From f36a4a213c10bd80e6d109f21e2d2cb765adeb58 Mon Sep 17 00:00:00 2001
From: Bo Yao <bo@near.org>
Date: Fri, 20 May 2022 13:55:29 +0800
Subject: [PATCH] add lookup set

---
 src/collections/index.js      |  4 +++-
 src/collections/lookup-set.js | 34 ++++++++++++++++++++++++++++++++++
 src/index.js                  | 10 ++++++++--
 3 files changed, 45 insertions(+), 3 deletions(-)
 create mode 100644 src/collections/lookup-set.js

diff --git a/src/collections/index.js b/src/collections/index.js
index b7ffe51d5..258a34850 100644
--- a/src/collections/index.js
+++ b/src/collections/index.js
@@ -1,7 +1,9 @@
 import { LookupMap } from "./lookup-map";
 import { Vector } from "./vector";
+import { LookupSet } from "./lookup-set";
 
 export {
     LookupMap,
-    Vector
+    Vector,
+    LookupSet
 }
\ No newline at end of file
diff --git a/src/collections/lookup-set.js b/src/collections/lookup-set.js
new file mode 100644
index 000000000..746a5878d
--- /dev/null
+++ b/src/collections/lookup-set.js
@@ -0,0 +1,34 @@
+import * as near from '../api'
+
+export class LookupSet {
+    constructor(keyPrefix) {
+        this.keyPrefix = keyPrefix
+    }
+
+    contains(key) {
+        let storageKey = this.keyPrefix + key
+        return near.jsvmStorageHasKey(storageKey)
+    }
+    
+    remove(key) {
+        let storageKey = this.keyPrefix + key
+        if (near.jsvmStorageRemove(storageKey)) {
+            return near.storageGetEvicted()
+        }
+        return null
+    }
+
+    set(key) {
+        let storageKey = this.keyPrefix + key
+        if (near.jsvmStorageWrite(storageKey, '')) {
+            return near.storageGetEvicted()
+        }
+        return null
+    }
+
+    extend(kvs) {
+        for(let kv of kvs) {
+            this.set(kv[0])
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/index.js b/src/index.js
index 458f2c66f..fd5aa4655 100644
--- a/src/index.js
+++ b/src/index.js
@@ -9,7 +9,11 @@ import {
 } from './near-contract'
 
 import * as near from './api'
-import { LookupMap } from './collections/lookup-map'
+import { 
+    LookupMap,
+    Vector,
+    LookupSet
+} from './collections'
 
 export {
     call,
@@ -17,5 +21,7 @@ export {
     NearBindgen,
     NearContract,
     near,
-    LookupMap
+    LookupMap,
+    Vector,
+    LookupSet
 }
\ No newline at end of file