Add EncodeToStringWith and EncodeToValuesWith convenience functions

README.md

@@ -131,6 +131,29 @@ While encouraged, it is not necessary to define a type (e.g. a `struct`) in orde
 
 By default, and without custom marshaling, zero values (also known as empty/default values) are encoded as the empty string. To disable this behavior, meaning to keep zero values in their literal form (e.g. `0` for integral types), `Encoder` offers a `KeepZeros` setter method, which will do just that when set to `true`.
 
+For instance, given...
+
+```go
+foo := map[string]interface{}{"b": false, "i": 0}
+```
+
+...the following...
+
+```go
+form.EncodeToString(foo) // i.e. keepZeros == false
+```
+
+...will result in `"b=&i="`, whereas...
+
+```go
+keepZeros := true
+delimiter := '.'
+escape := '\\'
+form.EncodeToStringWith(foo, delimiter, escape, keepZeros)
+```
+
+...will result in `"b=false&i=0"`.
+
 ### Unsupported Values
 
 Values of the following kinds aren't supported and, if present, must be ignored.

encode.go

@@ -67,23 +67,33 @@ func (e Encoder) Encode(dst interface{}) error {
 
 // EncodeToString encodes dst as a form and returns it as a string.
 func EncodeToString(dst interface{}) (string, error) {
+	return EncodeToStringWith(dst, defaultDelimiter, defaultEscape, defaultKeepZeros)
+}
+
+// EncodeToStringWith encodes dst as a form with delimiter d, escape e, keeping zero values if z, and returns it as a string.
+func EncodeToStringWith(dst interface{}, d rune, e rune, z bool) (string, error) {
 	v := reflect.ValueOf(dst)
-	n, err := encodeToNode(v, false)
+	n, err := encodeToNode(v, z)
 	if err != nil {
 		return "", err
 	}
-	vs := n.values(defaultDelimiter, defaultEscape)
+	vs := n.values(d, e)
 	return vs.Encode(), nil
 }
 
 // EncodeToValues encodes dst as a form and returns it as Values.
 func EncodeToValues(dst interface{}) (url.Values, error) {
+	return EncodeToValuesWith(dst, defaultDelimiter, defaultEscape, defaultKeepZeros)
+}
+
+// EncodeToValuesWith encodes dst as a form with delimiter d, escape e, keeping zero values if z, and returns it as Values.
+func EncodeToValuesWith(dst interface{}, d rune, e rune, z bool) (url.Values, error) {
 	v := reflect.ValueOf(dst)
-	n, err := encodeToNode(v, false)
+	n, err := encodeToNode(v, z)
 	if err != nil {
 		return nil, err
 	}
-	vs := n.values(defaultDelimiter, defaultEscape)
+	vs := n.values(d, e)
 	return vs, nil
 }
 

form.go

@@ -11,4 +11,5 @@ const (
 
 	defaultDelimiter = '.'
 	defaultEscape    = '\\'
+	defaultKeepZeros = false
 )