commit 194ca9b7a90365dd1f8d53ad3682314344d4c347 Author: V Date: Sat Aug 30 13:55:18 2025 +0100 Initial commit - learning the basics diff --git a/api_gin/go.mod b/api_gin/go.mod new file mode 100644 index 0000000..c0cb648 --- /dev/null +++ b/api_gin/go.mod @@ -0,0 +1,33 @@ +module learning.local/api_gin + +go 1.24.5 + +require ( + github.com/bytedance/sonic v1.13.3 // indirect + github.com/bytedance/sonic/loader v0.3.0 // indirect + github.com/cloudwego/base64x v0.1.5 // indirect + github.com/cloudwego/iasm v0.2.0 // indirect + github.com/gabriel-vasile/mimetype v1.4.9 // indirect + github.com/gin-contrib/sse v1.1.0 // indirect + github.com/gin-gonic/gin v1.10.1 // indirect + github.com/go-playground/locales v0.14.1 // indirect + github.com/go-playground/universal-translator v0.18.1 // indirect + github.com/go-playground/validator/v10 v10.27.0 // indirect + github.com/goccy/go-json v0.10.5 // indirect + github.com/json-iterator/go v1.1.12 // indirect + github.com/klauspost/cpuid/v2 v2.3.0 // indirect + github.com/leodido/go-urn v1.4.0 // indirect + github.com/mattn/go-isatty v0.0.20 // indirect + github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect + github.com/modern-go/reflect2 v1.0.2 // indirect + github.com/pelletier/go-toml/v2 v2.2.4 // indirect + github.com/twitchyliquid64/golang-asm v0.15.1 // indirect + github.com/ugorji/go/codec v1.3.0 // indirect + golang.org/x/arch v0.19.0 // indirect + golang.org/x/crypto v0.40.0 // indirect + golang.org/x/net v0.42.0 // indirect + golang.org/x/sys v0.34.0 // indirect + golang.org/x/text v0.27.0 // indirect + google.golang.org/protobuf v1.36.6 // indirect + gopkg.in/yaml.v3 v3.0.1 // indirect +) diff --git a/api_gin/go.sum b/api_gin/go.sum new file mode 100644 index 0000000..c74a8d0 --- /dev/null +++ b/api_gin/go.sum @@ -0,0 +1,75 @@ +github.com/bytedance/sonic v1.13.3 h1:MS8gmaH16Gtirygw7jV91pDCN33NyMrPbN7qiYhEsF0= +github.com/bytedance/sonic v1.13.3/go.mod h1:o68xyaF9u2gvVBuGHPlUVCy+ZfmNNO5ETf1+KgkJhz4= +github.com/bytedance/sonic/loader v0.1.1/go.mod h1:ncP89zfokxS5LZrJxl5z0UJcsk4M4yY2JpfqGeCtNLU= +github.com/bytedance/sonic/loader v0.3.0 h1:dskwH8edlzNMctoruo8FPTJDF3vLtDT0sXZwvZJyqeA= +github.com/bytedance/sonic/loader v0.3.0/go.mod h1:N8A3vUdtUebEY2/VQC0MyhYeKUFosQU6FxH2JmUe6VI= +github.com/cloudwego/base64x v0.1.5 h1:XPciSp1xaq2VCSt6lF0phncD4koWyULpl5bUxbfCyP4= +github.com/cloudwego/base64x v0.1.5/go.mod h1:0zlkT4Wn5C6NdauXdJRhSKRlJvmclQ1hhJgA0rcu/8w= +github.com/cloudwego/iasm v0.2.0 h1:1KNIy1I1H9hNNFEEH3DVnI4UujN+1zjpuk6gwHLTssg= +github.com/cloudwego/iasm v0.2.0/go.mod h1:8rXZaNYT2n95jn+zTI1sDr+IgcD2GVs0nlbbQPiEFhY= +github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/gabriel-vasile/mimetype v1.4.9 h1:5k+WDwEsD9eTLL8Tz3L0VnmVh9QxGjRmjBvAG7U/oYY= +github.com/gabriel-vasile/mimetype v1.4.9/go.mod h1:WnSQhFKJuBlRyLiKohA/2DtIlPFAbguNaG7QCHcyGok= +github.com/gin-contrib/sse v1.1.0 h1:n0w2GMuUpWDVp7qSpvze6fAu9iRxJY4Hmj6AmBOU05w= +github.com/gin-contrib/sse v1.1.0/go.mod h1:hxRZ5gVpWMT7Z0B0gSNYqqsSCNIJMjzvm6fqCz9vjwM= +github.com/gin-gonic/gin v1.10.1 h1:T0ujvqyCSqRopADpgPgiTT63DUQVSfojyME59Ei63pQ= +github.com/gin-gonic/gin v1.10.1/go.mod h1:4PMNQiOhvDRa013RKVbsiNwoyezlm2rm0uX/T7kzp5Y= +github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA= +github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY= +github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY= +github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY= +github.com/go-playground/validator/v10 v10.27.0 h1:w8+XrWVMhGkxOaaowyKH35gFydVHOvC0/uWoy2Fzwn4= +github.com/go-playground/validator/v10 v10.27.0/go.mod h1:I5QpIEbmr8On7W0TktmJAumgzX4CA1XNl4ZmDuVHKKo= +github.com/goccy/go-json v0.10.5 h1:Fq85nIqj+gXn/S5ahsiTlK3TmC85qgirsdTP/+DeaC4= +github.com/goccy/go-json v0.10.5/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M= +github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg= +github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM= +github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo= +github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg= +github.com/klauspost/cpuid/v2 v2.3.0 h1:S4CRMLnYUhGeDFDqkGriYKdfoFlDnMtqTiI/sFzhA9Y= +github.com/klauspost/cpuid/v2 v2.3.0/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0= +github.com/knz/go-libedit v1.10.1/go.mod h1:MZTVkCWyz0oBc7JOWP3wNAzd002ZbM/5hgShxwh4x8M= +github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ= +github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI= +github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY= +github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y= +github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q= +github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg= +github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q= +github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M= +github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk= +github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4= +github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY= +github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= +github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME= +github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw= +github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo= +github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI= +github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg= +github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg= +github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU= +github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4= +github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS4MhqMhdFk5YI= +github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08= +github.com/ugorji/go/codec v1.3.0 h1:Qd2W2sQawAfG8XSvzwhBeoGq71zXOC/Q1E9y/wUcsUA= +github.com/ugorji/go/codec v1.3.0/go.mod h1:pRBVtBSKl77K30Bv8R2P+cLSGaTtex6fsA2Wjqmfxj4= +golang.org/x/arch v0.19.0 h1:LmbDQUodHThXE+htjrnmVD73M//D9GTH6wFZjyDkjyU= +golang.org/x/arch v0.19.0/go.mod h1:bdwinDaKcfZUGpH09BB7ZmOfhalA8lQdzl62l8gGWsk= +golang.org/x/crypto v0.40.0 h1:r4x+VvoG5Fm+eJcxMaY8CQM7Lb0l1lsmjGBQ6s8BfKM= +golang.org/x/crypto v0.40.0/go.mod h1:Qr1vMER5WyS2dfPHAlsOj01wgLbsyWtFn/aY+5+ZdxY= +golang.org/x/net v0.42.0 h1:jzkYrhi3YQWD6MLBJcsklgQsoAcw89EcZbJw8Z614hs= +golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8= +golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= +golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA= +golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k= +golang.org/x/text v0.27.0 h1:4fGWRpyh641NLlecmyl4LOe6yDdfaYNrGb2zdfo4JV4= +golang.org/x/text v0.27.0/go.mod h1:1D28KMCvyooCX9hBiosv5Tz/+YLxj0j7XhWjpSUF7CU= +google.golang.org/protobuf v1.36.6 h1:z1NpPI8ku2WgiWnf+t9wTPsn6eP1L7ksHUlkfLvd9xY= +google.golang.org/protobuf v1.36.6/go.mod h1:jduwjTPXsFjZGTmRluh+L6NjiWu7pchiJ2/5YcXBHnY= +gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= +gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= +gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA= +gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= +nullprogram.com/x/optparse v1.0.0/go.mod h1:KdyPE+Igbe0jQUrVfMqDMeJQIJZEuyV7pjYmp6pbG50= +rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4= diff --git a/api_gin/main.go b/api_gin/main.go new file mode 100644 index 0000000..eebc26c --- /dev/null +++ b/api_gin/main.go @@ -0,0 +1,42 @@ +package main + +import ( + "github.com/gin-gonic/gin" + "net/http" + "fmt" + "encoding/json" +) + +func main() { + router := gin.Default() + router.GET("/", func(c *gin.Context) { + c.JSON(http.StatusOK, gin.H{ + "message": "Hiya!", + }) + }) + router.GET("/ping", func(c *gin.Context) { + c.JSON(http.StatusOK, gin.H{ + "message": "pong", + }) + }) + router.GET("/pokemon/:name", func(c *gin.Context) { + name := c.Param("name") + url := fmt.Sprintf("https://pokeapi.co/api/v2/pokemon/%s", name) + res, err := http.Get(url) + if err != nil { + fmt.Printf("Could not retrieve info for Pokemon %s!", name) + } + + var result map[string]any + decoder := json.NewDecoder(res.Body) + defer res.Body.Close() + if err := decoder.Decode(&result); err != nil { + fmt.Printf("Could not read response body!") + } + c.JSON(http.StatusOK, gin.H{ + "message": "success", + "pokemon_info": result, + }) + }) + router.Run() +} diff --git a/hello/go.mod b/hello/go.mod new file mode 100644 index 0000000..a08bdfc --- /dev/null +++ b/hello/go.mod @@ -0,0 +1,7 @@ +module learning.local/hello + +go 1.24.5 + +replace learning.local/using_modules => ../using_modules + +require learning.local/using_modules v0.0.0-00010101000000-000000000000 diff --git a/hello/hello.go b/hello/hello.go new file mode 100644 index 0000000..7cf8c06 --- /dev/null +++ b/hello/hello.go @@ -0,0 +1,28 @@ +package main + +import ( + "fmt" + "log" + + "learning.local/using_modules" +) + +func main () { + // Set properties of the predefined Logger, including + // the log entry prefix and a flag to disable printing + // the time, source fiile, and line number. + log.SetPrefix("using_modules: ") + log.SetFlags(0) + + // A slice of names + names := []string{"Gladys", "Yoda", "Darth Vader"} + + // Request greeting messages for the names + messages, err := using_modules.Hellos(names) + if err != nil { + log.Fatal(err) + } + // If no error was returned, print the returned map of + // messages to the console + fmt.Println(messages) +} diff --git a/hello/using_modules.go b/hello/using_modules.go new file mode 100644 index 0000000..9841c0f --- /dev/null +++ b/hello/using_modules.go @@ -0,0 +1,35 @@ +package using_modules + +import ( + "fmt" + "errors" + "math/rand" +) + +// Hello returns a greeting for the named person +func Hello(name string) (string, error) { + // If no name was given, return an error with a message + if name == "" { + return "", errors.New("Empty name!") + } + + message := fmt.Sprintf(randomFormat(), name) + return message, nil +} + + +// randomFormat returns one of a set of greeting messages. The returned +// message is selected at random. + +func randomFormat() string { + // A slice of message formats + formats := []string{ + "Hi, %v. Welcome!", + "Great to see you, %v", + "Hail, %v! Well met!", + } + + // Return a randomly selected message format by specifying + // a random index for the slice of formats. + return formats[rand.Intn(len(formats))] +} diff --git a/tour_of_go/l1/go.mod b/tour_of_go/l1/go.mod new file mode 100644 index 0000000..0e58373 --- /dev/null +++ b/tour_of_go/l1/go.mod @@ -0,0 +1,10 @@ +module learning/tour + +go 1.24.5 + +require rsc.io/quote v1.5.2 + +require ( + golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c // indirect + rsc.io/sampler v1.3.0 // indirect +) diff --git a/tour_of_go/l1/go.sum b/tour_of_go/l1/go.sum new file mode 100644 index 0000000..4a8bcd7 --- /dev/null +++ b/tour_of_go/l1/go.sum @@ -0,0 +1,6 @@ +golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8= +golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= +rsc.io/quote v1.5.2 h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y= +rsc.io/quote v1.5.2/go.mod h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe+TKr0= +rsc.io/sampler v1.3.0 h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4= +rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA= diff --git a/tour_of_go/l1/hello.go b/tour_of_go/l1/hello.go new file mode 100644 index 0000000..fb6bb60 --- /dev/null +++ b/tour_of_go/l1/hello.go @@ -0,0 +1,10 @@ +package main + +import "fmt" +import "rsc.io/quote" + +func main() { + fmt.Println("Hello Go!") + fmt.Println(quote.Go()) +} + diff --git a/tour_of_go/l2/functions.go b/tour_of_go/l2/functions.go new file mode 100644 index 0000000..5a43539 --- /dev/null +++ b/tour_of_go/l2/functions.go @@ -0,0 +1,64 @@ +package main + +import ( + "fmt" + "math/cmplx" +) + +var c, java, python bool +var n, m int = 1, 2 +var ( + ToBe bool = false + MaxInt uint64 = 1<<64 - 1 + z complex128 = cmplx.Sqrt(-5 + 12i) +) + +func add(x, y int) int { + return x + y +} + +func swap (x, y string) (string, string) { + return y, x +} + +func split(sum int) (x, y int) { + x = sum * 4 / 9 + y = sum - x + return +} + +func main() { + fmt.Println(add(42,13)) + x := [3]int{2,1,1} + fmt.Println(x) + + a, b := swap("hello", "go") + fmt.Println(a, b) + + fmt.Println(split(17)) + + var i int + fmt.Println(i, c, python, java) + + c, java, python := true, true, "no!" + k := 3 + fmt.Println(k, n, m, c, python, java) + + fmt.Printf("Type: %T Value: %v\n", ToBe, ToBe) + fmt.Printf("Type: %T Value: %v\n", MaxInt, MaxInt) + fmt.Printf("Type: %T Value: %v\n", z, z) + + g := 42 + f := float64(g) + u := uint(f) + fmt.Println(g, f, u) + + const Pi = 3.14 + const World = "世界" + const Truth = true + + fmt.Println("Hello", World) + fmt.Println("Happy", Pi, "Day") + fmt.Println("Go rules?", Truth) +} + diff --git a/tour_of_go/l2/packages.go b/tour_of_go/l2/packages.go new file mode 100644 index 0000000..7924d74 --- /dev/null +++ b/tour_of_go/l2/packages.go @@ -0,0 +1,12 @@ +package main + +import ( + "fmt" + "math/rand" + "math" +) + +func main() { + fmt.Println("My favorite number is", rand.Intn(10)) + fmt.Println(math.Pi) +} diff --git "a/tour_of_go/l3/\\" "b/tour_of_go/l3/\\" new file mode 100644 index 0000000..b5f86b4 --- /dev/null +++ "b/tour_of_go/l3/\\" @@ -0,0 +1,13 @@ +package main + +import ( + "fmt" +) + +func Sqrt(x float64) float64 { + +} + +func main() { + fmt.Println(Sqrt(2)) +} diff --git a/tour_of_go/l3/conditionals.go b/tour_of_go/l3/conditionals.go new file mode 100644 index 0000000..e9cde0c --- /dev/null +++ b/tour_of_go/l3/conditionals.go @@ -0,0 +1,22 @@ +package main + +import ( + "fmt" + "math" +) + +func pow(x, n, lim float64) float64 { + if v := math.Pow(x, n); v < lim { + return v + } else { + fmt.Printf("%g >= %g\n", v, lim) + } + return lim +} + +func main() { + fmt.Println( + pow(3, 2, 10), + pow(3, 3, 20), + ) +} diff --git a/tour_of_go/l3/ex1.go b/tour_of_go/l3/ex1.go new file mode 100644 index 0000000..93897d5 --- /dev/null +++ b/tour_of_go/l3/ex1.go @@ -0,0 +1,32 @@ +package main + +import ( + "fmt" +) + +func Sqrt(x float64) float64 { + precision := 0.00001 + old_z := 0.0 + z := x + iter := 0 + for (z - old_z) > precision { + iter += 1 + old_z := z + z -= (z*z - x) / (2*z) + if old_z - z < 0 { + if ((old_z - z) * -1) < precision { + fmt.Println("Required precision has been reached after", iter, "iterations! Square root of", x , "is", z) + return z + } + } else if (old_z - z) < precision { + fmt.Println("Required precision has been reached after", iter, "iterations! Square root of", x , "is", z) + return z + } + } + return z +} + +func main() { + fmt.Println(Sqrt(2)) + fmt.Println(Sqrt(29)) +} diff --git a/tour_of_go/l3/loops.go b/tour_of_go/l3/loops.go new file mode 100644 index 0000000..81c4bbe --- /dev/null +++ b/tour_of_go/l3/loops.go @@ -0,0 +1,29 @@ +package main + +import ( + "fmt" + "math" +) + +func sqrt(x float64) string { + if x < 0 { + return sqrt(-x) + "i" + } + return fmt.Sprint(math.Sqrt(x)) +} + +func main() { + sum := 0 + for i := 0; i < 10; i++ { + sum += 1 + } + fmt.Println(sum) + + sum_2 := 1 + for sum_2 < 1000 { + sum_2 += sum_2 + } + fmt.Println(sum_2) + + fmt.Println(sqrt(2), sqrt(-4)) +} diff --git a/tour_of_go/l3/switch.go b/tour_of_go/l3/switch.go new file mode 100644 index 0000000..02e8d4b --- /dev/null +++ b/tour_of_go/l3/switch.go @@ -0,0 +1,55 @@ +package main + +import ( + "fmt" + "time" + "runtime" +) + +func letsDefer(text string) { + defer fmt.Println(text) + fmt.Print("I have deferred: ") +} + +func main() { + fmt.Print("Go runs on ") + switch os := runtime.GOOS; os { + case "darwin": + fmt.Println("macOS.") + case "linux": + fmt.Println("Linux.") + default: + fmt.Printf("%s.\n", os) + } + + fmt.Println("When's Saturday?") + today := time.Now().Weekday() + switch time.Saturday { + case today + 0: + fmt.Println("Today.") + case today + 1: + fmt.Println("Tomorrow.") + case today + 2: + fmt.Println("In two days.") + default: + fmt.Println("Too far away.") + } + + t := time.Now() + switch { + case t.Hour() < 12: + fmt.Println("Good morning!") + case t.Hour() < 17: + fmt.Println("Good afternoon") + default: + fmt.Println("Good evening.") + } + + letsDefer("Some stuff") + + fmt.Println("Counting...") + for i:=0; i<10; i++ { + defer fmt.Println(i) + } + fmt.Println("Done!") +} diff --git a/tour_of_go/l4/2 b/tour_of_go/l4/2 new file mode 100644 index 0000000..fda8946 --- /dev/null +++ b/tour_of_go/l4/2 @@ -0,0 +1,39 @@ +package main + +import "fmt" + +func main() { + var aa [2]string + + aa[0] = "Hello" + aa[1] = "World" + fmt.Println(aa[0], aa[1]) + fmt.Println(aa) + + primes := [6]int{2, 3, 5, 7, 11, 13} + fmt.Println(primes) + + var s []int = primes[1:4] + fmt.Printf("The primes are %d and the slice is %d", primes, s) + + // Slices are references to array sections + // Changing elements in a slice results in changes to the array + // So other slices referencing the same array section will also be changed + + names := [4]string{ + "John", + "Paul", + "George", + "Ringo", + } + fmt.Println(names) + + a := names[0:2] + b := names[1:3] + fmt.Println(a, b) + + // Now make some changes + b[0] = "XXX" + fmt.Println(a, b) + fmt.Println(names) +} diff --git a/tour_of_go/l4/append.go b/tour_of_go/l4/append.go new file mode 100644 index 0000000..ea292ed --- /dev/null +++ b/tour_of_go/l4/append.go @@ -0,0 +1,23 @@ +package main + +import "fmt" + +func printSlice(s []int) { + fmt.Printf("len=%d cap=%d %v\n", len(s), cap(s), s) +} +func main() { + var s []int + printSlice(s) + + s = append(s, 0) + printSlice(s) + + s = append(s, 1) + printSlice(s) + + s = append(s, 2, 3, 4) + printSlice(s) + + s = append(s, 56) + printSlice(s) +} diff --git a/tour_of_go/l4/arrays.go b/tour_of_go/l4/arrays.go new file mode 100644 index 0000000..cc4eb73 --- /dev/null +++ b/tour_of_go/l4/arrays.go @@ -0,0 +1,72 @@ +package main + +import "fmt" + +func main() { + var aa [2]string + + aa[0] = "Hello" + aa[1] = "World" + fmt.Println(aa[0], aa[1]) + fmt.Println(aa) + + primes := [6]int{2, 3, 5, 7, 11, 13} + fmt.Println(primes) + + var s []int = primes[1:4] + fmt.Printf("The primes are %d and the slice is %d", primes, s) + + // Slices are references to array sections + // Changing elements in a slice results in changes to the array + // So other slices referencing the same array section will also be changed + + names := [4]string{ + "John", + "Paul", + "George", + "Ringo", + } + fmt.Println(names) + + a := names[0:2] + b := names[1:3] + fmt.Println(a, b) + + // Now make some changes + b[0] = "XXX" + fmt.Println(a, b) + fmt.Println(names) + + // Slice literals - like array literals, but without the length + q := []int{2, 3, 5, 7, 11, 13} + fmt.Println(q) + + r := []bool{true, false, true, true, false, true} + fmt.Println(r) + + sx := []struct { + i int + b bool + }{ + {2, true}, + {3, false}, + {5, true}, + {7, true}, + {11, false}, + {13, true}, + } + fmt.Println(sx) + + // Slice defaults + + ss := []int{2, 3, 5, 7, 11, 13} + + ss = ss[1: 4] + fmt.Println(ss) + + ss = ss[:2] + fmt.Println(ss) + + ss = ss[1:] + fmt.Println(ss) +} diff --git a/tour_of_go/l4/making-slices.go b/tour_of_go/l4/making-slices.go new file mode 100644 index 0000000..20750f6 --- /dev/null +++ b/tour_of_go/l4/making-slices.go @@ -0,0 +1,41 @@ +package main + +import ( + "fmt" + "strings" +) + +func printSlice(s []int) { + fmt.Printf("len=%d cap=%d %v\n", len(s), cap(s), s) +} + +func main() { + a := make([]int, 5) + printSlice(a) + + b := make([]int, 0, 5) + printSlice(b) + + c := b[:2] + printSlice(c) + + d := c[2:5] + printSlice(d) + + // Slices can contain any type including other slices + board := [][]string{ + []string{"_", "_", "_"}, + []string{"_", "_", "_"}, + []string{"_", "_", "_"}, + } + + board[0][0] = "X" + board[2][2] = "O" + board[1][2] = "X" + board[1][0] = "O" + board[0][2] = "X" + + for i := 0; i < len(board); i++ { + fmt.Printf("%s\n", strings.Join(board[i], " ")) + } +} diff --git a/tour_of_go/l4/pointers.go b/tour_of_go/l4/pointers.go new file mode 100644 index 0000000..9ed7e7d --- /dev/null +++ b/tour_of_go/l4/pointers.go @@ -0,0 +1,18 @@ +package main + +import "fmt" + +func main() { + i, j := 42, 2701 + + p := &i + fmt.Println(*p) + *p = 21 + fmt.Println(i) + + p = &j + *p = *p / 37 + fmt.Println(j) + + fmt.Println(i, j) +} diff --git a/tour_of_go/l4/range.go b/tour_of_go/l4/range.go new file mode 100644 index 0000000..e164638 --- /dev/null +++ b/tour_of_go/l4/range.go @@ -0,0 +1,21 @@ +package main + +import "fmt" + +var pow = []int{1, 2, 4, 8, 16, 32, 64, 128} + +func main() { + for i, v := range pow { + fmt.Printf("2**%d = %d\n", i, v) + } + + // You can skip the index by assigning it to "_" + // Or you can skip the value by omitting the 2nd value -> "for i := range XXX" + new_pow := make([]int, 10) + for i := range new_pow { + new_pow[i] = 1 << uint(i) + } + for _, value := range new_pow { + fmt.Printf("%d\n", value) + } +} diff --git a/tour_of_go/l4/slices-cont.go b/tour_of_go/l4/slices-cont.go new file mode 100644 index 0000000..47ca68f --- /dev/null +++ b/tour_of_go/l4/slices-cont.go @@ -0,0 +1,33 @@ +package main + +import "fmt" + +func printSlice(s []int) { + fmt.Printf("len=%d cap=%d %v\n", len(s), cap(s), s) +} + +func main() { + s := []int{2, 3, 5, 7, 11, 13} + printSlice(s) + + s = s[:0] + printSlice(s) + + s = s[:4] + printSlice(s) + + s = s[2:] + printSlice(s) + + // Extend beyond capacity + // s = s[:10] + // printSlice(s) + + // Zero value of a slice is nil + var ns []int + printSlice(ns) + + if ns == nil { + fmt.Println("nil!!") + } +} diff --git a/tour_of_go/l4/structs.go b/tour_of_go/l4/structs.go new file mode 100644 index 0000000..4438f54 --- /dev/null +++ b/tour_of_go/l4/structs.go @@ -0,0 +1,27 @@ +package main + +import "fmt" + +type Vertex struct { + X int + Y int +} + +var ( + v1 = Vertex{1, 2} + v2 = Vertex{X: 1} + v3 = Vertex{} + p = &Vertex{1, 2} +) + +func main() { + v := Vertex{1, 2} + v.X = 4 + fmt.Println(v) + + o := &v + o.X = 12 + fmt.Printf("New vertex value is %d\n", v) + + fmt.Println(v1, p, v2, v3) +} diff --git a/using_modules/go.mod b/using_modules/go.mod new file mode 100644 index 0000000..9557942 --- /dev/null +++ b/using_modules/go.mod @@ -0,0 +1,3 @@ +module learning.local/using_modules + +go 1.24.5 diff --git a/using_modules/using_modules.go b/using_modules/using_modules.go new file mode 100644 index 0000000..ecbd885 --- /dev/null +++ b/using_modules/using_modules.go @@ -0,0 +1,54 @@ +package using_modules + +import ( + "fmt" + "errors" + "math/rand" +) + +// Hello returns a greeting for the named person +func Hello(name string) (string, error) { + // If no name was given, return an error with a message + if name == "" { + return "", errors.New("empty name") + } + + message := fmt.Sprintf(randomFormat(), name) + return message, nil +} + +// Hellos retruns a map that associates each of the named people +// with a greeting message. +func Hellos(names []string) (map[string]string, error) { + // A map to associate names with messages + messages := make(map[string]string) + // Loop through the received slice of names, calling + // the Hello function to get a message for each name. + for _, name := range names { + message, err := Hello(name) + if err != nil { + return nil, err + } + // In the map, associate the terieved message with + // the name. + messages[name] = message + } + return messages, nil +} + + +// randomFormat returns one of a set of greeting messages. The returned +// message is selected at random. + +func randomFormat() string { + // A slice of message formats + formats := []string{ + "Hi, %v. Welcome!", + "Great to see you, %v!", + "Hail, %v! Well met!", + } + + // Return a randomly selected message format by specifying + // a random index for the slice of formats. + return formats[rand.Intn(len(formats))] +} diff --git a/using_modules/using_modules_test.go b/using_modules/using_modules_test.go new file mode 100644 index 0000000..71ed32b --- /dev/null +++ b/using_modules/using_modules_test.go @@ -0,0 +1,26 @@ +package using_modules + +import ( + "testing" + "regexp" +) + +// TestHelloName calls greetings.Hello with a name, checking +// for a valid return value. +func TestHelloName(t *testing.T) { + name := "Gladys" + want := regexp.MustCompile(`\b`+name+`\b`) + msg, err := Hello("Gladys") + if !want.MatchString(msg) || err != nil { + t.Errorf(`Hello("Gladys") = %q, %v, want match for %#q, nill`, msg, err, want) + } +} + +// TestHelloEmpty calls greeting.Hello with an empty string, +// checking for an error +func TestHelloEmpty(t *testing.T) { + msg, err := Hello("") + if msg != "" || err == nil { + t.Errorf(`Hello("") = %q, %v, want "", error`, msg, err) + } +}