Add hacks for scala classlib. Add DOM method for convenience. Improve

Scala example

classlib/src/main/java/org/teavm/classlib/impl/JCLPlugin.java

@@ -50,5 +50,6 @@ public class JCLPlugin implements TeaVMPlugin {
         host.add(new MethodReference(LambdaMetafactory.class, "metafactory", MethodHandles.Lookup.class,
                 String.class, MethodType.class, MethodType.class, MethodHandle.class, MethodType.class,
                 CallSite.class), new LambdaMetafactorySubstitutor());
+        host.add(new ScalaHacks());
     }
 }

classlib/src/main/java/org/teavm/classlib/impl/ScalaHacks.java

@@ -0,0 +1,81 @@
+package org.teavm.classlib.impl;
+
+import java.util.List;
+import java.util.Properties;
+import org.teavm.diagnostics.Diagnostics;
+import org.teavm.model.BasicBlock;
+import org.teavm.model.ClassHolder;
+import org.teavm.model.ClassHolderTransformer;
+import org.teavm.model.ClassReaderSource;
+import org.teavm.model.FieldHolder;
+import org.teavm.model.Instruction;
+import org.teavm.model.MethodHolder;
+import org.teavm.model.Program;
+import org.teavm.model.emit.ProgramEmitter;
+import org.teavm.model.instructions.ConstructInstruction;
+import org.teavm.model.instructions.InvokeInstruction;
+import org.teavm.model.instructions.PutFieldInstruction;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class ScalaHacks implements ClassHolderTransformer {
+    private static final String ATTR_NAME_CLASS = "java.util.jar.Attributes$Name";
+    @Override
+    public void transformClass(ClassHolder cls, ClassReaderSource innerSource, Diagnostics diagnostics) {
+        switch (cls.getName()) {
+            case "scala.util.PropertiesTrait$class":
+                transformPropertiesTrait(cls, innerSource);
+                break;
+            case "scala.util.Properties$":
+                transformProperties(cls);
+                break;
+        }
+    }
+
+    private void transformPropertiesTrait(ClassHolder cls, ClassReaderSource innerSource) {
+        for (MethodHolder method : cls.getMethods()) {
+            if (method.getName().equals("scalaProps")) {
+                ProgramEmitter pe = ProgramEmitter.create(method, innerSource);
+                pe.construct(Properties.class).returnValue();
+            }
+        }
+    }
+
+    private void transformProperties(ClassHolder cls) {
+        for (FieldHolder field : cls.getFields().toArray(new FieldHolder[0])) {
+            if (field.getName().equals("ScalaCompilerVersion")) {
+                cls.removeField(field);
+            }
+        }
+        for (MethodHolder method : cls.getMethods().toArray(new MethodHolder[0])) {
+            if (method.getName().equals("ScalaCompilerVersion")) {
+                cls.removeMethod(method);
+            } else if (method.getName().equals("<init>")) {
+                Program program = method.getProgram();
+                for (int i = 0; i < program.basicBlockCount(); ++i) {
+                    BasicBlock block = program.basicBlockAt(i);
+                    List<Instruction> instructions = block.getInstructions();
+                    for (int j = 0; j < instructions.size(); ++j) {
+                        Instruction insn = instructions.get(j);
+                        if (insn instanceof InvokeInstruction) {
+                            if (((InvokeInstruction) insn).getMethod().getClassName().equals(ATTR_NAME_CLASS)) {
+                                instructions.remove(j--);
+                            }
+                        } else if (insn instanceof PutFieldInstruction) {
+                            if (((PutFieldInstruction) insn).getField().getFieldName().equals("ScalaCompilerVersion")) {
+                                instructions.remove(j--);
+                            }
+                        } else if (insn instanceof ConstructInstruction) {
+                            ConstructInstruction cons = (ConstructInstruction) insn;
+                            if (cons.getType().equals(ATTR_NAME_CLASS)) {
+                                cons.setType("java.lang.Object");
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

classlib/src/main/java/org/teavm/classlib/java/util/TProperties.java

@@ -0,0 +1,383 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.classlib.java.util;
+
+import org.teavm.classlib.java.io.TBufferedInputStream;
+import org.teavm.classlib.java.io.TIOException;
+import org.teavm.classlib.java.io.TInputStream;
+import org.teavm.classlib.java.io.TOutputStream;
+import org.teavm.classlib.java.io.TOutputStreamWriter;
+import org.teavm.classlib.java.io.TPrintStream;
+import org.teavm.classlib.java.io.TWriter;
+import org.teavm.classlib.java.lang.TString;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class TProperties extends THashtable<Object, Object> {
+    /**
+     * The default values for keys not found in this {@code Properties}
+     * instance.
+     */
+    protected TProperties defaults;
+
+    private static final int NONE = 0, SLASH = 1, UNICODE = 2, CONTINUE = 3,  KEY_DONE = 4, IGNORE = 5;
+
+    public TProperties() {
+        super();
+    }
+
+    public TProperties(TProperties properties) {
+        defaults = properties;
+    }
+
+    private void dumpString(StringBuilder buffer, String string, boolean isKey) {
+        int index = 0, length = string.length();
+        if (!isKey && index < length && string.charAt(index) == ' ') {
+            buffer.append("\\ "); //$NON-NLS-1$
+            index++;
+        }
+
+        for (; index < length; index++) {
+            char ch = string.charAt(index);
+            switch (ch) {
+            case '\t':
+                buffer.append("\\t");
+                break;
+            case '\n':
+                buffer.append("\\n");
+                break;
+            case '\f':
+                buffer.append("\\f");
+                break;
+            case '\r':
+                buffer.append("\\r");
+                break;
+            default:
+                if ("\\#!=:".indexOf(ch) >= 0 || (isKey && ch == ' ')) {
+                    buffer.append('\\');
+                }
+                if (ch >= ' ' && ch <= '~') {
+                    buffer.append(ch);
+                } else {
+                    buffer.append(toHexaDecimal(ch));
+                }
+            }
+        }
+    }
+
+    private char[] toHexaDecimal(final int ch) {
+        char[] hexChars = { '\\', 'u', '0', '0', '0', '0' };
+        int hexChar, index = hexChars.length, copyOfCh = ch;
+        do {
+            hexChar = copyOfCh & 15;
+            if (hexChar > 9) {
+                hexChar = hexChar - 10 + 'A';
+            } else {
+                hexChar += '0';
+            }
+            hexChars[--index] = (char) hexChar;
+        } while ((copyOfCh >>>= 4) != 0);
+        return hexChars;
+    }
+
+    public String getProperty(String name) {
+        Object result = super.get(name);
+        String property = result instanceof String ? (String) result : null;
+        if (property == null && defaults != null) {
+            property = defaults.getProperty(name);
+        }
+        return property;
+    }
+
+    public String getProperty(String name, String defaultValue) {
+        Object result = super.get(name);
+        String property = result instanceof String ? (String) result : null;
+        if (property == null && defaults != null) {
+            property = defaults.getProperty(name);
+        }
+        if (property == null) {
+            return defaultValue;
+        }
+        return property;
+    }
+
+    public void list(TPrintStream out) {
+        if (out == null) {
+            throw new NullPointerException();
+        }
+        StringBuilder buffer = new StringBuilder(80);
+        TEnumeration<?> keys = propertyNames();
+        while (keys.hasMoreElements()) {
+            String key = (String) keys.nextElement();
+            buffer.append(key);
+            buffer.append('=');
+            String property = (String) super.get(key);
+            TProperties def = defaults;
+            while (property == null) {
+                property = (String) def.get(key);
+                def = def.defaults;
+            }
+            if (property.length() > 40) {
+                buffer.append(property.substring(0, 37));
+                buffer.append("..."); //$NON-NLS-1$
+            } else {
+                buffer.append(property);
+            }
+            out.println(TString.wrap(buffer.toString()));
+            buffer.setLength(0);
+        }
+    }
+
+    @SuppressWarnings("fallthrough")
+    public synchronized void load(TInputStream in) throws TIOException {
+        if (in == null) {
+            throw new NullPointerException();
+        }
+        int mode = NONE, unicode = 0, count = 0;
+        char nextChar, buf[] = new char[40];
+        int offset = 0, keyLength = -1, intVal;
+        boolean firstChar = true;
+        TBufferedInputStream bis = new TBufferedInputStream(in);
+
+        while (true) {
+            intVal = bis.read();
+            if (intVal == -1) {
+                // if mode is UNICODE but has less than 4 hex digits, should
+                // throw an IllegalArgumentException
+                if (mode == UNICODE && count < 4) {
+                    throw new IllegalArgumentException("Invalid Unicode sequence: expected format \\uxxxx");
+                }
+                // if mode is SLASH and no data is read, should append '\u0000'
+                // to buf
+                if (mode == SLASH) {
+                    buf[offset++] = '\u0000';
+                }
+                break;
+            }
+            nextChar = (char) (intVal & 0xff);
+
+            if (offset == buf.length) {
+                char[] newBuf = new char[buf.length * 2];
+                System.arraycopy(buf, 0, newBuf, 0, offset);
+                buf = newBuf;
+            }
+            if (mode == UNICODE) {
+                int digit = Character.digit(nextChar, 16);
+                if (digit >= 0) {
+                    unicode = (unicode << 4) + digit;
+                    if (++count < 4) {
+                        continue;
+                    }
+                } else if (count <= 4) {
+                    throw new IllegalArgumentException("Invalid Unicode sequence: illegal character");
+                }
+                mode = NONE;
+                buf[offset++] = (char) unicode;
+                if (nextChar != '\n') {
+                    continue;
+                }
+            }
+            if (mode == SLASH) {
+                mode = NONE;
+                switch (nextChar) {
+                case '\r':
+                    mode = CONTINUE; // Look for a following \n
+                    continue;
+                case '\n':
+                    mode = IGNORE; // Ignore whitespace on the next line
+                    continue;
+                case 'b':
+                    nextChar = '\b';
+                    break;
+                case 'f':
+                    nextChar = '\f';
+                    break;
+                case 'n':
+                    nextChar = '\n';
+                    break;
+                case 'r':
+                    nextChar = '\r';
+                    break;
+                case 't':
+                    nextChar = '\t';
+                    break;
+                case 'u':
+                    mode = UNICODE;
+                    unicode = count = 0;
+                    continue;
+                }
+            } else {
+                switch (nextChar) {
+                case '#':
+                case '!':
+                    if (firstChar) {
+                        while (true) {
+                            intVal = bis.read();
+                            if (intVal == -1) {
+                                break;
+                            }
+                            // & 0xff not required
+                            nextChar = (char) intVal;
+                            if (nextChar == '\r' || nextChar == '\n') {
+                                break;
+                            }
+                        }
+                        continue;
+                    }
+                    break;
+                case '\n':
+                    if (mode == CONTINUE) { // Part of a \r\n sequence
+                        mode = IGNORE; // Ignore whitespace on the next line
+                        continue;
+                    }
+                    // fall into the next case
+                case '\r':
+                    mode = NONE;
+                    firstChar = true;
+                    if (offset > 0 || (offset == 0 && keyLength == 0)) {
+                        if (keyLength == -1) {
+                            keyLength = offset;
+                        }
+                        String temp = new String(buf, 0, offset);
+                        put(temp.substring(0, keyLength), temp
+                                .substring(keyLength));
+                    }
+                    keyLength = -1;
+                    offset = 0;
+                    continue;
+                case '\\':
+                    if (mode == KEY_DONE) {
+                        keyLength = offset;
+                    }
+                    mode = SLASH;
+                    continue;
+                case ':':
+                case '=':
+                    if (keyLength == -1) { // if parsing the key
+                        mode = NONE;
+                        keyLength = offset;
+                        continue;
+                    }
+                    break;
+                }
+                if (nextChar < 256 && Character.isWhitespace(nextChar)) {
+                    if (mode == CONTINUE) {
+                        mode = IGNORE;
+                    }
+                    // if key length == 0 or value length == 0
+                    if (offset == 0 || offset == keyLength || mode == IGNORE) {
+                        continue;
+                    }
+                    if (keyLength == -1) { // if parsing the key
+                        mode = KEY_DONE;
+                        continue;
+                    }
+                }
+                if (mode == IGNORE || mode == CONTINUE) {
+                    mode = NONE;
+                }
+            }
+            firstChar = false;
+            if (mode == KEY_DONE) {
+                keyLength = offset;
+                mode = NONE;
+            }
+            buf[offset++] = nextChar;
+        }
+        if (keyLength == -1 && offset > 0) {
+            keyLength = offset;
+        }
+        if (keyLength >= 0) {
+            String temp = new String(buf, 0, offset);
+            put(temp.substring(0, keyLength), temp.substring(keyLength));
+        }
+    }
+
+    public TEnumeration<?> propertyNames() {
+        THashtable<Object, Object> selected = new THashtable<>();
+        selectProperties(selected);
+        return selected.keys();
+    }
+
+    private void selectProperties(THashtable<Object, Object> selected) {
+        if(defaults != null) {
+            defaults.selectProperties(selected);
+        }
+        selected.putAll(this);
+    }
+
+    @Deprecated
+    public void save(TOutputStream out, String comment) {
+        try {
+            store(out, comment);
+        } catch (TIOException e) {
+        }
+    }
+
+    public Object setProperty(String name, String value) {
+        return put(name, value);
+    }
+
+    public synchronized void store(TOutputStream out, String comments) throws TIOException {
+        TOutputStreamWriter writer = new TOutputStreamWriter(out, "ISO8859_1");
+        if (comments != null) {
+            writeComments(writer, comments);
+        }
+        writer.write('#');
+        writer.write(new TDate().toString());
+        writer.write("\n");
+
+        StringBuilder buffer = new StringBuilder(200);
+        for (TIterator<TMap.Entry<Object, Object>> iter = entrySet().iterator(); iter.hasNext();) {
+            TMap.Entry<Object, Object> entry = iter.next();
+            String key = (String) entry.getKey();
+            dumpString(buffer, key, true);
+            buffer.append('=');
+            dumpString(buffer, (String) entry.getValue(), false);
+            buffer.append("\n");
+            writer.write(buffer.toString());
+            buffer.setLength(0);
+        }
+        writer.flush();
+    }
+
+    private void writeComments(TWriter writer, String comments) throws TIOException {
+        writer.write('#');
+        char[] chars = comments.toCharArray();
+        for (int index = 0; index < chars.length; index++) {
+            if (chars[index] == '\r' || chars[index] == '\n') {
+                int indexPlusOne = index + 1;
+                if (chars[index] == '\r' && indexPlusOne < chars.length
+                        && chars[indexPlusOne] == '\n') {
+                    // "\r\n"
+                    continue;
+                }
+                writer.write("\n");
+                if (indexPlusOne < chars.length
+                        && (chars[indexPlusOne] == '#' || chars[indexPlusOne] == '!')) {
+                    // return char with either '#' or '!' afterward
+                    continue;
+                }
+                writer.write('#');
+            } else {
+                writer.write(chars[index]);
+            }
+        }
+        writer.write("\n");
+    }
+}

jso/apis/src/main/java/org/teavm/jso/dom/html/HTMLDocument.java

@@ -15,6 +15,7 @@
  */
 package org.teavm.jso.dom.html;
 
+import java.util.function.Consumer;
 import org.teavm.jso.JSProperty;
 import org.teavm.jso.browser.Window;
 import org.teavm.jso.dom.events.EventTarget;
@@ -32,6 +33,12 @@ public interface HTMLDocument extends Document, EventTarget {
     @Override
     HTMLElement createElement(String tagName);
 
+    default HTMLElement createElement(String tagName, Consumer<HTMLElement> consumer) {
+        HTMLElement result = createElement(tagName);
+        consumer.accept(result);
+        return result;
+    }
+
     @Override
     HTMLElement getElementById(String elementId);
 

jso/apis/src/main/java/org/teavm/jso/dom/html/HTMLElement.java

@@ -15,6 +15,7 @@
  */
 package org.teavm.jso.dom.html;
 
+import java.util.function.Consumer;
 import org.teavm.jso.JSProperty;
 import org.teavm.jso.dom.css.ElementCSSInlineStyle;
 import org.teavm.jso.dom.events.EventTarget;
@@ -110,4 +111,34 @@ public interface HTMLElement extends Element, ElementCSSInlineStyle, EventTarget
     void setInnerHTML(String content);
 
     TextRectangle getBoundingClientRect();
+
+    default HTMLElement withAttr(String name, String value) {
+        setAttribute(name, value);
+        return this;
+    }
+
+    default HTMLElement withChild(String tagName) {
+        HTMLElement result = getOwnerDocument().createElement(tagName);
+        appendChild(result);
+        return result;
+    }
+
+    default HTMLElement withChild(String tagName, Consumer<HTMLElement> consumer) {
+        HTMLElement result = getOwnerDocument().createElement(tagName);
+        appendChild(result);
+        consumer.accept(result);
+        return result;
+    }
+
+    default HTMLElement clear() {
+        while (getLastChild() != null) {
+            removeChild(getLastChild());
+        }
+        return this;
+    }
+
+    default HTMLElement withText(String content) {
+        clear().appendChild(getOwnerDocument().createTextNode(content));
+        return this;
+    }
 }

jso/apis/src/main/java/org/teavm/jso/dom/xml/Node.java

@@ -103,4 +103,10 @@ public interface Node extends JSObject {
 
     @JSProperty
     Document getOwnerDocument();
+
+    default void delete() {
+        if (getParentNode() != null) {
+            getParentNode().removeChild(this);
+        }
+    }
 }

samples/scala/src/main/scala/org/teavm/samples/scala/Calculator.scala

@@ -0,0 +1,59 @@
+package org.teavm.samples.scala
+
+import org.teavm.samples.scala.Grammar._
+
+object Calculator {
+  def eval(expr : Expr) : BigInt = expr match {
+    case Add(a, b) => eval(a) + eval(b)
+    case Subtract(a, b) => eval(a) - eval(b)
+    case Multiply(a, b) => eval(a) * eval(b)
+    case Divide(a, b) => eval(a) * eval(b)
+    case Negate(n) => -eval(n)
+    case Number(v) => v
+  }
+
+  def print(expr : Expr) : String = expr match {
+    case Add(a, b) => "(" + print(a) + " + " + print(b) + ")"
+    case Subtract(a, b) => "(" + print(a) + " - " + print(b) + ")"
+    case Multiply(a, b) => "(" + print(a) + " * " + print(b) + ")"
+    case Divide(a, b) => "(" + print(a) + " / " + print(b) + ")"
+    case Negate(n) => "-" + print(n)
+    case Number(v) => v.toString()
+  }
+
+  def parse(str : Seq[Char]) = additive.parse(str)
+
+  def additive = multiplicative ~ ((keyword("+") | keyword("-")) ~ multiplicative).* >> {
+    case (h, t) => t.foldLeft(h) {
+      case (left, ("+", right)) => Add(left, right)
+      case (left, ("-", right)) => Subtract(left, right)
+    }
+  }
+  def multiplicative = unary ~ ((keyword("*") | keyword("/")) ~ unary).* >> {
+    case (h, t) => t.foldLeft(h) {
+      case (left, ("*", right)) => Multiply(left, right)
+      case (left, ("/", right)) => Divide(left, right)
+    }
+  }
+  def unary : Rule[Expr] = keyword("-").? ~ primitive >> {
+    case (Some(_), v) => Negate(v)
+    case (None, v) => v
+  }
+  def primitive : Rule[Expr] = Rule.firstOf(number >> Number, group)
+  def group : Rule[Expr] = keyword("(") ~ additive ~ keyword(")") >> { case ((_, result), _) => result }
+
+  def number : Rule[Int] = range('1', '9') ~ range('0', '9').* ~ ws >> {
+    case ((h, t), _) => t.foldLeft(h - '0')((n, c) => n * 10 + (c - '0'))
+  }
+
+  def keyword(str : String) = s(str) ~ ws >> { case (s, _) => s }
+  def ws = s(" ").* >> { case _ => Unit }
+}
+
+sealed abstract class Expr
+case class Number(value : Int) extends Expr
+case class Add(left : Expr, right : Expr) extends Expr
+case class Subtract(left : Expr, right : Expr) extends Expr
+case class Multiply(left : Expr, right : Expr) extends Expr
+case class Divide(left : Expr, right : Expr) extends Expr
+case class Negate(argument : Expr) extends Expr

samples/scala/src/main/scala/org/teavm/samples/scala/Client.scala

@@ -1,86 +1,30 @@
 package org.teavm.samples.scala
 
+import org.teavm.samples.scala.DOM._
+import org.teavm.samples.scala.Calculator.parse
+import org.teavm.samples.scala.Calculator.print
+import org.teavm.samples.scala.Calculator.eval
 import org.teavm.jso.browser.Window
 import org.teavm.jso.dom.html._
 import org.teavm.jso.dom.events._
 
-object Client extends Grammar {
+object Client {
   def main(args: Array[String]) {
-    var document = HTMLDocument.current
+    var doc = HTMLDocument.current
-    var exprElem = document.getElementById("expr").asInstanceOf[HTMLInputElement]
+    var exprElem = doc.getElementById("expr").asInstanceOf[HTMLInputElement]
-    var calcElem = document.getElementById("calculate")
+    var calcElem = doc.getElementById("calculate")
-    var resultList = document.getElementById("result-list");
+    var resultList = doc.getElementById("result-list");
-    calcElem.addEventListener("click", new EventListener[MouseEvent]() {
+    calcElem.addEventListener("click", (e : MouseEvent) => {
-      def handleEvent(e : MouseEvent) {
+       parse(exprElem.getValue().toSeq) match {
-         additive.parse(exprElem.getValue().toSeq) match {
          case (None, _) => Window.alert("Error parsing expression");
          case (Some(x), Nil) => {
-             val resultElem = document.createElement("div")
+           resultList.insertBefore(doc.createElement("div", (elem : HTMLElement) => {
-             var exprSpan = document.createElement("span");
+             elem.withChild("span").withAttr("class", "plan").withText(print(x) + " = ")
-             exprSpan.setAttribute("class", "plan")
+             elem.withChild("span").withAttr("class", "result").withText(eval(x).toString)
-             exprSpan.appendChild(document.createTextNode(print(x) + " = "))
+           }), resultList.getFirstChild)
-             var resultSpan = document.createElement("span")
-             resultSpan.setAttribute("class", "result")
-             resultSpan.appendChild(document.createTextNode(eval(x).toString()))
-             resultElem.appendChild(exprSpan)
-             resultElem.appendChild(resultSpan)
-             resultList.insertBefore(resultElem, resultList.getFirstChild)
          }
          case (_, err) => Window.alert("Error parsing expression: " + err);
        }
-      }
     })
   }
-
-  def eval(expr : Expr) : BigInt = expr match {
-    case Add(a, b) => eval(a) + eval(b)
-    case Subtract(a, b) => eval(a) - eval(b)
-    case Multiply(a, b) => eval(a) * eval(b)
-    case Divide(a, b) => eval(a) * eval(b)
-    case Negate(n) => -eval(n)
-    case Number(v) => v
 }
-
-  def print(expr : Expr) : String = expr match {
-    case Add(a, b) => "(" + print(a) + " + " + print(b) + ")"
-    case Subtract(a, b) => "(" + print(a) + " - " + print(b) + ")"
-    case Multiply(a, b) => "(" + print(a) + " * " + print(b) + ")"
-    case Divide(a, b) => "(" + print(a) + " / " + print(b) + ")"
-    case Negate(n) => "-" + print(n)
-    case Number(v) => v.toString()
-  }
-
-  def additive = multiplicative ~ ((keyword("+") | keyword("-")) ~ multiplicative).* >> {
-    case (h, t) => t.foldLeft(h) {
-      case (left, ("+", right)) => Add(left, right)
-      case (left, ("-", right)) => Subtract(left, right)
-    }
-  }
-  def multiplicative = primitive ~ ((keyword("*") | keyword("/")) ~ primitive).* >> {
-    case (h, t) => t.foldLeft(h) {
-      case (left, ("*", right)) => Multiply(left, right)
-      case (left, ("/", right)) => Divide(left, right)
-    }
-  }
-  def unary : Rule[Expr] = keyword("-").? ~ primitive >> {
-    case (Some(_), v) => Negate(v)
-    case (None, v) => v
-  }
-  def primitive : Rule[Expr] = Rule.firstOf(number >> Number, group)
-  def group : Rule[Expr] = keyword("(") ~ additive ~ keyword(")") >> { case ((_, result), _) => result }
-
-  def number : Rule[Int] = range('1', '9') ~ range('0', '9').* ~ ws >> {
-    case ((h, t), _) => t.foldLeft(h - '0')((n, c) => n * 10 + (c - '0'))
-  }
-
-  def keyword(str : String) = s(str) ~ ws >> { case (s, _) => s }
-  def ws = s(" ").* >> { case _ => Unit }
-}
-
-sealed abstract class Expr
-case class Number(value : Int) extends Expr
-case class Add(left : Expr, right : Expr) extends Expr
-case class Subtract(left : Expr, right : Expr) extends Expr
-case class Multiply(left : Expr, right : Expr) extends Expr
-case class Divide(left : Expr, right : Expr) extends Expr
-case class Negate(argument : Expr) extends Expr

samples/scala/src/main/scala/org/teavm/samples/scala/DOM.scala

@@ -0,0 +1,18 @@
+package org.teavm.samples.scala
+
+import org.teavm.jso.dom.events._
+import java.util.function.Consumer
+
+object DOM {
+  implicit def toEventListener[T <: Event](f : T => Any) : EventListener[T] = {
+    new EventListener[T]() {
+      def handleEvent(e : T) = f(e)
+    }
+  }
+
+  implicit def toConsumer[T](f : T => Any) : Consumer[T] = {
+    new Consumer[T]() {
+      def accept(e : T) = f(e)
+    }
+  }
+}

samples/scala/src/main/scala/org/teavm/samples/scala/Grammar.scala

@@ -1,6 +1,6 @@
 package org.teavm.samples.scala
 
-trait Grammar {
+object Grammar {
   def rule[T](f : Seq[Char] => (Option[T], Seq[Char])) : Rule[T] = Rule.rule(f)
   def s(str : String) : Rule[String] = Rule.expect(str)
   def range(first : Char, last : Char) : Rule[Char] = Rule.range(first, last)
@@ -23,21 +23,16 @@ trait Rule[T] {
 }
 
 object Rule {
-  def rule[T](f : Seq[Char] => (Option[T], Seq[Char])) : Rule[T] = {
+  def rule[T](f : Seq[Char] => (Option[T], Seq[Char])) : Rule[T] = new Rule[T]() {
-    new Rule[T]() {
     def parse(chars : Seq[Char]) : (Option[T], Seq[Char]) = f(chars)
   }
-  }
   def concat[S, T](left : Rule[S], right : => Rule[T]) : Rule[(S, T)] = {
-    lazy val right2 = right
+    rule(chars => left.parse(chars) match {
-    rule(chars => {
+      case (Some(leftResult), rem) => right.parse(rem) match {
-      left.parse(chars) match {
-        case (Some(leftResult), rem) => right2.parse(rem) match {
         case (Some(rightResult), rem2) => (Some((leftResult, rightResult)), rem2)
         case (None, rem2) => (None, rem)
       }
       case (None, rem) => (None, rem)
-      }
     })
   }
   def unlimited[T](inner : Rule[T]) : Rule[List[T]] = {
@@ -56,24 +51,19 @@ object Rule {
     })
   }
   def firstOf[T](first : Rule[T], second : => Rule[T]) : Rule[T] = {
-    lazy val second2 = second
+    rule(chars => first.parse(chars) match {
-    rule(chars => {
-      first.parse(chars) match {
       case (Some(result), rem) => (Some(result), rem)
-        case (None, _) => second2.parse(chars) match {
+      case (None, _) => second.parse(chars) match {
         case (Some(result), rem) => (Some(result), rem)
         case (None, _) => (None, chars)
       }
-      }
     })
   }
   def optional[T](inner : Rule[T]) : Rule[Option[T]] = {
-    rule {
+    rule(chars => inner.parse(chars) match {
-      chars => inner.parse(chars) match {
       case (Some(result), rem) => (Some(Some(result)), rem)
       case (None, rem) => (Some(None), chars)
-      }
+    })
-    }
   }
   implicit def expect(str : String) : Rule[String] = {
     def iter(chars : Seq[Char], index : Int) : (Boolean, Seq[Char]) = {
@@ -94,19 +84,15 @@ object Rule {
     })
   }
   def andThen[T, S](inner : Rule[T], f : T => S) : Rule[S] = {
-    rule(chars => {
+    rule(chars => inner.parse(chars) match {
-      inner.parse(chars) match {
       case (Some(result), rem) => (Some(f(result)), rem)
       case (None, rem) => (None, rem)
-      }
     })
   }
   def range(first : Char, last : Char) : Rule[Char] = {
-    rule(chars => {
+    rule(chars => chars match {
-      chars match {
       case c +: rem if c >= first && c <= last => (Some(c), rem)
       case _ => (None, chars)
-      }
     })
   }
 }