Positive case of len() -> is_empty()

`s/(?<!\{ self)(?<=\.)len\(\) == 0/is_empty()/g`

Author: tamird

src/compiletest/runtest.rs

@@ -864,7 +864,7 @@ fn check_debugger_output(debugger_run_result: &ProcRes, check_lines: &[String])
                 }
                 first = false;
             }
-            if !failed && rest.len() == 0 {
+            if !failed && rest.is_empty() {
                 i += 1;
             }
             if i == num_check_lines {
@@ -1662,7 +1662,7 @@ fn _arm_push_aux_shared_library(config: &Config, testfile: &Path) {
 // codegen tests (vs. clang)
 
 fn append_suffix_to_stem(p: &Path, suffix: &str) -> PathBuf {
-    if suffix.len() == 0 {
+    if suffix.is_empty() {
         p.to_path_buf()
     } else {
         let mut stem = p.file_stem().unwrap().to_os_string();

src/doc/reference.md

@@ -3788,7 +3788,7 @@ its type parameters are types:
 
 ```ignore
 fn map<A: Clone, B: Clone>(f: |A| -> B, xs: &[A]) -> Vec<B> {
-    if xs.len() == 0 {
+    if xs.is_empty() {
        return vec![];
     }
     let first: B = f(xs[0].clone());

src/libcollections/btree/map.rs

@@ -692,7 +692,7 @@ mod stack {
                         // We've reached the root, so no matter what, we're done. We manually
                         // access the root via the tree itself to avoid creating any dangling
                         // pointers.
-                        if self.map.root.len() == 0 && !self.map.root.is_leaf() {
+                        if self.map.root.is_empty() && !self.map.root.is_leaf() {
                             // We've emptied out the root, so make its only child the new root.
                             // If it's a leaf, we just let it become empty.
                             self.map.depth -= 1;

src/libcollections/btree/node.rs

@@ -1097,7 +1097,7 @@ impl<K, V> Node<K, V> {
     /// When a node has no keys or values and only a single edge, extract that edge.
     pub fn hoist_lone_child(&mut self) {
         // Necessary for correctness, but in a private module
-        debug_assert!(self.len() == 0);
+        debug_assert!(self.is_empty());
         debug_assert!(!self.is_leaf());
 
         unsafe {

src/libcore/slice.rs

@@ -204,7 +204,7 @@ impl<T> SliceExt for [T] {
 
     #[inline]
     fn first(&self) -> Option<&T> {
-        if self.len() == 0 { None } else { Some(&self[0]) }
+        if self.is_empty() { None } else { Some(&self[0]) }
     }
 
     #[inline]
@@ -217,7 +217,7 @@ impl<T> SliceExt for [T] {
 
     #[inline]
     fn last(&self) -> Option<&T> {
-        if self.len() == 0 { None } else { Some(&self[self.len() - 1]) }
+        if self.is_empty() { None } else { Some(&self[self.len() - 1]) }
     }
 
     #[inline]
@@ -296,7 +296,7 @@ impl<T> SliceExt for [T] {
 
     #[inline]
     fn first_mut(&mut self) -> Option<&mut T> {
-        if self.len() == 0 { None } else { Some(&mut self[0]) }
+        if self.is_empty() { None } else { Some(&mut self[0]) }
     }
 
     #[inline]
@@ -1306,7 +1306,7 @@ impl<'a, T> Iterator for Chunks<'a, T> {
 
     #[inline]
     fn next(&mut self) -> Option<&'a [T]> {
-        if self.v.len() == 0 {
+        if self.v.is_empty() {
             None
         } else {
             let chunksz = cmp::min(self.v.len(), self.size);
@@ -1318,7 +1318,7 @@ impl<'a, T> Iterator for Chunks<'a, T> {
 
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
-        if self.v.len() == 0 {
+        if self.v.is_empty() {
             (0, Some(0))
         } else {
             let n = self.v.len() / self.size;
@@ -1333,7 +1333,7 @@ impl<'a, T> Iterator for Chunks<'a, T> {
 impl<'a, T> DoubleEndedIterator for Chunks<'a, T> {
     #[inline]
     fn next_back(&mut self) -> Option<&'a [T]> {
-        if self.v.len() == 0 {
+        if self.v.is_empty() {
             None
         } else {
             let remainder = self.v.len() % self.size;
@@ -1384,7 +1384,7 @@ impl<'a, T> Iterator for ChunksMut<'a, T> {
 
     #[inline]
     fn next(&mut self) -> Option<&'a mut [T]> {
-        if self.v.len() == 0 {
+        if self.v.is_empty() {
             None
         } else {
             let sz = cmp::min(self.v.len(), self.chunk_size);
@@ -1397,7 +1397,7 @@ impl<'a, T> Iterator for ChunksMut<'a, T> {
 
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
-        if self.v.len() == 0 {
+        if self.v.is_empty() {
             (0, Some(0))
         } else {
             let n = self.v.len() / self.chunk_size;
@@ -1412,7 +1412,7 @@ impl<'a, T> Iterator for ChunksMut<'a, T> {
 impl<'a, T> DoubleEndedIterator for ChunksMut<'a, T> {
     #[inline]
     fn next_back(&mut self) -> Option<&'a mut [T]> {
-        if self.v.len() == 0 {
+        if self.v.is_empty() {
             None
         } else {
             let remainder = self.v.len() % self.chunk_size;

src/libcore/str/mod.rs

@@ -1119,7 +1119,7 @@ enum OldSearcher {
 impl OldSearcher {
     #[allow(dead_code)]
     fn new(haystack: &[u8], needle: &[u8]) -> OldSearcher {
-        if needle.len() == 0 {
+        if needle.is_empty() {
             // Handle specially
             unimplemented!()
         // FIXME: Tune this.

src/libcore/str/pattern.rs

@@ -457,7 +457,7 @@ fn str_search_step<F, G>(mut m: &mut StrSearcher,
 {
     if m.state.done() {
         SearchStep::Done
-    } else if m.needle.len() == 0 && m.start <= m.end {
+    } else if m.needle.is_empty() && m.start <= m.end {
         // Case for needle == ""
         if let State::Reject(a, b) = m.state.take() {
             SearchStep::Reject(a, b)

src/liblog/directive.rs

@@ -45,7 +45,7 @@ pub fn parse_logging_spec(spec: &str) -> (Vec<LogDirective>, Option<String>) {
         return (dirs, None);
     }
     mods.map(|m| { for s in m.split(',') {
-        if s.len() == 0 { continue }
+        if s.is_empty() { continue }
         let mut parts = s.split('=');
         let (log_level, name) = match (parts.next(), parts.next().map(|s| s.trim()), parts.next()) {
             (Some(part0), None, None) => {

src/librustc/metadata/creader.rs

@@ -80,7 +80,7 @@ pub fn validate_crate_name(sess: Option<&Session>, s: &str, sp: Option<Span>) {
             (None, Some(sess)) => sess.err(s),
         }
     };
-    if s.len() == 0 {
+    if s.is_empty() {
         say("crate name must not be empty");
     }
     for c in s.chars() {

src/librustc/metadata/decoder.rs

@@ -767,7 +767,7 @@ pub fn get_enum_variants<'tcx>(intr: Rc<IdentInterner>, cdata: Cmd, id: ast::Nod
                         get_type(cdata, field_ty.id.node, tcx).ty
                     })
                     .collect();
-                let arg_names = if arg_names.len() == 0 { None } else { Some(arg_names) };
+                let arg_names = if arg_names.is_empty() { None } else { Some(arg_names) };
 
                 (None, arg_tys, arg_names)
             }
@@ -1383,7 +1383,7 @@ pub fn get_dylib_dependency_formats(cdata: Cmd)
 
     debug!("found dylib deps: {}", formats.as_str_slice());
     for spec in formats.as_str_slice().split(',') {
-        if spec.len() == 0 { continue }
+        if spec.is_empty() { continue }
         let cnum = spec.split(':').nth(0).unwrap();
         let link = spec.split(':').nth(1).unwrap();
         let cnum: ast::CrateNum = cnum.parse().unwrap();