From 9326dbc3de7fde53db5b34bec3dfbc825c45ee7c Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Sat, 24 Jan 2015 22:52:40 -0500
Subject: [PATCH 1/3] Cleanup cat: open files in for loop header.

---
 src/cat/cat.rs | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/src/cat/cat.rs b/src/cat/cat.rs
index 9e6f179f1..1d8011f74 100644
--- a/src/cat/cat.rs
+++ b/src/cat/cat.rs
@@ -95,11 +95,7 @@ fn write_lines(files: Vec<String>, number: NumberingMode, squeeze_blank: bool,
 
     let mut line_counter: usize = 1;
 
-    for path in files.iter() {
-        let (mut reader, interactive) = match open(path.as_slice()) {
-            Some(f) => f,
-            None => continue,
-        };
+    for (mut reader, interactive) in files.iter().filter_map(|p| open(&p[])) {
 
         let mut in_buf  = [0; 1024 * 31];
         let mut out_buf = [0; 1024 * 64];
@@ -168,11 +164,7 @@ fn write_bytes(files: Vec<String>, number: NumberingMode, squeeze_blank: bool,
 
     let mut line_counter: usize = 1;
 
-    for path in files.iter() {
-        let (mut reader, interactive) = match open(path.as_slice()) {
-            Some(f) => f,
-            None => continue,
-        };
+    for (mut reader, interactive) in files.iter().filter_map(|p| open(&p[])) {
 
         // Flush all 1024 iterations.
         let mut flush_counter = range(0us, 1024);
@@ -246,12 +238,7 @@ fn write_fast(files: Vec<String>) {
     let mut writer = stdout_raw();
     let mut in_buf = [0; 1024 * 64];
 
-    for path in files.iter() {
-        let (mut reader, _) = match open(path.as_slice()) {
-            Some(x) => x,
-            None => continue,
-        };
-
+    for (mut reader, _) in files.iter().filter_map(|p| open(&p[])) {
         loop {
             match reader.read(&mut in_buf) {
                 Ok(n) if n != 0 => {

From 8a101b220309018cc8a03a16f39404d9332db276 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Sat, 24 Jan 2015 22:53:27 -0500
Subject: [PATCH 2/3] Cleanup cat: use while let instead of loop then match.

---
 src/cat/cat.rs | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/src/cat/cat.rs b/src/cat/cat.rs
index 1d8011f74..0821082b1 100644
--- a/src/cat/cat.rs
+++ b/src/cat/cat.rs
@@ -101,11 +101,9 @@ fn write_lines(files: Vec<String>, number: NumberingMode, squeeze_blank: bool,
         let mut out_buf = [0; 1024 * 64];
         let mut writer = UnsafeWriter::new(out_buf.as_mut_slice(), stdout_raw());
         let mut at_line_start = true;
-        loop {
-            let n = match reader.read(&mut in_buf) {
-                Ok(n) if n != 0 => n,
-                _ => break,
-            };
+        while let Ok(n) = reader.read(&mut in_buf) {
+            if n == 0 { break }
+
             let in_buf = &in_buf[..n];
             let mut buf_pos = range(0, n);
             loop {
@@ -173,11 +171,9 @@ fn write_bytes(files: Vec<String>, number: NumberingMode, squeeze_blank: bool,
         let mut out_buf = [0; 1024 * 64];
         let mut writer = UnsafeWriter::new(out_buf.as_mut_slice(), stdout_raw());
         let mut at_line_start = true;
-        loop {
-            let n = match reader.read(&mut in_buf) {
-                Ok(n) if n != 0 => n,
-                _ => break,
-            };
+        while let Ok(n) = reader.read(&mut in_buf) {
+            if n == 0 { break }
+
             for &byte in in_buf[..n].iter() {
                 if flush_counter.next().is_none() {
                     writer.possibly_flush();
@@ -239,14 +235,10 @@ fn write_fast(files: Vec<String>) {
     let mut in_buf = [0; 1024 * 64];
 
     for (mut reader, _) in files.iter().filter_map(|p| open(&p[])) {
-        loop {
-            match reader.read(&mut in_buf) {
-                Ok(n) if n != 0 => {
-                    // This interface is completely broken.
-                    writer.write(&in_buf[..n]).unwrap();
-                },
-                _ => break
-            }
+        while let Ok(n) = reader.read(&mut in_buf) {
+            if n == 0 { break }
+            // This interface is completely broken.
+            writer.write(&in_buf[..n]).unwrap();
         }
     }
 }

From 7647a37bf84937c41b7d263a1197ee6fb2e020ee Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Sun, 25 Jan 2015 01:21:31 -0500
Subject: [PATCH 3/3] Cleanup cat: use slicing syntax.

---
 src/cat/cat.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/cat/cat.rs b/src/cat/cat.rs
index 0821082b1..d560cf908 100644
--- a/src/cat/cat.rs
+++ b/src/cat/cat.rs
@@ -22,7 +22,7 @@ use std::io::{IoResult};
 use std::ptr::{copy_nonoverlapping_memory};
 
 pub fn uumain(args: Vec<String>) -> isize {
-    let program = args[0].as_slice();
+    let program = &args[0];
     let opts = [
         getopts::optflag("A", "show-all", "equivalent to -vET"),
         getopts::optflag("b", "number-nonblank",
@@ -48,8 +48,8 @@ pub fn uumain(args: Vec<String>) -> isize {
         println!("Usage:");
         println!("  {0} [OPTION]... [FILE]...", program);
         println!("");
-        print(getopts::usage("Concatenate FILE(s), or standard input, to \
-                             standard output.", &opts).as_slice());
+        print(&getopts::usage("Concatenate FILE(s), or standard input, to \
+                             standard output.", &opts)[]);
         println!("");
         println!("With no FILE, or when FILE is -, read standard input.");
         return 0;