GH-392 Make sure that method returns value

examples/tests/current_test.panda

@@ -237,7 +237,12 @@ internal class Test {
 
     // get test instance
     shared Test getTestField() {
-        return this.testField
+        if true {
+            return this.testField
+        }
+        else {
+            return null
+        }
     }
 
 }

panda/src/main/java/org/panda_lang/panda/language/interpreter/parser/block/BlockParser.java

@@ -17,8 +17,8 @@
 package org.panda_lang.panda.language.interpreter.parser.block;
 
 import org.jetbrains.annotations.Nullable;
-import org.panda_lang.framework.design.architecture.statement.Cell;
 import org.panda_lang.framework.design.architecture.statement.Scope;
+import org.panda_lang.framework.design.architecture.statement.Statement;
 import org.panda_lang.framework.design.interpreter.parser.Components;
 import org.panda_lang.framework.design.interpreter.parser.Context;
 import org.panda_lang.framework.design.interpreter.parser.pipeline.Channel;
@@ -74,11 +74,11 @@ void parse(Context context, LocalData local, @Component Channel channel, @Compon
         BlockSubparser blockParser = channel.get("result", BlockSubparser.class);
         Context delegatedContext = local.allocated(context.fork()).withComponent(Components.CHANNEL, channel);
 
-        if (!parent.getCells().isEmpty()) {
-            Cell cell = parent.getCells().get(parent.getCells().size() - 1);
+        if (!parent.getStatements().isEmpty()) {
+            Statement statement = parent.getStatements().get(parent.getStatements().size() - 1);
 
-            if (cell.getStatement() instanceof BlockStatement) {
-                delegatedContext.withComponent(BlockComponents.PREVIOUS_BLOCK, ((BlockStatement) cell.getStatement()).getBlock());
+            if (statement instanceof BlockStatement) {
+                delegatedContext.withComponent(BlockComponents.PREVIOUS_BLOCK, ((BlockStatement) statement).getBlock());
             }
         }
 

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/prototype/MethodParser.java

@@ -27,6 +27,7 @@
 import org.panda_lang.framework.design.interpreter.parser.pipeline.Pipelines;
 import org.panda_lang.framework.design.interpreter.source.SourceLocation;
 import org.panda_lang.framework.design.interpreter.token.Snippet;
+import org.panda_lang.framework.design.interpreter.token.SnippetUtils;
 import org.panda_lang.framework.design.interpreter.token.TokenRepresentation;
 import org.panda_lang.framework.language.architecture.prototype.MethodScope;
 import org.panda_lang.framework.language.architecture.prototype.PandaMethod;
@@ -59,6 +60,7 @@
 import org.panda_lang.panda.language.interpreter.parser.context.handlers.CustomPatternHandler;
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.CustomPatternInterceptor;
 import org.panda_lang.panda.language.resource.syntax.PandaPriorities;
+import org.panda_lang.panda.language.resource.syntax.scope.branching.Returnable;
 
 import java.util.List;
 import java.util.Optional;
@@ -113,7 +115,7 @@ void parse(Context context, LocalData local, @Component Prototype prototype, @In
             );
         }
 
-        PandaMethod method = PandaMethod.builder()
+        PandaMethod method = local.allocated(PandaMethod.builder()
                 .prototype(prototype)
                 .parameters(parameters)
                 .name(name.getValue())
@@ -124,15 +126,19 @@ void parse(Context context, LocalData local, @Component Prototype prototype, @In
                 .isStatic(result.has("static"))
                 .isNative(existingMethod.isPresent() && existingMethod.get().isNative())
                 .methodBody(methodScope)
-                .build();
+                .build());
 
         prototype.getMethods().declare(method);
     }
 
     @Autowired(order = 2, delegation = Delegation.NEXT_DEFAULT)
-    void parse(Context delegatedContext, @Local MethodScope methodScope, @Nullable @Src("body") Snippet body) throws Exception {
-        if (body != null) {
-            SCOPE_PARSER.parse(delegatedContext, methodScope, body);
+    void parse(Context context, @Local MethodScope methodScope, @Local PrototypeMethod method, @Nullable @Src("body") Snippet body) throws Exception {
+        if (!SnippetUtils.isEmpty(body)) {
+            SCOPE_PARSER.parse(context, methodScope, body);
+        }
+
+        if (!void.class.isAssignableFrom(method.getType().getAssociatedClass().getImplementation()) && !methodScope.hasEffective(Returnable.class)) {
+            throw new PandaParserFailure(context, "Missing return statement in method " + method.getPropertyName());
         }
     }
 

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/LogParser.java

@@ -39,6 +39,8 @@
 import org.panda_lang.panda.language.interpreter.parser.context.handlers.TokenHandler;
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.CustomPatternInterceptor;
 
+import java.util.Arrays;
+
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL)
 public final class LogParser extends ParserBootstrap<Object> {
 
@@ -55,11 +57,9 @@ protected BootstrapInitializer<Object> initialize(Context context, BootstrapInit
 
     @Autowired
     void parse(Context context, @Component ExpressionParser parser, @Component Scope scope, @Inter SourceLocation location, @Src("arguments") ExpressionTransaction[] transactions) {
-        Expression[] expressions = new Expression[transactions.length];
-
-        for (int index = 0; index < transactions.length; index++) {
-            expressions[index] = transactions[index].getExpression();
-        }
+        Expression[] expressions = Arrays.stream(transactions)
+                .map(ExpressionTransaction::getExpression)
+                .toArray(Expression[]::new);
 
         Messenger messenger = context.getComponent(Components.ENVIRONMENT).getMessenger();
         scope.addStatement(new LogStatement(location, messenger, expressions));

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/StandaloneExpressionParser.java

@@ -39,7 +39,7 @@
 import org.panda_lang.panda.language.resource.syntax.PandaPriorities;
 
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL, priority = PandaPriorities.SCOPE_EXPRESSION)
-public final class StandaloneExpressionParser extends ParserBootstrap {
+public final class StandaloneExpressionParser extends ParserBootstrap<Object> {
 
     private static final ExpressionParserSettings SETTINGS = ExpressionParserSettings.create()
             .onlyStandalone()
@@ -48,7 +48,7 @@ public final class StandaloneExpressionParser extends ParserBootstrap {
     private ExpressionParser expressionParser;
 
     @Override
-    protected BootstrapInitializer initialize(Context context, BootstrapInitializer initializer) {
+    protected BootstrapInitializer<Object> initialize(Context context, BootstrapInitializer<Object> initializer) {
         this.expressionParser = context.getComponent(Components.EXPRESSION);
         return initializer;
     }

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/TryCatchParser.java

@@ -40,12 +40,12 @@
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.LinearPatternInterceptor;
 
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL)
-public final class TryCatchParser extends ParserBootstrap {
+public final class TryCatchParser extends ParserBootstrap<Object> {
 
     private static final ScopeParser SCOPE_PARSER = new ScopeParser();
 
     @Override
-    protected BootstrapInitializer initialize(Context context, BootstrapInitializer initializer) {
+    protected BootstrapInitializer<Object> initialize(Context context, BootstrapInitializer<Object> initializer) {
         return initializer
                 .handler(new TokenHandler(Keywords.TRY))
                 .interceptor(new LinearPatternInterceptor())

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/BreakParser.java

@@ -35,10 +35,10 @@
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.LinearPatternInterceptor;
 
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL)
-public final class BreakParser extends ParserBootstrap {
+public final class BreakParser extends ParserBootstrap<Object> {
 
     @Override
-    protected BootstrapInitializer initialize(Context context, BootstrapInitializer initializer) {
+    protected BootstrapInitializer<Object> initialize(Context context, BootstrapInitializer<Object> initializer) {
         return initializer
                 .handler(new TokenHandler(Keywords.BREAK))
                 .interceptor(new LinearPatternInterceptor())

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/ContinueParser.java

@@ -35,10 +35,10 @@
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.LinearPatternInterceptor;
 
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL)
-public final class ContinueParser extends ParserBootstrap {
+public final class ContinueParser extends ParserBootstrap<Object> {
 
     @Override
-    protected BootstrapInitializer initialize(Context context, BootstrapInitializer initializer) {
+    protected BootstrapInitializer<Object> initialize(Context context, BootstrapInitializer<Object> initializer) {
         return initializer
                 .handler(new TokenHandler(Keywords.CONTINUE))
                 .interceptor(new LinearPatternInterceptor())

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/Return.java

@@ -24,7 +24,7 @@
 import org.panda_lang.framework.design.runtime.Status;
 import org.panda_lang.framework.language.architecture.dynamic.AbstractExecutableStatement;
 
-final class Return extends AbstractExecutableStatement implements Controller {
+final class Return extends AbstractExecutableStatement implements Returnable, Controller {
 
     private final Expression value;
 

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/ReturnParser.java

@@ -34,19 +34,19 @@
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.LinearPatternInterceptor;
 
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL)
-public final class ReturnParser extends ParserBootstrap {
+public final class ReturnParser extends ParserBootstrap<Object> {
 
     @Override
-    protected BootstrapInitializer initialize(Context context, BootstrapInitializer initializer) {
+    protected BootstrapInitializer<Object> initialize(Context context, BootstrapInitializer<Object> initializer) {
         return initializer
                 .handler(new TokenHandler(Keywords.RETURN))
                 .interceptor(new LinearPatternInterceptor())
                 .pattern("return &value:*=expression");
     }
 
     @Autowired
-    void parse(@Component Scope block, @Inter SourceLocation location, @Src("value") @Nullable Expression value) {
-        block.addStatement(new Return(location, value));
+    void parse(@Component Scope scope, @Inter SourceLocation location, @Src("value") @Nullable Expression value) {
+        scope.addStatement(new Return(location, value));
     }
 
 }

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/Returnable.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2015-2019 Dzikoysk
+ *
+ * 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.panda_lang.panda.language.resource.syntax.scope.branching;
+
+import org.panda_lang.framework.design.architecture.statement.Statement;
+
+public interface Returnable extends Statement {
+
+}

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/Throw.java

@@ -24,7 +24,7 @@
 import org.panda_lang.framework.language.architecture.dynamic.AbstractExecutableStatement;
 import org.panda_lang.utilities.commons.UnsafeUtils;
 
-final class Throw extends AbstractExecutableStatement implements Controller {
+final class Throw extends AbstractExecutableStatement implements Returnable, Controller {
 
     private final Expression value;
 

panda/src/main/java/org/panda_lang/panda/language/resource/syntax/scope/branching/ThrowParser.java

@@ -33,10 +33,10 @@
 import org.panda_lang.panda.language.interpreter.parser.context.interceptors.LinearPatternInterceptor;
 
 @RegistrableParser(pipeline = Pipelines.SCOPE_LABEL)
-public final class ThrowParser extends ParserBootstrap {
+public final class ThrowParser extends ParserBootstrap<Object> {
 
     @Override
-    protected BootstrapInitializer initialize(Context context, BootstrapInitializer initializer) {
+    protected BootstrapInitializer<Object> initialize(Context context, BootstrapInitializer<Object> initializer) {
         return initializer
                 .handler(new TokenHandler(Keywords.THROW))
                 .interceptor(new LinearPatternInterceptor())