Auto merge of #23682 - tamird:DRY-is-empty, r=alexcrichton

r? @alexcrichton 

10 files changed, 18 insertions, 18 deletions

diff --git a/src/libsyntax/ext/asm.rs b/src/libsyntax/ext/asm.rs
index f2b45d89f73..69159690328 100644
--- a/src/libsyntax/ext/asm.rs
+++ b/src/libsyntax/ext/asm.rs
@@ -90,7 +90,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                       p.token != token::Colon &&
                       p.token != token::ModSep {
 
-                    if outputs.len() != 0 {
+                    if !outputs.is_empty() {
                         panictry!(p.eat(&token::Comma));
                     }
 
@@ -130,7 +130,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                       p.token != token::Colon &&
                       p.token != token::ModSep {
 
-                    if inputs.len() != 0 {
+                    if !inputs.is_empty() {
                         panictry!(p.eat(&token::Comma));
                     }
 
@@ -154,7 +154,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                       p.token != token::Colon &&
                       p.token != token::ModSep {
 
-                    if clobs.len() != 0 {
+                    if !clobs.is_empty() {
                         panictry!(p.eat(&token::Comma));
                     }
 
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 9994fad3e31..9e36c75dda4 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -774,7 +774,7 @@ pub fn check_zero_tts(cx: &ExtCtxt,
                       sp: Span,
                       tts: &[ast::TokenTree],
                       name: &str) {
-    if tts.len() != 0 {
+    if !tts.is_empty() {
         cx.span_err(sp, &format!("{} takes no arguments", name));
     }
 }
diff --git a/src/libsyntax/ext/deriving/clone.rs b/src/libsyntax/ext/deriving/clone.rs
index f89f3ab55f3..95eb68ca0d3 100644
--- a/src/libsyntax/ext/deriving/clone.rs
+++ b/src/libsyntax/ext/deriving/clone.rs
@@ -89,7 +89,7 @@ fn cs_clone(
         }
     }
 
-    if all_fields.len() >= 1 && all_fields[0].name.is_none() {
+    if !all_fields.is_empty() && all_fields[0].name.is_none() {
         // enum-like
         let subcalls = all_fields.iter().map(subcall).collect();
         let path = cx.expr_path(ctor_path);
diff --git a/src/libsyntax/ext/deriving/encodable.rs b/src/libsyntax/ext/deriving/encodable.rs
index 06255f46779..6425e6a28ec 100644
--- a/src/libsyntax/ext/deriving/encodable.rs
+++ b/src/libsyntax/ext/deriving/encodable.rs
@@ -240,7 +240,7 @@ fn encodable_substructure(cx: &mut ExtCtxt, trait_span: Span,
             let encoder = cx.expr_ident(trait_span, blkarg);
             let emit_variant_arg = cx.ident_of("emit_enum_variant_arg");
             let mut stmts = Vec::new();
-            if fields.len() > 0 {
+            if !fields.is_empty() {
                 let last = fields.len() - 1;
                 for (i, &FieldInfo { ref self_, span, .. }) in fields.iter().enumerate() {
                     let enc = cx.expr_method_call(span, self_.clone(),
diff --git a/src/libsyntax/ext/deriving/generic/mod.rs b/src/libsyntax/ext/deriving/generic/mod.rs
index ac96375095e..7f6f29df530 100644
--- a/src/libsyntax/ext/deriving/generic/mod.rs
+++ b/src/libsyntax/ext/deriving/generic/mod.rs
@@ -912,7 +912,7 @@ impl<'a> MethodDef<'a> {
         }
 
         // transpose raw_fields
-        let fields = if raw_fields.len() > 0 {
+        let fields = if !raw_fields.is_empty() {
             let mut raw_fields = raw_fields.into_iter().map(|v| v.into_iter());
             let first_field = raw_fields.next().unwrap();
             let mut other_fields: Vec<vec::IntoIter<(Span, Option<Ident>, P<Expr>)>>
@@ -1248,7 +1248,7 @@ impl<'a> MethodDef<'a> {
 
             match_arms.push(catch_all_match_arm);
 
-        } else if variants.len() == 0 {
+        } else if variants.is_empty() {
             // As an additional wrinkle, For a zero-variant enum A,
             // currently the compiler
             // will accept `fn (a: &Self) { match   *a   { } }`
diff --git a/src/libsyntax/ext/env.rs b/src/libsyntax/ext/env.rs
index f72303985e7..2ca74644b3b 100644
--- a/src/libsyntax/ext/env.rs
+++ b/src/libsyntax/ext/env.rs
@@ -65,7 +65,7 @@ pub fn expand_option_env<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenT
 pub fn expand_env<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                        -> Box<base::MacResult+'cx> {
     let mut exprs = match get_exprs_from_tts(cx, sp, tts) {
-        Some(ref exprs) if exprs.len() == 0 => {
+        Some(ref exprs) if exprs.is_empty() => {
             cx.span_err(sp, "env! takes 1 or 2 arguments");
             return DummyResult::expr(sp);
         }
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index b65798b8a49..74ec219af15 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -841,7 +841,7 @@ fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroE
 fn expand_arm(arm: ast::Arm, fld: &mut MacroExpander) -> ast::Arm {
     // expand pats... they might contain macro uses:
     let expanded_pats = arm.pats.move_map(|pat| fld.fold_pat(pat));
-    if expanded_pats.len() == 0 {
+    if expanded_pats.is_empty() {
         panic!("encountered match arm with 0 patterns");
     }
     // all of the pats must have the same set of bindings, so use the
@@ -1887,7 +1887,7 @@ mod test {
             let binding_name = mtwt::resolve(bindings[binding_idx]);
             let binding_marks = mtwt::marksof(bindings[binding_idx].ctxt, invalid_name);
             // shouldmatch can't name varrefs that don't exist:
-            assert!((shouldmatch.len() == 0) ||
+            assert!((shouldmatch.is_empty()) ||
                     (varrefs.len() > *shouldmatch.iter().max().unwrap()));
             for (idx,varref) in varrefs.iter().enumerate() {
                 let print_hygiene_debug_info = || {
diff --git a/src/libsyntax/ext/format.rs b/src/libsyntax/ext/format.rs
index 374f6fa5040..4fe5ab15545 100644
--- a/src/libsyntax/ext/format.rs
+++ b/src/libsyntax/ext/format.rs
@@ -688,7 +688,7 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt, sp: Span,
     loop {
         match parser.next() {
             Some(piece) => {
-                if parser.errors.len() > 0 { break }
+                if !parser.errors.is_empty() { break }
                 cx.verify_piece(&piece);
                 match cx.trans_piece(&piece) {
                     Some(piece) => {
diff --git a/src/libsyntax/ext/mtwt.rs b/src/libsyntax/ext/mtwt.rs
index f514f72d565..ce83b84efee 100644
--- a/src/libsyntax/ext/mtwt.rs
+++ b/src/libsyntax/ext/mtwt.rs
@@ -266,7 +266,7 @@ pub fn outer_mark(ctxt: SyntaxContext) -> Mrk {
 /// Push a name... unless it matches the one on top, in which
 /// case pop and discard (so two of the same marks cancel)
 fn xor_push(marks: &mut Vec<Mrk>, mark: Mrk) {
-    if (marks.len() > 0) && (*marks.last().unwrap() == mark) {
+    if (!marks.is_empty()) && (*marks.last().unwrap() == mark) {
         marks.pop().unwrap();
     } else {
         marks.push(mark);
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index 4e0b74401a2..9c3a556b210 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -457,7 +457,7 @@ pub fn parse(sess: &ParseSess,
                 return Failure(sp, "unexpected end of macro invocation".to_string());
             }
         } else {
-            if (bb_eis.len() > 0 && next_eis.len() > 0)
+            if (!bb_eis.is_empty() && !next_eis.is_empty())
                 || bb_eis.len() > 1 {
                 let nts = bb_eis.iter().map(|ei| {
                     match ei.top_elts.get_tt(ei.idx) {
@@ -472,12 +472,12 @@ pub fn parse(sess: &ParseSess,
                     "local ambiguity: multiple parsing options: \
                      built-in NTs {} or {} other options.",
                     nts, next_eis.len()).to_string());
-            } else if bb_eis.len() == 0 && next_eis.len() == 0 {
+            } else if bb_eis.is_empty() && next_eis.is_empty() {
                 return Failure(sp, format!("no rules expected the token `{}`",
                             pprust::token_to_string(&tok)).to_string());
-            } else if next_eis.len() > 0 {
+            } else if !next_eis.is_empty() {
                 /* Now process the next token */
-                while next_eis.len() > 0 {
+                while !next_eis.is_empty() {
                     cur_eis.push(next_eis.pop().unwrap());
                 }
                 rdr.next_token();
@@ -504,7 +504,7 @@ pub fn parse(sess: &ParseSess,
             }
         }
 
-        assert!(cur_eis.len() > 0);
+        assert!(!cur_eis.is_empty());
     }
 }