From 29baa531948de1a2478a47d04bbab14012dc4c15 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Wed, 28 Oct 2020 12:57:11 +0300
Subject: [PATCH] Writer

---
 README   |  7 +++---
 field.go | 24 +++++++++++++++++++++
 r.go     |  5 -----
 w.go     | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 93 insertions(+), 8 deletions(-)
 create mode 100644 field.go
 create mode 100644 w.go

diff --git a/README b/README
index 23f1fa3..c9ab1aa 100644
--- a/README
+++ b/README
@@ -1,6 +1,7 @@
-GNU recutils'es recfile parser on pure Go. recfiles are human-editable,
-plaintext databases. This library allows you to read records and their
-fields from it. Look for cmd/gorecsel as an example usage.
+GNU recutils'es recfile parser/writer on pure Go.
+recfiles are human-editable, plaintext databases. This library allows
+you to read records and their fields from it. Look for cmd/gorecsel as
+an example usage.
 
 * iterate through the records and their fields
 * ignore comments
diff --git a/field.go b/field.go
new file mode 100644
index 0000000..887ccdb
--- /dev/null
+++ b/field.go
@@ -0,0 +1,24 @@
+/*
+recfile -- GNU recutils'es recfiles parser on pure Go
+Copyright (C) 2020 Sergey Matveev <stargrave@stargrave.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 3 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// GNU recutils'es recfiles parser on pure Go
+package recfile
+
+type Field struct {
+	Name  string
+	Value string
+}
diff --git a/r.go b/r.go
index 9a4420d..2b917ae 100644
--- a/r.go
+++ b/r.go
@@ -38,11 +38,6 @@ func NewReader(r io.Reader) *Reader {
 	return &Reader{bufio.NewScanner(r)}
 }
 
-type Field struct {
-	Name  string
-	Value string
-}
-
 // Get next record. Each record is just a collection of fields. io.EOF
 // is returned if there is nothing to read more.
 func (r *Reader) Next() ([]Field, error) {
diff --git a/w.go b/w.go
new file mode 100644
index 0000000..fd71e18
--- /dev/null
+++ b/w.go
@@ -0,0 +1,65 @@
+/*
+recfile -- GNU recutils'es recfiles parser on pure Go
+Copyright (C) 2020 Sergey Matveev <stargrave@stargrave.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 3 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// GNU recutils'es recfiles parser on pure Go
+package recfile
+
+import (
+	"io"
+	"strings"
+)
+
+type Writer struct {
+	w io.StringWriter
+}
+
+func NewWriter(w io.StringWriter) *Writer {
+	return &Writer{w}
+}
+
+func (w *Writer) RecordStart(fs ...Field) (written int, err error) {
+	return w.w.WriteString("\n")
+}
+
+func (w *Writer) WriteFields(fs ...Field) (written int, err error) {
+	var n int
+	for _, f := range fs {
+		n, err = w.w.WriteString(f.Name + ": " + strings.TrimLeft(f.Value, " ") + "\n")
+		written += n
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+func (w *Writer) WriteFieldMultiline(name string, lines []string) (written int, err error) {
+	var n int
+	n, err = w.w.WriteString(name + ": " + strings.TrimLeft(lines[0], " ") + "\n")
+	written += n
+	if err != nil {
+		return
+	}
+	for _, l := range lines[1:] {
+		n, err = w.w.WriteString("+ " + l + "\n")
+		written += n
+		if err != nil {
+			return
+		}
+	}
+	return
+}
-- 
2.44.0