main.go

package main

import (
	"compress/gzip"
	"encoding/json"
	"fmt"
	"log"
	"os"
)

func main() {

	//This struct acts as a model for the JSON you are reading
	type Sample struct {
		Name      string `json:"name"`
		Accession string `json:"accession"`
	}

	inputFile := os.Args[1]

	f, err := os.Open(inputFile)
	if err != nil {
		log.Fatal(err)
	}

	gz, err := gzip.NewReader(f)
	if err != nil {
		log.Fatal(err)
	}

	defer f.Close()
	defer gz.Close()

	dec := json.NewDecoder(gz)

	// read open bracket
	_, err = dec.Token()
	if err != nil {
		log.Fatal(err)
	}

	// while the array contains values
	for dec.More() {
		var s Sample
		// decode an array value (Sample)
		err := dec.Decode(&s)
		if err != nil {
			log.Fatal(err)
		}
		fmt.Printf("%v:%v\n", s.Name, s.Accession)
	}

	// read closing bracket
	_, err = dec.Token()
	if err != nil {
		log.Fatal(err)
	}
}