Merge pull request #2 from axiomzen/add-mapping

Add mapping support.

README.md

@@ -22,6 +22,7 @@ export MYAPP_USER=Kelsey
 export MYAPP_RATE="0.5"
 export MYAPP_TIMEOUT="3m"
 export MYAPP_USERS="rob,ken,robert"
+export MYAPP_COLORCODES="red:1,green:2,blue:3"
 ```
 
 Write some code:
@@ -34,16 +35,17 @@ import (
     "log"
     "time"
 
-    "github.com/kelseyhightower/envconfig"
+    "github.com/axiomzen/envconfig"
 )
 
 type Specification struct {
-    Debug   bool
-    Port    int
-    User    string
-    Users   []string
-    Rate    float32
-    Timeout time.Duration
+    Debug       bool
+    Port        int
+    User        string
+    Users       []string
+    Rate        float32
+    Timeout     time.Duration
+    ColorCodes  map[string]int
 }
 
 func main() {
@@ -62,6 +64,11 @@ func main() {
     for _, u := range s.Users {
         fmt.Printf("  %s\n", u)
     }
+
+     fmt.Println("Color codes:")
+        for k, v := range s.ColorCodes {
+            fmt.Printf("  %s: %d\n", k, v)
+        }
 }
 ```
 
@@ -77,6 +84,10 @@ Users:
   rob
   ken
   robert
+Color codes:
+  red: 1
+  green: 2
+  blue: 3  
 ```
 
 ## Struct Tag Support
@@ -136,6 +147,8 @@ envconfig supports supports these struct field types:
   * int8, int16, int32, int64
   * bool
   * float32, float64
+  * slices of any supported type
+  * maps (keys and values of any supported type)
 
 Embedded structs using these fields are also supported.
 

envconfig.go

@@ -178,6 +178,27 @@ func processField(value string, field reflect.Value) error {
 			}
 		}
 		field.Set(sl)
+	case reflect.Map:
+		pairs := strings.Split(value, ",")
+		mp := reflect.MakeMap(typ)
+		for _, pair := range pairs {
+			kvpair := strings.Split(pair, ":")
+			if len(kvpair) != 2 {
+				return fmt.Errorf("invalid map item: %q", pair)
+			}
+			k := reflect.New(typ.Key()).Elem()
+			err := processField(kvpair[0], k)
+			if err != nil {
+				return err
+			}
+			v := reflect.New(typ.Elem()).Elem()
+			err = processField(kvpair[1], v)
+			if err != nil {
+				return err
+			}
+			mp.SetMapIndex(k, v)
+		}
+		field.Set(mp)
 	}
 
 	return nil

envconfig_test.go

@@ -23,6 +23,7 @@ type Specification struct {
 	Timeout                      time.Duration //10
 	AdminUsers                   []string
 	MagicNumbers                 []int
+	ColorCodes                   map[string]int
 	MultiWordVar                 string
 	SomePointer                  *string
 	SomePointerWithDefault       *string       `default:"foo2baz"` //15
@@ -65,6 +66,7 @@ func TestProcess(t *testing.T) {
 	os.Setenv("ENV_CONFIG_TIMEOUT", "2m")
 	os.Setenv("ENV_CONFIG_ADMINUSERS", "John,Adam,Will")
 	os.Setenv("ENV_CONFIG_MAGICNUMBERS", "5,10,20")
+	os.Setenv("ENV_CONFIG_COLORCODES", "red:1,green:2,blue:3")
 	os.Setenv("SERVICE_HOST", "127.0.0.1")
 	os.Setenv("ENV_CONFIG_TTL", "30")
 	os.Setenv("ENV_CONFIG_REQUIREDVAR", "foo")
@@ -126,6 +128,21 @@ func TestProcess(t *testing.T) {
 		t.Errorf("expected empty string, got %#v", s.Ignored)
 	}
 
+	if len(s.ColorCodes) != 3 ||
+		s.ColorCodes["red"] != 1 ||
+		s.ColorCodes["green"] != 2 ||
+		s.ColorCodes["blue"] != 3 {
+		t.Errorf(
+			"expected %#v, got %#v",
+			map[string]int{
+				"red":   1,
+				"green": 2,
+				"blue":  3,
+			},
+			s.ColorCodes,
+		)
+	}
+
 	if s.DefaultInt != 7 {
 		t.Errorf("expected %d, got %d", 7, s.DefaultInt)
 	}