Extract forEach over two iterabes

4 files changed, 34 insertions, 7 deletions

diff --git a/src/main/java/org/zwobble/couscous/interpreter/Executor.java b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
index fcdca98..d85013e 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Executor.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
@@ -13,6 +13,7 @@ import java.util.stream.Stream;
 import static org.zwobble.couscous.ast.structure.NodeStructure.descendantNodesAndSelf;
 import static org.zwobble.couscous.interpreter.Evaluator.eval;
 import static org.zwobble.couscous.interpreter.Evaluator.evalCondition;
+import static org.zwobble.couscous.util.ExtraIterables.forEach;
 
 public class Executor implements StatementNodeMapper<Optional<InterpreterValue>> {
     public static InterpreterValue callMethod(
@@ -53,11 +54,8 @@ public class Executor implements StatementNodeMapper<Optional<InterpreterValue>>
         Optional<InterpreterValue> thisValue,
         PositionalArguments arguments)
     {
-        // TODO use map with multiple iterables
         StackFrameBuilder stackFrame = new StackFrameBuilder();
-        for (int index = 0; index < formalArguments.size(); index++) {
-            stackFrame.declare(formalArguments.get(index), arguments.get(index));
-        }
+        forEach(formalArguments, arguments, stackFrame::declare);
         findDeclarations(statements).forEach(declaration -> stackFrame.declare(declaration));
         return environment.withStackFrame(thisValue, stackFrame.build());
     }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/PositionalArguments.java b/src/main/java/org/zwobble/couscous/interpreter/PositionalArguments.java
index 429b529..2ceb986 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/PositionalArguments.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/PositionalArguments.java
@@ -1,10 +1,11 @@
 package org.zwobble.couscous.interpreter;
 
-import java.util.List;
-
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
 
-public class PositionalArguments {
+import java.util.Iterator;
+import java.util.List;
+
+public class PositionalArguments implements Iterable<InterpreterValue> {
     private List<InterpreterValue> values;
     
     public PositionalArguments(List<InterpreterValue> values) {
@@ -14,4 +15,9 @@ public class PositionalArguments {
     public InterpreterValue get(int index) {
         return values.get(index);
     }
+
+    @Override
+    public Iterator<InterpreterValue> iterator() {
+        return values.iterator();
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/util/Action2.java b/src/main/java/org/zwobble/couscous/util/Action2.java
new file mode 100644
index 0000000..4086f1d
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/util/Action2.java
@@ -0,0 +1,5 @@
+package org.zwobble.couscous.util;
+
+public interface Action2<T, U> {
+    void run(T first, U second);
+}
diff --git a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
new file mode 100644
index 0000000..9cdb0f0
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
@@ -0,0 +1,18 @@
+package org.zwobble.couscous.util;
+
+import java.util.Iterator;
+
+public class ExtraIterables {
+    private ExtraIterables() {}
+
+    public static <T, U> void forEach(Iterable<? extends T> first, Iterable<? extends U> second, Action2<T, U> action) {
+        Iterator<? extends T> firstIterator = first.iterator();
+        Iterator<? extends U> secondIterator = second.iterator();
+        while (firstIterator.hasNext()) {
+            action.run(firstIterator.next(), secondIterator.next());
+        }
+        if (secondIterator.hasNext()) {
+            throw new RuntimeException("Iterables not of same length");
+        }
+    }
+}