style: use is_empty

Author: jeremystucki

src/compile.rs

@@ -110,7 +110,7 @@ impl Compiler {
     /// specified size limit. If the size limit is exceeded, then compilation
     /// stops and returns an error.
     pub fn compile(mut self, exprs: &[Hir]) -> result::Result<Program, Error> {
-        debug_assert!(exprs.len() >= 1);
+        debug_assert!(!exprs.is_empty());
         self.num_exprs = exprs.len();
         if exprs.len() == 1 {
             self.compile_one(&exprs[0])

src/literal/imp.rs

@@ -570,7 +570,7 @@ impl BoyerMooreSearch {
     /// Create a new string searcher, performing whatever
     /// compilation steps are required.
     fn new(pattern: Vec<u8>) -> Self {
-        debug_assert!(pattern.len() > 0);
+        debug_assert!(!pattern.is_empty());
 
         let (g, gi) = Self::select_guard(pattern.as_slice());
         let skip_table = Self::compile_skip_table(pattern.as_slice());