some cleanup and minor fixes...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>

README.md

@@ -864,6 +864,7 @@ require('ig-types/Map')
 Replace key in map retaining item order
 ```bnf
 <map>.replaceKey(<old>, <new>)
+<map>.replaceKey(<old>, <new>, true)
     -> <map>
 ```
 
@@ -913,6 +914,7 @@ require('ig-types/Set')
 Replace value in set with other value retaining item order
 ```bnf
 <set>.replace(<old>, <new>)
+<set>.replace(<old>, <new>, true)
     -> <set>
 ```
 
@@ -930,16 +932,24 @@ Note that when sorting large sets this can get expensive.
 
 Replace item at position in set retaining order
 ```bnf
-<set>.replace(<old>, <new>)
+<set>.replaceAt(<index>, <new>)
+<set>.replaceAt(<index>, <new>, true)
     -> <set>
 ```
 
+If `<index>` is less than `0` the `<new>` item will be prepended to `<set>`,
+if the `<index>` is greater than or equal to `<set>.size` then `<new>` is 
+appended.
+
 Replace the value at index without sorting
 ```bnf
-<set>.replace(<old>, <new>, false)
+<set>.replaceAt(<index>, <new>, false)
     -> <set>
 ```
 
+Here, if `<index>` is less than `0` or greater than or equal to `<set>.size`
+`<new>` will always be appended to `<set>`.
+
 Note that when sorting large sets this can get expensive.
 
 

Set.js

@@ -60,17 +60,33 @@ object.Mixin('SetMixin', 'soft', {
 		ordered
 			&& this.sort(order)
 		return this },
+	// NOTE: if index is <0 then the value is prepended to the set, if 
+	// 		it's >=this.size then the value will be appended.
+	// 		if ordered is set to false in both cases the value is appended.
 	replaceAt: function(index, value, ordered=true){
-		// nothing to do...
-		if(this.size < index || old === value){
+		// append...
+		if(index >= this.size){
+			this.add(value)
 			return this }
-		var order = [...this]
-		var old = order[index]
+		// prepend...
+		if(index < 0){
+			index = 0
+			var order = [, ...this]
+		// replace...
+		} else {
+			var order = [...this]
+			var old = order[index] 
+			// nothing to do...
+			if(old === value){
+				return this } }
 		ordered
 			&& (order[index] = value)
+
 		// replace...
-		this.delete(old)
+		this.has(old)
+			&& this.delete(old)
 		this.add(value)
+
 		ordered
 			&& this.sort(order)
 		return this },

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ig-types",
-  "version": "6.8.0",
+  "version": "6.8.1",
   "description": "Generic JavaScript types and type extensions...",
   "main": "main.js",
   "scripts": {