formats/config: Added encoder/decoder for git config files. (#97)

* WIP: Add config format parser.

* add decoder based on gcfg.

Portions of code taken from:
https://github.com/go-gcfg/gcfg/blob/5b9f94ee80b2331c3982477bd84be8edd857df33/read.go

* add git config encoder and config methods.

* use format/config in storage/filesystem for read

* use format/config in storage/filesystem to write

* formats/config: improve docs.

* formats/config: improve tests.

* formats/config: use our fork of gcfg; improve api.

* formats/config: improve api.

* storage/filesystem: fix gofmt

* formats/config: use NoSubsection constant.

* formats/config: add doc.go

* formats/config: requested sytle changes.

* formats/config: do not use *_test packages.

1 files changed, 38 insertions, 0 deletions

diff --git a/formats/config/encoder.go b/formats/config/encoder.go
new file mode 100644
index 0000000..4a68e44
--- /dev/null
+++ b/formats/config/encoder.go
@@ -0,0 +1,38 @@
+package config
+
+import (
+	"fmt"
+	"io"
+)
+
+// An Encoder writes config files to an output stream.
+type Encoder struct {
+	io.Writer
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{w}
+}
+
+// Encode writes the config in git config format to the stream of the encoder.
+func (e *Encoder) Encode(cfg *Config) error {
+	for _, s := range cfg.Sections {
+		if len(s.Options) > 0 {
+			fmt.Fprintf(e, "[%s]\n", s.Name)
+			for _, o := range s.Options {
+				fmt.Fprintf(e, "\t%s = %s\n", o.Key, o.Value)
+			}
+		}
+		for _, ss := range s.Subsections {
+			if len(ss.Options) > 0 {
+				//TODO: escape
+				fmt.Fprintf(e, "[%s \"%s\"]\n", s.Name, ss.Name)
+				for _, o := range ss.Options {
+					fmt.Fprintf(e, "\t%s = %s\n", o.Key, o.Value)
+				}
+			}
+		}
+	}
+	return nil
+}