merge backend refactoring from main

1 files changed, 33 insertions, 0 deletions

diff --git a/volume.go b/volume.go
new file mode 100644
index 0000000..6f5fb31
--- /dev/null
+++ b/volume.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+type Volume float32
+
+const (
+	CubicCentimetre Volume = 1
+	Litre           Volume = 1_000
+	CubicMetre      Volume = 1_000_000
+	CubicInch       Volume = 16.38706
+)
+
+var VolumeUnits = []string{"cc", "L", "m³", "in³"}
+
+func ParseVolumeUnit(s string) (Volume, error) {
+	// Each case corresponds to a value in VolumeUnits.
+	switch s {
+	case "cc":
+		return CubicCentimetre, nil
+	case "L":
+		return Litre, nil
+	case "m³":
+		return CubicMetre, nil
+	case "in³":
+		return CubicInch, nil
+	default:
+		return *new(Volume), errors.New(fmt.Sprintf("invalid volume unit: '%s'", s))
+	}
+}