Lint fixes (#99)

* Replace a single-character string literal with a character literal.

* Use is_some() instead of comparing with Some(_).

* Add code-quotes around type names in comments.

* Use !...is_empty() instead of len() != 0.

* Tidy up redundant returns.

* Remove redundant .clone() calls.

* Remove unnecessary explicit lifetime parameters.

* Tidy up unnecessary '&'s.

* Add parens to make operator precedence explicit.

* Use debug_assert_eq instead of debug_assert with ==.

* Replace a &Vec argument with a &[...].

* Replace `a = a op b` with `a op= b`.

* Avoid unnecessary closures.

* Avoid .iter() and .iter_mut() for iterating over containers.

* Remove unneeded qualification.

lib/filecheck/src/checker.rs

@@ -66,7 +66,7 @@ impl Directive {
             return Err(Error::Syntax(format!("invalid variable name in regex: {}", rest)));
         }
         let var = rest[0..varlen].to_string();
-        if !rest[varlen..].starts_with("=") {
+        if !rest[varlen..].starts_with('=') {
             return Err(Error::Syntax(format!("expected '=' after variable '{}' in regex: {}",
                                              var,
                                              rest)));
@@ -196,7 +196,7 @@ impl Checker {
             // Check if `pat` matches in `range`.
             state.recorder.directive(dct_idx);
             if let Some((match_begin, match_end)) = state.match_positive(pat, range)? {
-                if let &Directive::Unordered(_) = dct {
+                if let Directive::Unordered(_) = *dct {
                     // This was an unordered unordered match.
                     // Keep track of the largest matched position, but leave `last_ordered` alone.
                     state.max_match = max(state.max_match, match_end);
@@ -231,7 +231,7 @@ impl Checker {
         // Verify any pending `not:` directives after the last ordered directive.
         for (not_idx, not_begin, rx) in nots.drain(..) {
             state.recorder.directive(not_idx);
-            if let Some(_) = rx.find(&text[not_begin..]) {
+            if rx.find(&text[not_begin..]).is_some() {
                 // Matched `not:` pattern.
                 // TODO: Use matched range for an error message.
                 return Ok(false);

lib/filecheck/src/lib.rs

@@ -4,8 +4,8 @@
 //! A list of directives is typically extracted from a file containing a test case. The test case
 //! is then run through the program under test, and its output matched against the directives.
 //!
-//! See the [CheckerBuilder](struct.CheckerBuilder.html) and [Checker](struct.Checker.html) types
-//! for the main library API.
+//! See the [`CheckerBuilder`](struct.CheckerBuilder.html) and [`Checker`](struct.Checker.html)
+//! types for the main library API.
 //!
 //! # Directives
 //!