Add structs

main.go

@@ -0,0 +1,9 @@
+package main
+
+// import "git.sangeeth.dev/gobyexample/runes"
+import "git.sangeeth.dev/gobyexample/structs"
+
+func main() {
+	// runes.Runes()
+	structs.Structs()
+}

runes/runes.go

@@ -0,0 +1,26 @@
+package runes
+
+import (
+	"fmt"
+	"unicode/utf8"
+)
+
+func Runes() {
+	s := "Hello, world!"
+	fmt.Printf("%s has %d runes\n", s, utf8.RuneCountInString(s))
+
+	s = "നമസ്കാരം"
+	fmt.Printf("%s has %d runes\n", s, utf8.RuneCountInString(s))
+
+	fmt.Printf("Iterating through %s:\n", s)
+	for i, val := range s {
+		fmt.Printf("%2d = %#U\n", i, val)
+	}
+
+	fmt.Printf("Decoding %s:\n", s)
+	for i, w := 0, 0; i < len(s); i += w {
+		value, width := utf8.DecodeRuneInString(s[i:])
+		fmt.Printf("Decoded rune %#U of size %d\n", value, width)
+		w = width
+	}
+}

structs/structs.go

@@ -0,0 +1,90 @@
+package structs
+
+import (
+	"fmt"
+	"math"
+)
+
+type ShapeMetadata struct {
+	Id   int
+	Name string
+}
+
+type Shape interface {
+	Area() float64
+	Perimeter() float64
+}
+
+type Square struct {
+	ShapeMetadata
+	Size float64
+}
+
+type Rectangle struct {
+	ShapeMetadata
+	Length, Breadth float64
+}
+
+type Triangle struct {
+	ShapeMetadata
+	A, B, C float64
+}
+
+func (s *Square) Area() float64 {
+	return s.Size * s.Size
+}
+
+func (s *Square) Perimeter() float64 {
+	return 4 * s.Size
+}
+
+func (r *Rectangle) Area() float64 {
+	return r.Length * r.Breadth
+}
+
+func (r *Rectangle) Perimeter() float64 {
+	return 2 * (r.Length + r.Breadth)
+}
+
+func (t *Triangle) Area() float64 {
+	s := (t.A + t.B + t.C) / 2
+	area := math.Sqrt(s * (s - t.A) * (s - t.B) * (s - t.C))
+	return area
+}
+
+func (t *Triangle) Perimeter() float64 {
+	return t.A + t.B + t.C
+}
+
+func Structs() {
+	sq := Square{
+		ShapeMetadata: ShapeMetadata{
+			Id:   0,
+			Name: "mysquare",
+		},
+		Size: 10.0,
+	}
+
+	rect := Rectangle{
+		ShapeMetadata: ShapeMetadata{
+			Id:   0,
+			Name: "myrectangle",
+		},
+		Length:  10,
+		Breadth: 5,
+	}
+
+	tri := Triangle{
+		ShapeMetadata: ShapeMetadata{
+			Id:   0,
+			Name: "mytriangle",
+		},
+		A: 2,
+		B: 2,
+		C: 2,
+	}
+
+	fmt.Printf("Triangle: Area = %.2f Perimeter = %.2f\n", tri.Area(), tri.Perimeter())
+	fmt.Printf("Rectangle: Area = %.2f Perimeter = %.2f\n", rect.Area(), rect.Perimeter())
+	fmt.Printf("Square: Area = %.2f Perimeter = %.2f\n", sq.Area(), sq.Perimeter())
+}