adding support for exposing builtins

dynjs/src/main/java/org/dynjs/runtime/DynJS.java

@@ -24,24 +24,25 @@
 import org.antlr.runtime.tree.CommonTree;
 import org.antlr.runtime.tree.CommonTreeNodeStream;
 import org.dynjs.api.Function;
+import org.dynjs.api.Scope;
 import org.dynjs.compiler.DynJSCompiler;
 import org.dynjs.exception.SyntaxError;
-import org.dynjs.parser.ES3Lexer;
-import org.dynjs.parser.ES3Parser;
-import org.dynjs.parser.ES3Walker;
-import org.dynjs.parser.Executor;
-import org.dynjs.parser.Statement;
+import org.dynjs.parser.*;
+import org.dynjs.runtime.loader.Builtin;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;
+import java.util.Set;
 
 public class DynJS {
 
     private final DynJSCompiler compiler;
+    private final DynJSConfig config;
 
     public DynJS(DynJSConfig config) {
-        compiler = new DynJSCompiler(config);
+        this.config = config;
+        compiler = new DynJSCompiler(this.config);
     }
 
     public void eval(DynThreadContext context, String expression) {
@@ -90,10 +91,19 @@ private List<Statement> parseSourceCode(DynThreadContext context, ES3Lexer lexer
 
     private void execute(DynThreadContext context, List<Statement> result) {
         Script script = compiler.compile(result.toArray(new Statement[]{}));
-        script.setGlobalScope(context.getScope());
+        Scope globalScope = context.getScope();
+        initBuiltins(globalScope);
+        script.setGlobalScope(globalScope);
         script.execute(context);
     }
 
+    private void initBuiltins(Scope globalScope) {
+        Set<Builtin> builtins = config.getBuiltins();
+        for (Builtin builtin : builtins) {
+            globalScope.define(builtin.getBindingName(), builtin.getBoundObject());
+        }
+    }
+
     public Function compile(CodeBlock codeBlock, final String[] args) {
         return this.compiler.compile(new DynFunction(codeBlock) {
             public String[] getArguments() {

dynjs/src/main/java/org/dynjs/runtime/DynJSConfig.java

@@ -16,9 +16,15 @@
  */
 package org.dynjs.runtime;
 
+import org.dynjs.runtime.loader.Builtin;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+
 public class DynJSConfig {
 
     private boolean debug;
+    private Set<Builtin> builtins = new LinkedHashSet<>();
 
     public void enableDebug() {
         this.debug = true;
@@ -28,4 +34,11 @@ public boolean isDebug() {
         return debug;
     }
 
+    public void addBuiltin(String bindingName, Object boundObject) {
+        builtins.add(new Builtin(bindingName, boundObject));
+    }
+
+    public Set<Builtin> getBuiltins() {
+        return builtins;
+    }
 }

dynjs/src/main/java/org/dynjs/runtime/loader/Builtin.java

@@ -0,0 +1,20 @@
+package org.dynjs.runtime.loader;
+
+public class Builtin {
+
+    private final String bindingName;
+    private final Object boundObject;
+
+    public Builtin(String bindingName, Object boundObject) {
+        this.bindingName = bindingName;
+        this.boundObject = boundObject;
+    }
+
+    public String getBindingName() {
+        return bindingName;
+    }
+
+    public Object getBoundObject() {
+        return boundObject;
+    }
+}

dynjs/src/test/java/org/dynjs/runtime/DynJSTest.java

@@ -17,6 +17,7 @@
 package org.dynjs.runtime;
 
 import org.dynjs.api.Function;
+import org.dynjs.api.Scope;
 import org.dynjs.exception.ReferenceError;
 import org.junit.Before;
 import org.junit.Test;
@@ -27,10 +28,11 @@ public class DynJSTest {
 
     private DynJS dynJS;
     private DynThreadContext context;
+    private DynJSConfig config;
 
     @Before
     public void setUp() {
-        DynJSConfig config = new DynJSConfig();
+        config = new DynJSConfig();
 //        config.enableDebug();
         dynJS = new DynJS(config);
         context = new DynThreadContext();
@@ -240,6 +242,12 @@ public void testLiteralArray() {
         check("var x = []; x[33] = 'lol'; var result = x[33] == 'lol';");
     }
 
+    @Test
+    public void testBuiltinLoading() {
+        config.addBuiltin("sample", new BypassFunction());
+        check("var result = sample(true);");
+    }
+
     private void check(String scriptlet) {
         check(scriptlet, true);
     }
@@ -250,4 +258,30 @@ private void check(String scriptlet, Boolean expected) {
         assertThat(result).isEqualTo(expected);
     }
 
+    private class BypassFunction implements Function{
+        @Override
+        public Object call(DynThreadContext context, Object[] arguments) {
+            return arguments[0];
+        }
+
+        @Override
+        public void setContext(DynThreadContext context) {
+            //To change body of implemented methods use File | Settings | File Templates.
+        }
+
+        @Override
+        public Scope getEnclosingScope() {
+            return null;  //To change body of implemented methods use File | Settings | File Templates.
+        }
+
+        @Override
+        public Object resolve(String name) {
+            return null;  //To change body of implemented methods use File | Settings | File Templates.
+        }
+
+        @Override
+        public void define(String property, Object value) {
+            //To change body of implemented methods use File | Settings | File Templates.
+        }
+    }
 }