diff --git a/examples/line-filters/line-filters.go b/examples/line-filters/line-filters.go index ba3af22..25b13da 100644 --- a/examples/line-filters/line-filters.go +++ b/examples/line-filters/line-filters.go @@ -22,16 +22,16 @@ func main() { // advances the scanner to the next token; which is // the next line in the default scanner. scanner := bufio.NewScanner(os.Stdin) - + for scanner.Scan() { // `Text` returns the current token, here the next line, - // from the input. + // from the input. ucl := strings.ToUpper(scanner.Text()) - + // Write out the uppercased line. fmt.Println(ucl) } - + // Check for errors during `Scan`. End of file is // expected and not reported by `Scan` as an error. if err := scanner.Err(); err != nil { diff --git a/examples/line-filters/line-filters.hash b/examples/line-filters/line-filters.hash index c5c6dc4..d36a15d 100644 --- a/examples/line-filters/line-filters.hash +++ b/examples/line-filters/line-filters.hash @@ -1,2 +1,2 @@ -fe6d70a3115bd0974aa6f3f8444bb539d17fc027 -OSS71nSpkV +87f4a67edf741979f8ff6da85947aa177547f9ef +mpYwOHj2ma diff --git a/public/line-filters b/public/line-filters index b8ddf7b..b06e5e1 100644 --- a/public/line-filters +++ b/public/line-filters @@ -45,7 +45,7 @@ pattern to write your own Go line filters.

- + 
package main
@@ -61,7 +61,6 @@ pattern to write your own Go line filters.

import (
     "bufio"
     "fmt"
-    "io"
     "os"
     "strings"
 )
@@ -85,14 +84,14 @@ pattern to write your own Go line filters.

         
           
             
Wrapping the unbuffered os.Stdin with a buffered
-reader gives us a convenient ReadString method
-that we’ll use to read input line-by-line.

+scanner gives us a convenient Scan method that
+advances the scanner to the next token; which is
+the next line in the default scanner.

 
           
           
 	        
-            
    rdr := bufio.NewReader(os.Stdin)
-    out := os.Stdout
+            
    scanner := bufio.NewScanner(os.Stdin)
 

 
           
@@ -100,16 +99,13 @@ that we’ll use to read input line-by-line.

         
         
           
-            
ReadString returns the next string from the
-input up to the given separator byte. We give the
-newline byte '\n' as our separator so we’ll get
-successive input lines.

+            
Text returns the current token, here the next line,
+from the input.

 
           
           
 	        
-            
    for {
-        switch line, err := rdr.ReadString('\n'); err {
+            
    for scanner.Scan() {
 

 
           
@@ -117,19 +113,11 @@ successive input lines.

         
         
           
-            
If the read succeeded (the read err is nil),
-write out out the uppercased line. Check for an
-error on this write as we do on the read.

-
+            
           
           
 	        
-            
        case nil:
-            ucl := strings.ToUpper(line)
-            if _, err = out.WriteString(ucl); err != nil {
-                fmt.Fprintln(os.Stderr, "error:", err)
-                os.Exit(1)
-            }
+            
        ucl := strings.ToUpper(scanner.Text())
 

 
           
@@ -137,14 +125,13 @@ error on this write as we do on the read.

         
         
           
-            
The EOF error is expected when we reach the
-end of input, so exit gracefully in that case.

+            
Write out the uppercased line.

 
           
           
 	        
-            
        case io.EOF:
-            os.Exit(0)
+            
        fmt.Println(ucl)
+    }
 

 
           
@@ -152,16 +139,15 @@ end of input, so exit gracefully in that case.

         
         
           
-            
Otherwise there’s a problem; print the
-error and exit with non-zero status.

+            
Check for errors during Scan. End of file is
+expected and not reported by Scan as an error.

 
           
           
 	        
-            
        default:
-            fmt.Fprintln(os.Stderr, "error:", err)
-            os.Exit(1)
-        }
+            
    if err := scanner.Err(); err != nil {
+        fmt.Fprintln(os.Stderr, "error:", err)
+        os.Exit(1)
     }
 }