Add ssv.meet method (#35)

README.md

@@ -36,6 +36,9 @@ ssv.diff("mark tom tom", "mark matt") // "tom tom"
 ssv.diff("matt matt matt", "") // "matt matt matt"
 ssv.diff("mark mark", "tom tom") // "mark mark"
 ssv.diff("mark tom tom tom", "tom") // "mark"
+ssv.meet("", "mark") // ""
+ssv.meet("mark matt travis", "tom scott") // ""
+ssv.meet("mark tom tom", "mark tom travis") // "mark tom"
 ssv.union("mark tom ", "travis tom") // "mark tom travis"
 ssv.union("mark tom tom", "travis tom") // "mark tom travis"
 ssv.union("matt mark", "matt") // "matt mark"
@@ -71,6 +74,10 @@ ssv.xor("mark mark", "tom tom") // "mark tom"
 - Get the difference of 2 SSV strings (values in first not present in second)
 - `@return` string
 
+### `ssv.meet(SSV, SSV2)`
+- Get the intersection of 2 SSV strings (unique values present in both)
+- `@return` string
+
 ### `ssv.split(SSV)`
 - Split <var>SSV</var> into compact array of values
 - `@return` array

ssv.d.ts

@@ -4,6 +4,7 @@ declare module ssv {
   export function compact(ssv: string): string;
   export function concat(ssv: string, more: string): string;
   export function diff(ssv: string, less: string): string;
+  export function meet(left: string, right: string): string;
   export function split(ssv: string): string[];
   export function union(ssv: string, more: string): string;
   export function uniq(ssv: string): string;

ssv.js

@@ -56,6 +56,10 @@
     return union(diff(left, right), diff(right, left))
   }
 
+  function meet(left, right) {
+    return diff(union(left, right), xor(left, right))
+  }
+
   function uniq(ssv) {
     ssv = split(ssv)
     var u = []
@@ -91,6 +95,7 @@
   api["compact"] = compact
   api["concat"] = concat
   api["diff"] = diff
+  api["meet"] = meet
   api["split"] = split
   api["union"] = union
   api["uniq"] = uniq

test.js

@@ -68,6 +68,13 @@ assert.strictEqual(api.union("mark mark mark", ""), "mark")
 assert.strictEqual(api.union("mark mark mark", "tom"), "mark tom")
 console.log("#union tests passed")
 
+assert.strictEqual(api.meet("", ""), "")
+assert.strictEqual(api.meet("", "mark"), "")
+assert.strictEqual(api.meet("mark matt travis", "tom scott"), "")
+assert.strictEqual(api.meet("mark tom tom", "mark tom travis"), "mark tom")
+assert.strictEqual(api.meet("tom tom tom scott", "tom travis scott"), "tom scott")
+console.log("#meet tests passed")
+
 assert.strictEqual(api.diff("", ""), "")
 assert.strictEqual(api.diff("", "mark"), "")
 assert.strictEqual(api.diff("mark tom", "travis"), "mark tom")