Add native output format

formats/gomod2nix/gomod2nix.go

@@ -0,0 +1,57 @@
+package gomod2nix
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/BurntSushi/toml"
+	"github.com/tweag/gomod2nix/types"
+	"io/ioutil"
+)
+
+type packageT struct {
+	Type   string `toml:"type"`
+	URL    string `toml:"url"`
+	Rev    string `toml:"rev"`
+	Sha256 string `toml:"sha256"`
+}
+
+func Marshal(pkgs []*types.Package) ([]byte, error) {
+	result := make(map[string]*packageT)
+
+	for _, pkg := range pkgs {
+		result[pkg.GoPackagePath] = &packageT{
+			Type:   "git",
+			URL:    pkg.URL,
+			Rev:    pkg.Rev,
+			Sha256: pkg.Sha256,
+		}
+	}
+
+	var buf bytes.Buffer
+	e := toml.NewEncoder(&buf)
+	err := e.Encode(result)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
+func LoadGomod2Nix(filePath string) map[string]*types.Package {
+	ret := make(map[string]*types.Package)
+
+	b, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		fmt.Println(err)
+		return ret
+	}
+
+	result := make(map[string]*packageT)
+	_, err = toml.Decode(string(b), &result)
+	if err != nil {
+		fmt.Println(err)
+		return ret
+	}
+
+	return ret
+}

go.mod

@@ -3,6 +3,7 @@ module github.com/tweag/gomod2nix
 go 1.14
 
 require (
+	github.com/BurntSushi/toml v0.3.1
 	github.com/orivej/go-nix v0.0.0-20180830055821-dae45d921a44
 	golang.org/x/mod v0.3.0
 	golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e

go.sum

@@ -1,3 +1,5 @@
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/alecthomas/assert v0.0.0-20170929043011-405dbfeb8e38 h1:smF2tmSOzy2Mm+0dGI2AIUHY+w0BUc+4tn40djz7+6U=
 github.com/alecthomas/assert v0.0.0-20170929043011-405dbfeb8e38/go.mod h1:r7bzyVFMNntcxPZXK3/+KdruV1H5KSlyVY0gc+NgInI=
 github.com/alecthomas/colour v0.0.0-20160524082231-60882d9e2721 h1:JHZL0hZKJ1VENNfmXvHbgYlbUOvpzYzvy2aZU5gXVeo=

main.go

@@ -4,7 +4,8 @@ import (
 	"flag"
 	"fmt"
 	"github.com/tweag/gomod2nix/fetch"
-	"github.com/tweag/gomod2nix/formats/buildgopackage"
+	// "github.com/tweag/gomod2nix/formats/buildgopackage"
+	"github.com/tweag/gomod2nix/formats/gomod2nix"
 	"path/filepath"
 )
 
@@ -21,7 +22,8 @@ func main() {
 		panic(err)
 	}
 
-	output, err := buildgopackage.Marshal(pkgs)
+	// output, err := buildgopackage.Marshal(pkgs)
+	output, err := gomod2nix.Marshal(pkgs)
 	if err != nil {
 		panic(err)
 	}