Go Core Concepts

Object Model / Type System

Interfaces

• Interface definition and implementation
• Empty interface
• Type assertions and type switches
• Best practices for interface design

Structs

• Struct definition
• Embedding and composition
• Methods and receivers
• Tags and reflection

Type System Features

• Type aliases
• Type embedding
• Type constraints (Go 1.18+)
• Type inference

Memory Management

Memory Model

• Stack vs Heap allocation
• Value vs Pointer semantics
• Escape analysis
• Memory layout and alignment

Garbage Collection

• GC algorithm overview
• GC tuning and optimization
• Memory profiling
• Best practices for memory management

Concurrency Pattern

Goroutine Patterns

• Worker pools
• Pipeline patterns
• Fan-out/Fan-in
• Rate limiting

Channel Patterns

• Generator pattern
• Multiplexing with select
• Done channel pattern
• Error handling in concurrent code

// Generator pattern example
func fibonacci(n int) <-chan int {
    out := make(chan int)
    go func() {
        defer close(out)
        a, b := 0, 1
        for i := 0; i < n; i++ {
            out <- a
            a, b = b, a+b
        }
    }()
    return out
}

// Multiplexing with select
func merge(cs ...<-chan int) <-chan int {
    out := make(chan int)
    var wg sync.WaitGroup
    wg.Add(len(cs))

    for _, c := range cs {
        go func(ch <-chan int) {
            defer wg.Done()
            for n := range ch {
                out <- n
            }
        }(c)
    }

    go func() {
        wg.Wait()
        close(out)
    }()

    return out
}

// Usage example
func main() {
    ch1 := fibonacci(5)
    ch2 := fibonacci(3)
    for n := range merge(ch1, ch2) {
        fmt.Println(n)
    }
}

Synchronization Patterns

• Mutex patterns
• Once patterns
• Atomic operations
• Context usage

I/O Model

I/O Interfaces

• io.Reader and io.Writer
• io.ReadWriter
• bufio package
• ioutil utilities

File Operations

• File reading and writing
• Directory operations
• File system abstractions
• Temporary files

Network I/O

• TCP/UDP networking
• HTTP client/server
• WebSocket support
• Connection pooling

Exception Handling

Error Handling Patterns

1. Basic Error Handling

   if err != nil {
       return fmt.Errorf("operation failed: %w", err)
   }

2. Custom Error Types

   type CustomError struct {
       Code    int
       Message string
   }
   
   func (e *CustomError) Error() string {
       return fmt.Sprintf("error %d: %s", e.Code, e.Message)
   }

Panic and Recovery

• When to use panic
• Recover mechanism
• Defer patterns
• Error vs Panic