Merge pull request #3 from webguerilla/master

Scanner and Valuer interface

README.md

@@ -72,9 +72,10 @@ The generated code is exactly the same as the Stringer tool plus the mentioned a
 The usage of Enumer is the same as Stringer, so you can refer to the [Stringer docs](https://godoc.org/golang.org/x/tools/cmd/stringer)
 for more information.
 
-As mentioned before, there is only one flag added: `json`.
+There are two flags added: `json` and `sql`. If the json flag is set to true (i.e. `enumer -type=Pill -json`), 
+the JSON related methods will be generated. And if the sql flag is set to true, the Scanner and Valuer interface will 
+be implemented to seamlessly use the enum in a database model.
 
 ## Inspiring projects
 * [Stringer](https://godoc.org/golang.org/x/tools/cmd/stringer)
 * [jsonenums](https://github.com/campoy/jsonenums)
-

sql.go

@@ -0,0 +1,40 @@
+package main
+
+// Arguments to format are:
+//	[1]: type name
+const valueMethod = `func (i %[1]s) Value() (driver.Value, error) {
+	return i.String(), nil
+}
+`
+
+const scanMethod = `func (i *%[1]s) Scan(value interface{}) error {
+	if value == nil {
+		return nil
+	}
+
+	str, ok := value.(string)
+	if !ok {
+		bytes, ok := value.([]byte)
+		if !ok {
+			return fmt.Errorf("value is not a byte slice")
+		}
+
+		str = string(bytes[:])
+	}
+
+	val, err := %[1]sString(str)
+	if err != nil {
+		return err
+	}
+	
+	*i = val
+	return nil
+}
+`
+
+func (g *Generator) addValueAndScanMethod(typeName string) {
+	g.Printf("\n")
+	g.Printf(valueMethod, typeName)
+	g.Printf("\n\n")
+	g.Printf(scanMethod, typeName)
+}

stringer.go

@@ -82,6 +82,7 @@ import (
 
 var (
 	typeNames = flag.String("type", "", "comma-separated list of type names; must be set")
+	sql       = flag.Bool("sql", false, "if true, the Scanner and Valuer interface will be implemented.")
 	json      = flag.Bool("json", false, "if true, json marshaling methods will be generated. Default: false")
 	output    = flag.String("output", "", "output file name; default srcdir/<type>_string.go")
 )
@@ -133,10 +134,15 @@ func main() {
 	g.Printf("\n")
 	g.Printf("package %s", g.pkg.name)
 	g.Printf("\n")
-	g.Printf("import \"fmt\"\n") // Used by all methods.
-	if *json {
-		g.Printf("import \"encoding/json\"\n")
+	g.Printf("import (\n")
+	g.Printf("\t\"fmt\"\n")
+	if *sql {
+		g.Printf("\t\"database/sql/driver\"\n")
 	}
+	if *json {
+		g.Printf("\t\"encoding/json\"\n")
+	}
+	g.Printf(")\n")
 
 	// Run generate for each type.
 	for _, typeName := range types {
@@ -313,11 +319,17 @@ func (g *Generator) generate(typeName string, includeJSON bool) {
 	default:
 		g.buildMap(runs, typeName)
 	}
+
 	// ENUMER part
 	g.buildValueToNameMap(runs, typeName, runsThreshold)
 	if includeJSON {
 		g.buildJSONMethods(runs, typeName, runsThreshold)
 	}
+
+	// SQL
+	if *sql {
+		g.addValueAndScanMethod(typeName)
+	}
 }
 
 // splitIntoRuns breaks the values into runs of contiguous sequences.