Combine code for reading conditions in interpreter

2 files changed, 18 insertions, 15 deletions

diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index 3bcf3ac..e715caa 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -18,6 +18,10 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
     public static InterpreterValue eval(Environment environment, ExpressionNode expression) {
         return new Evaluator(environment).eval(expression);
     }
+
+    public static boolean evalCondition(Environment environment, ExpressionNode expression) {
+        return new Evaluator(environment).evalCondition(expression);
+    }
     
     private final Environment environment;
     
@@ -67,14 +71,19 @@ public class Evaluator implements ExpressionNodeMapper<InterpreterValue> {
     
     @Override
     public InterpreterValue visit(TernaryConditionalNode ternaryConditional) {
-        InterpreterValue condition = eval(ternaryConditional.getCondition());
-        if (!(condition instanceof BooleanInterpreterValue)) {
-            throw new ConditionMustBeBoolean(condition);
-        }
-        final org.zwobble.couscous.ast.ExpressionNode branch = ((BooleanInterpreterValue)condition).getValue() ? ternaryConditional.getIfTrue() : ternaryConditional.getIfFalse();
+        boolean condition = evalCondition(ternaryConditional.getCondition());
+        ExpressionNode branch = condition ? ternaryConditional.getIfTrue() : ternaryConditional.getIfFalse();
         return eval(branch);
     }
-    
+
+    private boolean evalCondition(ExpressionNode condition) {
+        InterpreterValue value = eval(condition);
+        if (!(value instanceof BooleanInterpreterValue)) {
+            throw new ConditionMustBeBoolean(value);
+        }
+        return ((BooleanInterpreterValue)value).getValue();
+    }
+
     @Override
     public InterpreterValue visit(MethodCallNode methodCall) {
         List<InterpreterValue> arguments = evalArguments(methodCall.getArguments());
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Executor.java b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
index 556e7d1..6de4828 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Executor.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Executor.java
@@ -1,10 +1,8 @@
 package org.zwobble.couscous.interpreter;
 
 import org.zwobble.couscous.ast.*;
-import org.zwobble.couscous.ast.structure.NodeStructure;
 import org.zwobble.couscous.ast.visitors.NodeMapperWithDefault;
 import org.zwobble.couscous.ast.visitors.StatementNodeMapper;
-import org.zwobble.couscous.interpreter.values.BooleanInterpreterValue;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
 import org.zwobble.couscous.interpreter.values.UnitInterpreterValue;
 
@@ -14,6 +12,7 @@ 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;
 
 public class Executor implements StatementNodeMapper<Optional<InterpreterValue>> {
     public static InterpreterValue callMethod(Environment environment, CallableNode method, Optional<InterpreterValue> thisValue, PositionalArguments arguments) {
@@ -76,7 +75,7 @@ public class Executor implements StatementNodeMapper<Optional<InterpreterValue>>
 
     @Override
     public Optional<InterpreterValue> visit(IfStatementNode ifStatement) {
-        List<StatementNode> body = evalCondition(ifStatement.getCondition())
+        List<StatementNode> body = evalCondition(environment, ifStatement.getCondition())
             ? ifStatement.getTrueBranch()
             : ifStatement.getFalseBranch();
         return exec(body);
@@ -84,7 +83,7 @@ public class Executor implements StatementNodeMapper<Optional<InterpreterValue>>
 
     @Override
     public Optional<InterpreterValue> visit(WhileNode whileLoop) {
-        while (evalCondition(whileLoop.getCondition())) {
+        while (evalCondition(environment, whileLoop.getCondition())) {
             Optional<InterpreterValue> result = exec(whileLoop.getBody());
             if (result.isPresent()) {
                 return result;
@@ -93,11 +92,6 @@ public class Executor implements StatementNodeMapper<Optional<InterpreterValue>>
         return Optional.empty();
     }
 
-    private boolean evalCondition(ExpressionNode conditionExpression) {
-        BooleanInterpreterValue condition = (BooleanInterpreterValue) eval(environment, conditionExpression);
-        return condition.getValue();
-    }
-
     private Optional<InterpreterValue> exec(List<StatementNode> statements) {
         for (StatementNode statement : statements) {
             Optional<InterpreterValue> result = exec(environment, statement);