# learning

stuff we learned along the way

## 2021-12-28

Stuff i learned about go


- `:=` short assignment, infers type: `x := 4`. vs "long" assignment: `var x int; x = 4`
- expressive ifs: declare, assign, evaluate

    ```
    if x := isBar(); x > 10 {
      println("big number")
    } else {
      println("it's kind of small")
    }
    ```

- `defer` wrapup (e.g. `conn.Close()`)
- data structures are array (fixed), slice (variable), and channel
- mulitiple returns. common convention:

    ```
    foo, err := bar()
    if err != nil {
      return err
    }
    ```
- pointers 😬
- use `make` to make arrays, slices, channels
- `for` is the only loop.
- structs and interfaces. here's a pair type:

    ```
    type pair struct {
      x, y int
    }
    ```

    and here's a toString interface:

    ```
    type Stringer interface {
      toString() string
    }
    ```

    and here's adding a method to a struct to implement the interface:

    ```
    func(p pair) toString() string {
      return fmt.Sprintf("(%d, %d)", p.x, p.y)
    }
    ```

    and here's using the compiler to check the interface:

    ```
    var p Stringer = pair{3, 4}
    ```

resources

- https://learnxinyminutes.com/docs/go/
- https://www.youtube.com/watch?v=Eb1Q98PmyLQ
- https://www.youtube.com/watch?v=oyKrI8e1-9U&t
- https://pkg.go.dev/net/http
- https://github.com/josa42/coc-go