Implement MyStringReader and MyLimitReader with example usage in main function

Author: s1thu

go_programming_pdf_learning/chapter7/exercise_7.4.go

@@ -0,0 +1,16 @@
+package main
+
+import "io"
+
+type MyStringReader struct {
+	s string
+}
+
+func (r *MyStringReader) Read(p []byte) (n int, err error) {
+	if len(r.s) == 0 {
+		return 0, io.EOF
+	}
+	n = copy(p, r.s)
+	r.s = r.s[n:]
+	return n, nil
+}

go_programming_pdf_learning/chapter7/exercise_7.5.go

@@ -0,0 +1,28 @@
+package main
+
+import "io"
+
+type MyLimitReader struct {
+	r         io.Reader // underlying reader
+	remaining int64     // how many bytes left to read
+}
+
+func (l *MyLimitReader) Read(p []byte) (n int, err error) {
+	if l.remaining <= 0 {
+		return 0, io.EOF
+	}
+
+	// shrink p if it’s bigger than remaining
+	if int64(len(p)) > l.remaining {
+		p = p[:l.remaining]
+	}
+
+	n, err = l.r.Read(p)
+	l.remaining -= int64(n)
+	return n, err
+}
+
+// Constructor function
+func LimitReader(r io.Reader, n int64) io.Reader {
+	return &MyLimitReader{r: r, remaining: n}
+}

go_programming_pdf_learning/chapter7/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+	"io"
+)
+
+// func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error)
+
+// func Printf(format string, a ...interface{}) (n int, err error) {
+// 	return Fprintf(os.Stdout, format, a...)
+// }
+
+// func Sprintf(format string, args ...interface{}) string {
+// 	var buf bytes.Buffer
+// 	Fprintf(&buf, format, args...)
+// 	return buf.String()
+// }
+
+func main() {
+	r := &MyStringReader{s: "Hello, Reader!"}
+	limited := LimitReader(r, 5) // li
+	buf := make([]byte, 10)      // read in chunks
+	for {
+		n, err := limited.Read(buf)
+		if n > 0 {
+			fmt.Printf("Read: %q\n", buf[:n])
+		}
+		if err == io.EOF {
+			fmt.Println("Reached limit!")
+			break
+		}
+	}
+}

interface/golinuxcloud/main.go

@@ -0,0 +1,53 @@
+package main
+
+import "fmt"
+
+type salaryCalculator interface {
+	calculateSalary() float64
+	report()
+}
+
+type PermanentEmployee struct {
+	id          int
+	basicSalary float64
+	commission  float64
+}
+
+type ContractEmployee struct {
+	id          int
+	basicSalary float64
+}
+
+func (p PermanentEmployee) calculateSalary() float64 {
+	return p.basicSalary + (p.commission/100)*p.basicSalary
+}
+
+func (c ContractEmployee) calculateSalary() float64 {
+	return c.basicSalary
+}
+
+func (p PermanentEmployee) report() {
+	fmt.Printf("Employee ID %d earns USD %f per month \n", p.id, p.calculateSalary())
+}
+
+func (c ContractEmployee) report() {
+	fmt.Printf("Employee ID %d earns USD %f per month \n", c.id, c.calculateSalary())
+}
+
+func main() {
+	p1 := PermanentEmployee{id: 1, basicSalary: 2300, commission: 13}
+	p2 := PermanentEmployee{id: 2, basicSalary: 1500, commission: 18}
+	p3 := PermanentEmployee{id: 3, basicSalary: 2300, commission: 10}
+	c1 := ContractEmployee{id: 4, basicSalary: 500}
+	c2 := ContractEmployee{id: 5, basicSalary: 1100}
+	c3 := ContractEmployee{id: 6, basicSalary: 700}
+
+	employees := []salaryCalculator{p1, p2, p3, c1, c2, c3}
+
+	var totalSalary float64
+
+	for _, employee := range employees {
+		totalSalary += employee.calculateSalary()
+	}
+	fmt.Printf("Company total salary is : USD %f", totalSalary)
+}

q1.py

@@ -0,0 +1,13 @@
+def divide_numbers_safe():
+    numerator = int(input("Enter numerator: "))
+    denominator = int(input("Enter denominator: "))
+
+    if denominator == 0:
+        print("Error: Division by zero is not allowed.")
+    else:
+        result = numerator / denominator
+        print("Result:", result)
+
+
+if __name__ == "__main__":
+    divide_numbers_safe()