Learning to Write Go
+
Jeffrey Hulten
-
Who Am I
@@ -77,131 +78,25 @@What I'm Going to Cover
Top Three Hints
--
-
- Google for "golang", not "go".
- http://lmgtfy.com/?q=golang
- -
- - Try the standard library first.
Especially "net/http"
- - Learn to love channels -
Not For You? Parting Hint...
+Google for "golang", not "go".
+ http://lmgtfy.com/?q=golang
+
The Artifact is the Thing
-
+ Simplicity
++ Rich Hickey - Creator of Clojure +
+ http://www.infoq.com/presentations/Simple-Made-Easy+
We program with constructs[...]+
but we are in a business of artifacts.
Go is a language for concurrency
Common Toolchain, Common Practices
-
-
- -
-
go clean
- go get
- go fmt
- go test
- go build
-
go clean
-
-go clean [-i] [-r] [-n] [-x] [packages]
- -
-
- _obj/
- old object directory, left from Makefiles -
- _test/
- old test directory, left from Makefiles -
- _testmain.go
- old gotest file, left from Makefiles -
- test.out
- old test log, left from Makefiles -
- build.out
- old test log, left from Makefiles -
- *.[568ao]
- object files, left from Makefiles - -
- DIR(.exe)
- from go build -
- DIR.test(.exe)
- from go test -c -
- MAINFILE(.exe)
- from go build MAINFILE.go -
- *.so
- from SWIG -
go get
- -
-
- Downloads and installs the packages named by the import paths, along with their dependencies. -
-go get [-d] [-fix] [-t] [-u] [build flags] [packages]
- go fmt
- -
-
- Reformats the packages listed to the golang standard. -
- It prints the names of the files that are modified. -
- Many editors run
go fmton save.
-
-go fmt [-n] [-x] [packages]
- go test
- -
-
- Recompiles each package along with any files with names matching "*_test.go". -
- Can contain test functions, benchmark functions, and example functions. -
- It prints a summary of the test results in the format:
-
-ok archive/tar 0.011s -FAIL archive/zip 0.022s -ok compress/gzip 0.033s -... -
-
-go test [-c] [-i] [build/test flags] [packages] [flags for test binary]
-go test ./...
-go test github.com/goraft/raft
- go build
- -
-
- Compiles the packages named by the import paths, along with their dependencies. -
- Does not install the results. -
-go build [-o output] [build flags] [packages]
-go build ./...
- go install
- -
-
- Compiles and installs the packages named by the import paths, along with their dependencies -
-go install [build flags] [packages]
-go install github.com/crosbymichael/skydock
-
Hello, Playground!
@@ -211,14 +106,11 @@
http://play.golang.org/
-
-
+
+
package main
import "fmt"
@@ -266,7 +158,7 @@ Standard Packages
External Packages
-
+
package main
import (
@@ -304,7 +196,7 @@ Packaging Gimmies and Gotchas
Private vs Public
-
+
package mypkg
func thisIsPrivate() {}
@@ -318,23 +210,31 @@ Private vs Public
Types
Golang is statically typed
-
+
var I int
var myString string = "my string"
fileReader, err := os.Open("/tmp/filename")
+http://golang.org/ref/spec#Variable_declarations
-
- Structs
-
-
-
-
+
+Structs
+
type TinyStruct struct {
IsTiny bool
}
+t1 := TinyStruct{}
+t2 := TinyStruct{true}
+t3 := TinyStruct{IsTiny: false}
+t3.IsTiny
+
+http://golang.org/ref/spec#Struct_types
+
+
+Structs
+
type MyStruct struct {
TinyStruct
A string
@@ -344,18 +244,45 @@ Structs
}
}
+var ms MyStruct
+ms = MyStruct{}
+ms.A = "one"
+ms.IsTiny = true
+
+if ms.TinyStruct.IsTiny {...}
+
+
+
+Structs
+
type OtherStruct struct {
MStruct MyStruct
OtherField string
}
+
+os := OtherStruct{MStruct : MyStruct{IsTiny: false}, OtherField : "thing"}
-
-
- Interfaces
+
+
+
+ Functions
+
+
+func FunctionName(argument string, arg1, arg2 int64) {...}
+func FunctionName(values ...int) error {...}
+func FunctionName()(namedReturn int) {...}
+var f := func() {...}
+
+
+http://golang.org/ref/spec#Function_declarations
+
+
+
+Interfaces and Methods
-
+
type Thinger interface {
DoThing() error
}
@@ -367,24 +294,19 @@ Interfaces
func (os *OtherStruct)DoThing() error {
return nil
}
+
+func ProcessThinger(t Thinger) error {
+ return t.DoThing()
+}
+http://golang.org/ref/spec#Interface_types
+http://golang.org/ref/spec#Method_declarations
Empty Interface is an Any Type
-
- Functions
-
-
-func FunctionName(argument string, arg1, arg2 int63) {...}
-func FunctionName(values ...int) error {...}
-func FunctionName()(namedReturn int) {...}
-var f := func() {...}
-
-
-
@@ -411,7 +333,7 @@ RandReader Type
Struct with no public elements