comma-separated-string.go

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"strings"
)

func main() {
	csvstring := "name, age, occupation"

	// An anonymous function declaration to avoid repeating main()
	ScanCSV := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		commaidx := bytes.IndexByte(data, ',')
		if commaidx > 0 {
			// we need to return the next position
			buffer := data[:commaidx]
			return commaidx + 1, bytes.TrimSpace(buffer), nil
		}

		// if we are at the end of the string, just return the entire buffer
		if atEOF {
			// but only do that when there is some data. If not, this might mean
			// that we've reached the end of our input CSV string
			if len(data) > 0 {
				return len(data), bytes.TrimSpace(data), nil
			}
		}

		// when 0, nil, nil is returned, this is a signal to the interface to read
		// more data in from the input reader. In this case, this input is our
		// string reader and this pretty much will never occur.
		return 0, nil, nil
	}

	scanner := bufio.NewScanner(strings.NewReader(csvstring))
	scanner.Split(ScanCSV)

	for scanner.Scan() {
		fmt.Println(scanner.Text())
	}
}