Synchronous concurrency: Difference between revisions

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@@ Line 963: / Line 963: @@
 import (
+	"bufio"
-    "fmt"
+	"fmt"
-    "bufio"
-    "io"
+	"io"
-    "os"
+	"os"
 )
 // main, one of two goroutines used, will function as the "reading unit"
 func main() {
-    // get file open first
+	// get file open first
-    f, err := os.Open("input.txt")
+	f, err := os.Open("input.txt")
-    if err != nil {
+	if err != nil {
-        fmt.Println(err)
+		fmt.Println(err)
-        return
+		return
+	}
-    }
-    defer f.Close()
+	defer f.Close()
-    lr := bufio.NewReader(f)
+	lr := bufio.NewReader(f)
-    // that went ok, now create communication channels,
+	// that went ok, now create communication channels,
-    // and start second goroutine as the "printing unit"
+	// and start second goroutine as the "printing unit"
-    lines := make(chan string)
+	lines := make(chan string)
-    count := make(chan int)
+	count := make(chan int)
-    go printer(lines, count)
+	go printer(lines, count)
-    for {
+	for {
-        line, prefix, err := lr.ReadLine()
+		switch line, err := lr.ReadString('\n'); err {
+		case nil:
-        switch {
+			lines <- line
-        case err == io.EOF:
+			continue
-        case err != nil:
+		case io.EOF:
-            fmt.Println(err)
+		default:
-        case prefix:
-            fmt.Println("unexpected long line")
+			fmt.Println(err)
+		}
-        default:
+		break
-            lines <- string(line)
+	}
-            continue
-        }
+	// this represents the request for the printer to send the count
-        break
+	close(lines)
-    }
-    // this represents the request for the printer to send the count
+	// wait for the count from the printer, then print it, then exit
+	fmt.Println("Number of lines:", <-count)
-    close(lines)
-    // wait for the count from the printer, then print it, then exit
-    fmt.Println("Number of lines:", <-count)
 }
 func printer(in <-chan string, count chan<- int) {
-    c := 0
+	c := 0
-    // loop as long as in channel stays open
+	// loop as long as in channel stays open
-    for s := range in {
+	for s := range in {
-        fmt.Println(s)
+		fmt.Print(s)
-        c++
+		c++
+	}
-    }
-    // make count available on count channel, then return (terminate goroutine)
+	// make count available on count channel, then return (terminate goroutine)
-    count <- c
+	count <- c
 }</lang>