Строгое преобразование строк в числа

src/main/java/com/annimon/ownlang/lib/StringValue.java

@@ -87,20 +87,12 @@ public final class StringValue implements Value {
     
     @Override
     public int asInt() {
-        try {
         return Integer.parseInt(value);
-        } catch (NumberFormatException e) {
-            return 0;
-        }
     }
     
     @Override
     public double asNumber() {
-        try {
         return Double.parseDouble(value);
-        } catch (NumberFormatException e) {
-            return 0;
-        }
     }
 
     @Override

src/test/java/com/annimon/ownlang/parser/ParserTest.java

@@ -35,9 +35,12 @@ public class ParserTest {
         BlockStatement program = assertExpression(input, expected);
         program.execute();
         final Value actual = Variables.get("a");
+        try {
             assertEquals(expectedValue.asNumber(), actual.asNumber(), 0.001);
+        } catch (NumberFormatException nfe) {
             assertEquals(expectedValue.asString(), actual.asString());
         }
+    }
     
     private static BlockStatement assertExpression(String input, Expression expected) {
         return assertProgram("a = " + input, block(assign("a", expected)));

src/test/java/com/annimon/ownlang/parser/ast/VariableExpressionTest.java

@@ -1,6 +1,7 @@
 package com.annimon.ownlang.parser.ast;
 
 import static com.annimon.ownlang.parser.ast.ASTHelper.*;
+import com.annimon.ownlang.exceptions.VariableDoesNotExistsException;
 import org.junit.Test;
 
 /**
@@ -26,7 +27,7 @@ public class VariableExpressionTest {
         assertValue(number(8), var("a").eval());
     }
     
-    @Test(expected = RuntimeException.class)
+    @Test(expected = VariableDoesNotExistsException.class)
     public void testUnknownVariable() {
         var("a").eval();
     }