memio - example_test.go

     1  package memio_test
     2  
     3  import (
     4  	"errors"
     5  	"fmt"
     6  	"io"
     7  
     8  	"vimagination.zapto.org/memio"
     9  )
    10  
    11  // ExampleBuffer demonstrates writing and reading using Buffer.
    12  func ExampleBuffer() {
    13  	var buf memio.Buffer
    14  
    15  	buf.WriteString("Hello, world!")
    16  
    17  	data := make([]byte, 5)
    18  
    19  	buf.Read(data)
    20  
    21  	fmt.Printf("%s", data)
    22  	// Output: Hello
    23  }
    24  
    25  // ExampleLimitedBuffer shows how LimitedBuffer prevents writes beyond capacity.
    26  func ExampleLimitedBuffer() {
    27  	// Preallocate 5 bytes
    28  	data := make([]byte, 5)
    29  	lb := memio.LimitedBuffer(data)
    30  
    31  	// Write exactly 5 bytes
    32  	lb.WriteString("12345")
    33  
    34  	// Attempting to write more will not extend capacity
    35  	n, err := lb.WriteString("678")
    36  	fmt.Println(n, errors.Is(err, io.ErrShortBuffer))
    37  	// Output: 0 true
    38  }
    39