Merge pull request #1 from krasin/master

Update gcd.go to Go 1. Make the code more idiomatic

1 files changed, 31 insertions, 40 deletions

diff --git a/gcd.go b/gcd.go
index 04f772d..96f601b 100644
--- a/gcd.go
+++ b/gcd.go
@@ -5,10 +5,11 @@
  # gccgo gcd.go -o gcd-go
  # ./gcd-go 11 22 33 44 121
 
- With Google Go (6g for amd64, 8g for x86, http://golang.org/cmd/):
- # 6g -o gcd-go.o  gcd.go
- # 6l -o gcd-go-6g gcd-go.o
- # ./gcd-go-6g 11 22 33 44 121
+ With Google Go (http://golang.org/):
+ # go run gcd.go 11 22 33 44 121
+ # or, if you want to play with the binary
+ # go build -o gcd-go gcd.go
+ # ./gcd-go 11 22 33 44 121
 
  GCC makes dynamically linked binary,
  but Google Go - statically linked
@@ -17,45 +18,35 @@
 
 package main
 
-// Both Google Go and GCC issue an error "imported and not used",
-// if imported and not used :-)
-import "fmt"
-import "flag"
-import "strconv"
-
-func gcd2 (a, b uint) uint {
-    if b == 0 {
-        return a
-    }
-    /* 6g issues an error "function ends without a return statement",
-       if we use if ... {... return} else {... return}.
-       But GCC doesn't.
-    */
-    return gcd2(b, a % b)
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+func gcd2(a, b uint64) uint64 {
+	if b == 0 {
+		return a
+	}
+	return gcd2(b, a%b)
 }
 
-func gcdn (ns []uint) uint {
-    var r uint // zero by default
-    for i := range ns {
-        r = gcd2(r, ns[i])
-    }
-    return r
+func gcdn(ns []uint64) (r uint64) {
+	for _, v := range ns {
+		r = gcd2(r, v)
+	}
+	return
 }
 
 func main() {
-    flag.Parse() // without this 6g will give flag.NArg() = 0 next (WTF?)
-    n := flag.NArg()
-    if n > 0 {
-        ns := make([]uint, n) // We have garbage collector!
-
-        // Or: for i := range ns, since range of ns is equal to flag.NArg()
-        for i := 0; i < n; i++ {
-            // Drop the second return value (error code):
-            ns[i], _ = strconv.Atoui(flag.Arg(i))
-        }
-
-        g  := gcdn(ns)
-        fmt.Printf("%v\n", g)
-    }
+	if len(os.Args) == 1 {
+		return
+	}
+	var ns []uint64 // We have garbage collector!
+	for _, arg := range os.Args[1:] {
+		// Drop the second return value (error code):
+		v, _ := strconv.ParseUint(arg, 0, 64)
+		ns = append(ns, v)
+	}
+	fmt.Printf("%v\n", gcdn(ns))
 }
-