payload[8] & 0xFE) | 1; // n3 bit2 = 1
-        msg.payload[9] = (0b01 << 6); // n3 bits 1..0 = 01, i3 = 0
+        msg.payload[9] = 0b01 << 6; // n3 bits 1..0 = 01, i3 = 0
 
         assert_eq!(msg.get_type(), FtxMessageType::Telemetry);
 

src/decoders/trx-ftx/src/protocol.rs

@@ -104,8 +104,8 @@ pub const FT2_SYNC_OFFSET: usize = FT4_SYNC_OFFSET;
 pub const FTX_LDPC_N: usize = 174;
 pub const FTX_LDPC_K: usize = 91;
 pub const FTX_LDPC_M: usize = 83;
-pub const FTX_LDPC_N_BYTES: usize = (FTX_LDPC_N + 7) / 8;
-pub const FTX_LDPC_K_BYTES: usize = (FTX_LDPC_K + 7) / 8;
+pub const FTX_LDPC_N_BYTES: usize = FTX_LDPC_N.div_ceil(8);
+pub const FTX_LDPC_K_BYTES: usize = FTX_LDPC_K.div_ceil(8);
 
 // CRC parameters
 pub const FT8_CRC_POLYNOMIAL: u16 = 0x2757;

src/decoders/trx-ftx/src/text.rs

@@ -92,7 +92,7 @@ pub fn nchar(c: char, table: CharTable) -> Option<i32> {
 
     // Digits
     if table != CharTable::LettersSpace {
-        if c >= '0' && c <= '9' {
+        if c.is_ascii_digit() {
             return Some(n + (c as i32 - '0' as i32));
         }
         n += 10;
@@ -100,7 +100,7 @@ pub fn nchar(c: char, table: CharTable) -> Option<i32> {
 
     // Letters
     if table != CharTable::Numeric {
-        if c >= 'A' && c <= 'Z' {
+        if c.is_ascii_uppercase() {
             return Some(n + (c as i32 - 'A' as i32));
         }
         n += 26;
@@ -132,7 +132,7 @@ pub fn nchar(c: char, table: CharTable) -> Option<i32> {
 /// Convert a character to uppercase ASCII. Non-letter characters are returned
 /// unchanged.
 pub fn to_upper(c: char) -> char {
-    if c >= 'a' && c <= 'z' {
+    if c.is_ascii_lowercase() {
         char::from(c as u8 - b'a' + b'A')
     } else {
         c