From 0624b939459728f0c36ebc695df2b4a857bd32dd Mon Sep 17 00:00:00 2001
From: "Hikaru Terazono (3c1u)" <3c1u@vulpesgames.tokyo>
Date: Sun, 15 Dec 2019 01:03:42 +0900
Subject: [PATCH] clippy

---
 src/codegen.rs | 15 +++++++++------
 src/parser.rs  |  5 ++---
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/codegen.rs b/src/codegen.rs
index 8962eae..eb5ffb2 100644
--- a/src/codegen.rs
+++ b/src/codegen.rs
@@ -31,13 +31,17 @@ pub struct Codegen<'c> {
 extern "C" fn bfrs_get_char() -> u8 {
     let mut input = std::io::stdin();
     let mut buf = [0u8];
-    input.read(&mut buf).unwrap();
+
+    if input.read(&mut buf).unwrap() == 0 {
+        return 0xFF; // EOF
+    }
+
     buf[0]
 }
 
 extern "C" fn bfrs_print_char(c: u8) {
     let mut out = std::io::stdout();
-    out.write(&[c]).unwrap();
+    out.write_all(&[c]).unwrap();
     out.flush().unwrap();
 }
 
@@ -167,7 +171,7 @@ impl<'c> Codegen<'c> {
         match operation {
             BfAST::LoopBlock(v) => {
                 // 特殊パターンの高速化
-                if v.len() == 0 {
+                if v.is_empty() {
                     return Ok(());
                 } else if v.len() == 1 {
                     if let BfAST::SubOp(k) = v[0] {
@@ -189,7 +193,7 @@ impl<'c> Codegen<'c> {
                         return Ok(());
                     }
                 } else if v.len() == 3 {
-                    if let &[BfAST::AddPtr(j), BfAST::AddOp(k), BfAST::SubPtr(l)] = &v[0..3] {
+                    if let [BfAST::AddPtr(j), BfAST::AddOp(k), BfAST::SubPtr(l)] = v[0..3] {
                         if j == l {
                             let rhs = self.get_current(value_table, counter);
 
@@ -221,8 +225,7 @@ impl<'c> Codegen<'c> {
 
                             return Ok(());
                         }
-                    } else if let &[BfAST::SubPtr(j), BfAST::AddOp(k), BfAST::AddPtr(l)] = &v[0..3]
-                    {
+                    } else if let [BfAST::SubPtr(j), BfAST::AddOp(k), BfAST::AddPtr(l)] = v[0..3] {
                         if j == l {
                             let rhs = self.get_current(value_table, counter);
 
diff --git a/src/parser.rs b/src/parser.rs
index 5d5617b..c360d9f 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -138,11 +138,10 @@ fn visit_program(p: Pair<'_, Rule>, v: &mut Vec<BfAST>) -> Result<()> {
 }
 
 pub fn parse<P: AsRef<str>>(program: P) -> Result<Vec<BfAST>> {
-    let pairs = BfParser::parse(Rule::program, program.as_ref())?;
+    let mut pairs = BfParser::parse(Rule::program, program.as_ref())?;
     let program = pairs
-        .into_iter()
         .next()
-        .ok_or(Error::ice("no matching program"))?;
+        .ok_or_else(|| Error::ice("no matching program"))?;
 
     let mut program_out = vec![];
     visit_program(program, &mut program_out)?;