parser: remove an allocation, fix new clippy warnings

Author: algorithmiker

src/backend/muxml/mod.rs

@@ -231,7 +231,7 @@ impl MuxmlGenerator {
 
         let data_range = &self.parsed.measures[measure_idx].data_range;
         let ticks_in_measure = rlen(data_range) / 6;
-        debug_assert!(rlen(data_range) % 6 == 0);
+        debug_assert!(rlen(data_range).is_multiple_of(6));
 
         // Length of actual content in measure. `remove_space_between_notes` will reduce this for example
         let mut measure_content_len = ticks_in_measure;
@@ -299,7 +299,7 @@ impl MuxmlGenerator {
         }
         // Try to simplify e.g 8/8 to 4/4
         let (mut measure_enumerator, mut measure_denominator) = (measure_content_len, 8);
-        if self.settings.simplify_time_signature && measure_content_len % 2 == 0 {
+        if self.settings.simplify_time_signature && measure_content_len.is_multiple_of(2) {
             measure_enumerator /= 2;
             measure_denominator /= 2;
         }

src/parser/parser.rs

@@ -74,6 +74,11 @@ impl ParseResult {
         bufs.concat()
     }
 }
+
+/// stupid helper function, used because Rust doesn't currently let you collect into an array
+fn line_indices(idx: usize) -> [usize; 6] {
+    [idx, idx + 1, idx + 2, idx + 3, idx + 4, idx + 5]
+}
 pub fn parse<L: ParseLines>(lines: &L) -> ParseResult {
     let mut r = ParseResult::new();
     let mut part_first_line = 0;
@@ -94,7 +99,7 @@ pub fn parse<L: ParseLines>(lines: &L) -> ParseResult {
         let _part = span!(Level::DEBUG, "parsing part", ?range);
         let _part = _part.enter();
         r.offsets.push((part_first_line as u32, r.tick_stream.len() as u32));
-        let mut part: Vec<&str> = range.map(|s| lines.get_line(s).trim()).collect(); // TODO: check if this is slow
+        let mut part: [&str; 6] = line_indices(part_first_line).map(|s| lines.get_line(s).trim()); // TODO: check if this is slow
 
         // The current tick in THIS PART
         let mut tick = 0;
@@ -311,7 +316,7 @@ pub fn source_location_from_stream(r: &ParseResult, tick_location: u32) -> (u32,
     (actual_line, offset_on_line)
 }
 
-pub fn dump_source(input: &Vec<&str>) -> String {
+pub fn dump_source(input: &[&str]) -> String {
     use itertools::Itertools;
     std::iter::once(&"").chain(input.iter()).join("\n")
 }