From 8d8351deaf51a98363010536d193709fefde8351 Mon Sep 17 00:00:00 2001
From: sal <m6567fc@outlook.com>
Date: Sun, 28 Nov 2021 19:53:14 +0800
Subject: [PATCH] Update README.md

---
 README.md | 46 +++++++++++++++++++++-------------------------
 1 file changed, 21 insertions(+), 25 deletions(-)

diff --git a/README.md b/README.md
index 94665d8..ef59977 100644
--- a/README.md
+++ b/README.md
@@ -22,30 +22,23 @@ package com.github.salpadding.wasmer.example;
 
 
 import com.github.salpadding.wasmer.*;
-import kotlin.Pair;
-import org.jetbrains.annotations.NotNull;
 
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
-// a host function example
+
 class MemoryPeek implements HostFunction {
-    @NotNull
     @Override
-    // name of host function
     public String getName() {
         return "__peek";
     }
 
-    @NotNull
     @Override
-    // args are aligned to long 
-    public long[] execute(@NotNull Instance inst, @NotNull long[] args) {
+    public long[] execute(Instance inst, long[] args) {
         int off = (int) args[0];
         int len = (int) args[1];
 
-        // read data from memory
         byte[] data = inst.getMemory("memory").read(off, len);
 
         for (byte b : data) {
@@ -53,49 +46,51 @@ class MemoryPeek implements HostFunction {
         }
 
         System.out.println();
-        return HostFunction.getEmptyLongs();
+        return Instance.EMPTY_LONGS;
+    }
+
+    @Override
+    public List<ValType> getParams() {
+        return Arrays.asList(ValType.I32, ValType.I32);
     }
 
-    @NotNull
     @Override
-    public Pair<List<ValType>, List<ValType>> getSignature() {
-        return new Pair<>(
-                Arrays.asList(ValType.I32, ValType.I32),
-                Collections.emptyList()
-        );
+    public List<ValType> getRet() {
+        return Collections.emptyList();
     }
 }
 
 class EmptyHost implements HostFunction {
-    private String name;
+    private final String name;
 
     public EmptyHost(String name) {
         this.name = name;
     }
 
-    @NotNull
     @Override
     public String getName() {
         return name;
     }
 
-    @NotNull
     @Override
-    public long[] execute(@NotNull Instance inst, @NotNull long[] args) {
+    public long[] execute(Instance inst, long[] args) {
         System.out.println("empty host function executed");
-        return HostFunction.getEmptyLongs();
+        return EMPTY_LONGS;
     }
 
-    @NotNull
     @Override
-    public Pair<List<ValType>, List<ValType>> getSignature() {
-        return new Pair<>(Collections.singletonList(ValType.I64), Collections.emptyList());
+    public List<ValType> getParams() {
+        return Collections.singletonList(ValType.I64);
+    }
+
+    @Override
+    public List<ValType> getRet() {
+        return Collections.emptyList();
     }
 }
 
 public class Example {
     public static void main(String[] args) {
-        // initialize Native class
         Natives.initialize(1024);
         byte[] bin = TestUtil.readClassPathFile("testdata/wasm.wasm");
         Instance ins = Instance.create(bin, Options.empty(), Arrays.asList(new EmptyHost("alert"), new MemoryPeek()));
@@ -113,4 +108,5 @@ public class Example {
         }
     }
 }
+
 ```
\ No newline at end of file