From 5394aa9a2b7a0a1a4f6e340f68592096924425d9 Mon Sep 17 00:00:00 2001
From: Jack Christensen <jack@jackchristensen.com>
Date: Tue, 4 Apr 2017 08:04:40 -0500
Subject: [PATCH] Add pgtype.Line

---
 pgtype/line.go      | 148 ++++++++++++++++++++++++++++++++++++++++++++
 pgtype/line_test.go |  21 +++++++
 pgtype/pgtype.go    |   1 +
 v3.md               |   1 -
 4 files changed, 170 insertions(+), 1 deletion(-)
 create mode 100644 pgtype/line.go
 create mode 100644 pgtype/line_test.go

diff --git a/pgtype/line.go b/pgtype/line.go
new file mode 100644
index 00000000..08a74e84
--- /dev/null
+++ b/pgtype/line.go
@@ -0,0 +1,148 @@
+package pgtype
+
+import (
+	"database/sql/driver"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/jackc/pgx/pgio"
+)
+
+type Line struct {
+	A, B, C float64
+	Status  Status
+}
+
+func (dst *Line) Set(src interface{}) error {
+	return fmt.Errorf("cannot convert %v to Line", src)
+}
+
+func (dst *Line) Get() interface{} {
+	switch dst.Status {
+	case Present:
+		return dst
+	case Null:
+		return nil
+	default:
+		return dst.Status
+	}
+}
+
+func (src *Line) AssignTo(dst interface{}) error {
+	return fmt.Errorf("cannot assign %v to %T", src, dst)
+}
+
+func (dst *Line) DecodeText(ci *ConnInfo, src []byte) error {
+	if src == nil {
+		*dst = Line{Status: Null}
+		return nil
+	}
+
+	if len(src) < 7 {
+		return fmt.Errorf("invalid length for Line: %v", len(src))
+	}
+
+	parts := strings.SplitN(string(src[1:len(src)-1]), ",", 3)
+	if len(parts) < 3 {
+		return fmt.Errorf("invalid format for line")
+	}
+
+	a, err := strconv.ParseFloat(parts[0], 64)
+	if err != nil {
+		return err
+	}
+
+	b, err := strconv.ParseFloat(parts[1], 64)
+	if err != nil {
+		return err
+	}
+
+	c, err := strconv.ParseFloat(parts[2], 64)
+	if err != nil {
+		return err
+	}
+
+	*dst = Line{A: a, B: b, C: c, Status: Present}
+	return nil
+}
+
+func (dst *Line) DecodeBinary(ci *ConnInfo, src []byte) error {
+	if src == nil {
+		*dst = Line{Status: Null}
+		return nil
+	}
+
+	if len(src) != 24 {
+		return fmt.Errorf("invalid length for Line: %v", len(src))
+	}
+
+	a := binary.BigEndian.Uint64(src)
+	b := binary.BigEndian.Uint64(src[8:])
+	c := binary.BigEndian.Uint64(src[16:])
+
+	*dst = Line{
+		A:      math.Float64frombits(a),
+		B:      math.Float64frombits(b),
+		C:      math.Float64frombits(c),
+		Status: Present,
+	}
+	return nil
+}
+
+func (src *Line) EncodeText(ci *ConnInfo, w io.Writer) (bool, error) {
+	switch src.Status {
+	case Null:
+		return true, nil
+	case Undefined:
+		return false, errUndefined
+	}
+
+	_, err := io.WriteString(w, fmt.Sprintf(`{%f,%f,%f}`, src.A, src.B, src.C))
+	return false, err
+}
+
+func (src *Line) EncodeBinary(ci *ConnInfo, w io.Writer) (bool, error) {
+	switch src.Status {
+	case Null:
+		return true, nil
+	case Undefined:
+		return false, errUndefined
+	}
+
+	if _, err := pgio.WriteUint64(w, math.Float64bits(src.A)); err != nil {
+		return false, err
+	}
+
+	if _, err := pgio.WriteUint64(w, math.Float64bits(src.B)); err != nil {
+		return false, err
+	}
+
+	_, err := pgio.WriteUint64(w, math.Float64bits(src.C))
+	return false, err
+}
+
+// Scan implements the database/sql Scanner interface.
+func (dst *Line) Scan(src interface{}) error {
+	if src == nil {
+		*dst = Line{Status: Null}
+		return nil
+	}
+
+	switch src := src.(type) {
+	case string:
+		return dst.DecodeText(nil, []byte(src))
+	case []byte:
+		return dst.DecodeText(nil, src)
+	}
+
+	return fmt.Errorf("cannot scan %T", src)
+}
+
+// Value implements the database/sql/driver Valuer interface.
+func (src *Line) Value() (driver.Value, error) {
+	return encodeValueText(src)
+}
diff --git a/pgtype/line_test.go b/pgtype/line_test.go
new file mode 100644
index 00000000..6d3b02e1
--- /dev/null
+++ b/pgtype/line_test.go
@@ -0,0 +1,21 @@
+package pgtype_test
+
+import (
+	"testing"
+
+	"github.com/jackc/pgx/pgtype"
+)
+
+func TestLineTranscode(t *testing.T) {
+	testSuccessfulTranscode(t, "line", []interface{}{
+		&pgtype.Line{
+			A: 1.23, B: 4.56, C: 7.89,
+			Status: pgtype.Present,
+		},
+		&pgtype.Line{
+			A: -1.23, B: -4.56, C: -7.89,
+			Status: pgtype.Present,
+		},
+		&pgtype.Line{Status: pgtype.Null},
+	})
+}
diff --git a/pgtype/pgtype.go b/pgtype/pgtype.go
index b29bc90c..c92dfccf 100644
--- a/pgtype/pgtype.go
+++ b/pgtype/pgtype.go
@@ -242,6 +242,7 @@ func init() {
 		"int8range":    &Int8range{},
 		"json":         &Json{},
 		"jsonb":        &Jsonb{},
+		"line":         &Line{},
 		"name":         &Name{},
 		"numeric":      &Numeric{},
 		"numrange":     &Numrange{},
diff --git a/v3.md b/v3.md
index 1930508f..38cf18cf 100644
--- a/v3.md
+++ b/v3.md
@@ -68,7 +68,6 @@ something like:
 select array[1,2,3], array[4,5,6,7]
 
 pgtype TODO:
-line
 lseg
 path
 path