简单的golang程序无法运行

Question

Here is a simple golang script T1.go:

package main

import "fmt"

func main() {
    fmt.Println("Hello world")
}

run it with go run T1.go, I get:

T1.go:1:15: expected ';', found 'import'

If I added ; to line end, the program is okay to run:

package main;

import "fmt";

func main() {
    fmt.Println("Hello world")
}

But isn't the semicolon redundant of line ending in golang?

PS: I am on 64bit window 7, the golang version is devel +f4d1cb8d9a91 or 1.2rc1. The error code runs perfect on http://play.golang.org/

Updates I've used dos2unix to convert the source code to unix line ending, but it doesn't change anything

Notes My go is installed in C:\go directory and the C:\go\bin is added into the %PATH% environment variable; The source code T1.go is put inside the C:\t\go directory, which is different from the go installation directory. Not sure if this configuration contribute to the issue.

Answer 1

Your Hex dump shows that you are using Carriage Return characters (U+000D) instead of LineFeeds (U+000A) in the T1.go file. Using only CR as End-of-line is an old Mac way of doing it.

The specification states that a new line is a single line feed character. Since this is not found, the parser assumes it is all written on the same line. In such a case, the compiler requires that you actually type out the semi-colons.

Solution

Change your CR to LF and it should work.

If you use Notepad++, you can do this conversion in the menu Edit - EOL Conversion - Unix/OSX Format.

go fmt does not convert CR to LF, while it does convert CRLF to LF.
The same goes for dos2unix. In your case, it should work with mac2unix.