From b677355c0fd8b71bd4586b2f7548d6b8ed68615b Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Fri, 18 Jan 2019 17:48:12 +0100
Subject: [PATCH] Convert ValueTypeParser to an Iterator

---
 .../jwebassembly/module/ModuleGenerator.java     |  5 +++--
 .../jwebassembly/module/WasmCallInstruction.java |  9 +++++----
 .../jwebassembly/wasm/ValueTypeParser.java       | 16 +++++++++++++---
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java b/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java
index ceb1626..16b17fa 100644
--- a/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java
+++ b/src/de/inetsoftware/jwebassembly/module/ModuleGenerator.java
@@ -20,6 +20,7 @@ import java.io.InputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
@@ -354,10 +355,10 @@ public class ModuleGenerator {
         if( !isStatic ) {
             writer.writeMethodParam( "param", ValueType.anyref, "this" );
         }
-        ValueTypeParser parser = new ValueTypeParser( signature );
+        Iterator<AnyType> parser = new ValueTypeParser( signature );
         AnyType type;
         for( String kind : new String[] {"param","result"}) {
-            while( (type = parser.next()) != null ) {
+            while( parser.hasNext() && (type = parser.next()) != null ) {
                 String paramName = null;
                 if( kind == "param" ) {
                     if( variables != null ) {
diff --git a/src/de/inetsoftware/jwebassembly/module/WasmCallInstruction.java b/src/de/inetsoftware/jwebassembly/module/WasmCallInstruction.java
index 0781c12..68d0db4 100644
--- a/src/de/inetsoftware/jwebassembly/module/WasmCallInstruction.java
+++ b/src/de/inetsoftware/jwebassembly/module/WasmCallInstruction.java
@@ -17,10 +17,12 @@
 package de.inetsoftware.jwebassembly.module;
 
 import java.io.IOException;
+import java.util.Iterator;
 
 import javax.annotation.Nonnull;
 
 import de.inetsoftware.classparser.Member;
+import de.inetsoftware.jwebassembly.wasm.AnyType;
 import de.inetsoftware.jwebassembly.wasm.ValueType;
 import de.inetsoftware.jwebassembly.wasm.ValueTypeParser;
 
@@ -103,15 +105,14 @@ class WasmCallInstruction extends WasmInstruction {
         if( paramCount >= 0 ) {
             return;
         }
-        ValueTypeParser parser = new ValueTypeParser( method.getType() );
+        Iterator<AnyType> parser = new ValueTypeParser( method.getType() );
         paramCount = 0;
         while( parser.next() != null ) {
             paramCount++;
         }
         valueType = (ValueType)parser.next();
-        ValueType type;
-        while( (type = (ValueType)parser.next()) != null ) {
-            valueType = type;
+        while( parser.hasNext() ) {
+            valueType = (ValueType)parser.next();
             paramCount--;
         }
     }
diff --git a/src/de/inetsoftware/jwebassembly/wasm/ValueTypeParser.java b/src/de/inetsoftware/jwebassembly/wasm/ValueTypeParser.java
index 178b4dd..e32c1d0 100644
--- a/src/de/inetsoftware/jwebassembly/wasm/ValueTypeParser.java
+++ b/src/de/inetsoftware/jwebassembly/wasm/ValueTypeParser.java
@@ -15,6 +15,9 @@
  */
 package de.inetsoftware.jwebassembly.wasm;
 
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
 import de.inetsoftware.jwebassembly.WasmException;
 import de.inetsoftware.jwebassembly.module.TypeManager;
 
@@ -23,7 +26,7 @@ import de.inetsoftware.jwebassembly.module.TypeManager;
  * 
  * @author Volker Berlin
  */
-public class ValueTypeParser {
+public class ValueTypeParser implements Iterator<AnyType> {
     private final String sig;
 
     private int          idx;
@@ -56,14 +59,21 @@ public class ValueTypeParser {
         }
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public boolean hasNext() {
+        return idx < sig.length();
+    }
+
     /**
      * Get the next value in the signature or null if the parameter are end or the signature is end.
      * 
      * @return next type or null
      */
     public AnyType next() {
-        if( idx >= sig.length() ) {
-            return null;
+        if( !hasNext() ) {
+            throw new NoSuchElementException();
         }
         switch( sig.charAt( idx++ ) ) {
             case ')':