Thoughts of a rustacean learning Go

▲ Klaus Post 3103 days ago ▼

Good post. Shows very well which aspects of Go is easy to pick up, and which isn't.

The code examples naturally shows an how a newcomer would approach this.

I have no idea where the author picked up "A major recurring point is that Go seems to advocate runtime over compile time checking", which couldn't be more false IMO.

For fun, I did a quick re-write of how it typically would look:


type Drawer interface {
  DrawTo(image.Image)
}

type Line struct {
    color Color
    a Point
    b Point
}

func (d  Line) DrawTo(bg image.Image)  {}

type Triangle struct {
    color Color
    fill Color
    a Point
    b Point
    c Point
}
func (d  Triangle) DrawTo(bg image.Image)  {}

type Fill struct {
    color Color
}

func (d  Fill) DrawTo(bg image.Image)  {}

func paintingLoop(img image.Image, ch chan Drawer) {
    // shorthand for a loop over receiving over
    // a channel
    for msg := range ch {
         msg.DrawTo(img)
    }
}
 
func drawThingy(ch chan Drawer) {
    ch <- Line {color: Red, a: Point{x:0, y: 0]}, b: Point{x: 1, y: 1}}
    ch <- Background{color: Blue}
}
 
func main() {
    // do some setup
    ch := make(chan Drawer, 100)

  // Create out destination image 
   var img = image.NewNRGBA(image.Rectangle(100,100))

    // Creates a goroutine which will handle the
    // event loop
    go func() {
        // create the window, etc
        paintingLoop(ch, img)
    }()
 
    drawThingy(ch)

    // Close when done.
    close(ch)
    // TODO: Add a channel to indicate image is done
}

▲ Klaus Post 3103 days ago ▼

Gist, since this doesn't really handle inline code ;)

https://gist.github.com/klauspost/e6105a857de22a028171

▲ kenny 3103 days ago ▼

Hi Klaus, I need to sort the editor out, but you can use pre and code tags to display code, I've edited your comment above to do this. You can also use anchor tags to put links in (again will have a friendlier interface soon using contenteditable).

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