Go

Channels, errors, context and the Go runtime.

The course

Open the course

Start at 01. The first lesson names the types. The next one builds an object. Each sample is on the page.

  1. Skill

    Basics

    The types, explained, then an object you can name and call.

    1. 01 Go from zero: a name has a type Start here

      A Go name has a type. name is a string, cents is an int, and ready is a bool. The program prints latte $4.50 ready.

      Adds The types this course uses

      2 min read

    2. 02 Go from zero: a struct is the object

      A struct groups named fields, and a method is a function on that struct. Item holds a drink and a price in cents, and Label prints latte $4.50.

      Adds An object you can name and call

      Builds on 12 min read

  2. Practice

    Tips

    A rule that prevents a bug, then a program that uses the object.

    1. 03 Go from zero: zero is a real value

      A var with no value is not empty of meaning. A blank order has an empty name and 0 cents. The program prints "" $0.00.

      Adds A tip that prevents a bug

      Builds on 1 through 22 min read

    2. 04 Go from zero: make the map before you write

      A map has to be made before a write. map[string]int{} makes a menu. The program stores 450 under latte and prints 450.

      Adds A program that uses the object

      Builds on 1 through 32 min read

  3. Further

    A whole program

    One more idea, then a program that puts the pieces together.

    1. 05 Go from zero: a method can change the struct

      A method with a pointer receiver changes the struct the caller holds. AddTip adds 20 percent to a $4.50 bill, and the program prints $5.40.

      Adds A program that puts the pieces together

      Builds on 1 through 42 min read

    2. 06 Go from zero: an interface is a method list

      An interface names the methods a function needs. Labeller asks for Label, Item has Label, and show prints latte $4.50.

      Adds A program that puts the pieces together

      Builds on 1 through 52 min read

GoByte Skills: Go track, 3 lessons. Channels, error wrapping and context: how Go makes concurrency and failure explicit.

Open the Go track

Articles

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  • Context: cancel the parent, the children hear it

    GoByte Skills #3: One cancel() at the root closes Done on every context below it, and closing a channel wakes every waiter at once. Context is a tree, not a kill switch. Also: why a dropped stop() leaks.

    GoPiereOct 6, 20263 min read

  • errors.Is: wrap it, keep the cause

    GoByte Skills #2: %v prints the exact same message and quietly drops the chain. %w keeps it, and errors.Is walks it link by link, so the cause survives every layer of context.

    GoPiereOct 6, 20262 min read

  • Go channels: the queue that says no

    GoByte Skills #1: A buffered channel is a bounded queue. When it is full, the send parks until there is room, so the slow consumer sets the pace. Backpressure in one argument to make(), plus the exact order a real run prints.

    GoPiereOct 6, 20263 min read