main.go

package main

import (
	"encoding/csv"
	"fmt"
	"io"
	"log"
	"os"
)

const numWorkers = 10

func parseLine(s []string) int {
	return len(s)
}

func makeWorker() (input chan []string, output chan int) {
	input = make(chan []string)
	output = make(chan int)

	// Set up a worker process
	go func() {
		for line := range input {
			output <- parseLine(line)
		}
		close(output)
	}()
	return input, output
}

func main() {
	fmt.Println("vim-go")
	file, err := os.Open("far-poston.csv")
	if err != nil {
		log.Fatal(err)
	}

	// Create numWorkers workers
	var inputs []chan []string
	var outputs []chan int
	for x := 0; x < numWorkers; x++ {
		input, output := makeWorker()
		inputs = append(inputs, input)
		outputs = append(outputs, output)
	}

	// Create a reader in a new goroutine
	go func() {
		r := csv.NewReader(file)
		i := 0
		for {
			record, err := r.Read()
			i++
			if err == io.EOF {
				break
			} else if err != nil {
				return
			}
			// Distribute records to workers in order
			inputs[i%numWorkers] <- record
		}
		// Close out all inputs, so workers know to shutdown
		for _, input := range inputs {
			close(input)
		}
	}()

	var alloutput []int

	j := 0
	for {
		// Read results from outputs in order
		o, ok := <-outputs[j%numWorkers]
		j++
		// If we run into a closed channel, we're done
		if !ok {
			break
		}
		alloutput = append(alloutput, o)
		fmt.Println(o)
	}
}