Move standard type definitions into a Types class

10 files changed, 136 insertions, 152 deletions

diff --git a/src/test/java/org/zwobble/couscous/tests/BackendEvalTests.java b/src/test/java/org/zwobble/couscous/tests/BackendEvalTests.java
index cccd305..c9c7414 100644
--- a/src/test/java/org/zwobble/couscous/tests/BackendEvalTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/BackendEvalTests.java
@@ -3,9 +3,8 @@ package org.zwobble.couscous.tests;
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.types.ScalarType;
-import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.values.PrimitiveValue;
-import org.zwobble.couscous.values.StringValue;
 
 import java.util.Collections;
 import java.util.List;
@@ -35,7 +34,7 @@ public abstract class BackendEvalTests {
         assertEquals(value(true), evalExpression(literal(true)));
         assertEquals(value(false), evalExpression(literal(false)));
         assertEquals(value(42), evalExpression(literal(42)));
-        assertEquals(value(StringValue.REF), evalExpression(literal(StringValue.REF)));
+        assertEquals(value(Types.STRING), evalExpression(literal(Types.STRING)));
     }
     
     @Test
@@ -127,7 +126,7 @@ public abstract class BackendEvalTests {
             literal("hello"),
             "length",
             list(),
-            IntegerValue.REF));
+            Types.INT));
         assertEquals(value(5), result);
     }
     
@@ -137,7 +136,7 @@ public abstract class BackendEvalTests {
             literal("hello"),
             "substring",
             list(literal(1), literal(4)),
-            StringValue.REF));
+            Types.STRING));
         assertEquals(value("ell"), result);
     }
     
@@ -147,7 +146,7 @@ public abstract class BackendEvalTests {
             "java.lang.Integer",
             "parseInt",
             list(literal("42")),
-            IntegerValue.REF));
+            Types.INT));
         assertEquals(value(42), result);
     }
     
@@ -155,15 +154,15 @@ public abstract class BackendEvalTests {
     public void canCallStaticMethodFromUserDefinedStaticMethod() {
         ClassNode classNode = ClassNode.builder("com.example.Example")
             .staticMethod("main", method -> method
-                .returns(IntegerValue.REF)
+                .returns(Types.INT)
                 .statement(returns(staticMethodCall(
                     "java.lang.Integer",
                     "parseInt",
                     list(literal("42")),
-                    IntegerValue.REF))))
+                    Types.INT))))
             .build();
         PrimitiveValue result = evalExpression(list(classNode),
-            staticMethodCall("com.example.Example", "main", list(), IntegerValue.REF));
+            staticMethodCall("com.example.Example", "main", list(), Types.INT));
         assertEquals(value(42), result);
     }
     
@@ -171,21 +170,21 @@ public abstract class BackendEvalTests {
     public void canCallInstanceMethodWithNoArgumentsOnUserDefinedClass() {
         ClassNode classNode = ClassNode.builder("com.example.Example")
             .method("main", method -> method
-                .returns(IntegerValue.REF)
+                .returns(Types.INT)
                 .statement(returns(literal(42))))
             .build();
         PrimitiveValue result = evalExpression(list(classNode),
-            methodCall(constructorCall(classNode.getName(), list()), "main", list(), IntegerValue.REF));
+            methodCall(constructorCall(classNode.getName(), list()), "main", list(), Types.INT));
         assertEquals(value(42), result);
     }
     
     @Test
     public void canCallInstanceMethodWithArgumentsOnUserDefinedClass() {
-        FormalArgumentNode argument = formalArg(var(ANY_ID, "x", IntegerValue.REF));
+        FormalArgumentNode argument = formalArg(var(ANY_ID, "x", Types.INT));
         ClassNode classNode = ClassNode.builder("com.example.Example")
             .method("main", method -> method
                 .argument(argument)
-                .returns(IntegerValue.REF)
+                .returns(Types.INT)
                 .statement(returns(reference(argument))))
             .build();
         
@@ -195,25 +194,25 @@ public abstract class BackendEvalTests {
                 constructorCall(classNode.getName(), list()),
                 "main",
                 list(literal(42)),
-                IntegerValue.REF));
+                Types.INT));
         
         assertEquals(value(42), result);
     }
     
     @Test
     public void constructorIsExecutedOnConstruction() {
-        FormalArgumentNode argument = formalArg(var(ANY_ID, "x", IntegerValue.REF));
+        FormalArgumentNode argument = formalArg(var(ANY_ID, "x", Types.INT));
         ClassNode classNode = ClassNode.builder("com.example.Example")
-            .field("value", IntegerValue.REF)
+            .field("value", Types.INT)
             .constructor(constructor -> constructor
                 .argument(argument)
                 .statement(assignStatement(
-                    fieldAccess(constructor.thisReference(), "value", IntegerValue.REF),
+                    fieldAccess(constructor.thisReference(), "value", Types.INT),
                     reference(argument))))
             .method("main", method -> method
-                .returns(IntegerValue.REF)
+                .returns(Types.INT)
                 .statement(returns(
-                    fieldAccess(method.thisReference(), "value", IntegerValue.REF))))
+                    fieldAccess(method.thisReference(), "value", Types.INT))))
             .build();
         
         PrimitiveValue result = evalExpression(
@@ -222,7 +221,7 @@ public abstract class BackendEvalTests {
                 constructorCall(classNode.getName(), list(literal(42))),
                 "main",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
         
         assertEquals(value(42), result);
     }
@@ -231,16 +230,16 @@ public abstract class BackendEvalTests {
     public void staticConstructorIsExecutedOnReference() {
         ScalarType type = ScalarType.of("com.example.Example");
         ClassNode classNode = ClassNode.builder(type)
-            .staticField("value", IntegerValue.REF)
+            .staticField("value", Types.INT)
             .staticConstructor(list(
                 assignStatement(
-                    fieldAccess(type, "value", IntegerValue.REF),
+                    fieldAccess(type, "value", Types.INT),
                     literal(42))))
             .build();
 
         PrimitiveValue result = evalExpression(
             list(classNode),
-            fieldAccess(type, "value", IntegerValue.REF));
+            fieldAccess(type, "value", Types.INT));
 
         assertEquals(value(42), result);
     }
diff --git a/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java b/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java
index c8b2b70..635dae8 100644
--- a/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/BackendMethodTests.java
@@ -2,10 +2,9 @@ package org.zwobble.couscous.tests;
 
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
-import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.values.PrimitiveValue;
 import org.zwobble.couscous.values.PrimitiveValues;
-import org.zwobble.couscous.values.StringValue;
 
 import static java.util.Arrays.asList;
 import static org.junit.Assert.assertEquals;
@@ -38,7 +37,7 @@ public abstract class BackendMethodTests {
     @Test
     public void canReturnLiteralValue() {
         MethodNode.Builder method = staticMethod("hello")
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(returns(literal("hello, world!")));
         final java.lang.Object result = runMethod(method);
         assertEquals(value("hello, world!"), result);
@@ -46,10 +45,10 @@ public abstract class BackendMethodTests {
     
     @Test
     public void canPassValueToMethod() {
-        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", StringValue.REF));
+        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", Types.STRING));
         MethodNode.Builder method = staticMethod("hello")
             .argument(arg)
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(returns(reference(arg)));
         final java.lang.Object result = runMethod(method, value("hello, world!"));
         assertEquals(value("hello, world!"), result);
@@ -57,10 +56,10 @@ public abstract class BackendMethodTests {
     
     @Test
     public void canReassignValueToArgument() {
-        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", StringValue.REF));
+        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", Types.STRING));
         MethodNode.Builder method = staticMethod("hello")
             .argument(arg)
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(expressionStatement(assign(
                 reference(arg),
                 literal("[updated value]"))))
@@ -71,9 +70,9 @@ public abstract class BackendMethodTests {
     
     @Test
     public void canDeclareVariable() {
-        LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(ANY_ID, "x", StringValue.REF, LiteralNode.literal("[initial value]"));
+        LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(ANY_ID, "x", Types.STRING, LiteralNode.literal("[initial value]"));
         MethodNode.Builder method = staticMethod("hello")
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(localVariableDeclaration)
             .statement(returns(reference(localVariableDeclaration)));
         final java.lang.Object result = runMethod(method);
@@ -82,9 +81,9 @@ public abstract class BackendMethodTests {
     
     @Test
     public void canDeclareVariableAndThenAssignValues() {
-        LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(ANY_ID, "x", StringValue.REF, LiteralNode.literal("[initial value]"));
+        LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(ANY_ID, "x", Types.STRING, LiteralNode.literal("[initial value]"));
         MethodNode.Builder method = staticMethod("hello")
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(localVariableDeclaration)
             .statement(expressionStatement(assign(
                 reference(localVariableDeclaration),
@@ -97,7 +96,7 @@ public abstract class BackendMethodTests {
     @Test
     public void whenConditionIsTrueIfStatementExecutesTrueBranch() {
         MethodNode.Builder method = staticMethod("hello")
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(ifStatement(
                 literal(true),
                 list(returns(literal("[true]"))),
@@ -108,7 +107,7 @@ public abstract class BackendMethodTests {
     @Test
     public void whenConditionIsFalseIfStatementExecutesTrueBranch() {
         MethodNode.Builder method = staticMethod("hello")
-            .returns(StringValue.REF)
+            .returns(Types.STRING)
             .statement(ifStatement(
                 literal(false),
                 list(returns(literal("[true]"))),
@@ -118,10 +117,10 @@ public abstract class BackendMethodTests {
 
     @Test
     public void whileLoopIsExecutedWhileConditionIsTrue() {
-        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.id("x"), "x", IntegerValue.REF, literal(0));
-        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.id("y"), "y", IntegerValue.REF, literal(2));
+        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.id("x"), "x", Types.INT, literal(0));
+        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.id("y"), "y", Types.INT, literal(2));
         MethodNode.Builder method = staticMethod("hello")
-            .returns(IntegerValue.REF)
+            .returns(Types.INT)
             .statement(x)
             .statement(y)
             .statement(whileLoop(
@@ -133,10 +132,10 @@ public abstract class BackendMethodTests {
 
     @Test
     public void returnWillExitWhileLoopEarly() {
-        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.id("x"), "x", IntegerValue.REF, literal(0));
-        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.id("y"), "y", IntegerValue.REF, literal(2));
+        LocalVariableDeclarationNode x = localVariableDeclaration(TestIds.id("x"), "x", Types.INT, literal(0));
+        LocalVariableDeclarationNode y = localVariableDeclaration(TestIds.id("y"), "y", Types.INT, literal(2));
         MethodNode.Builder method = staticMethod("hello")
-            .returns(IntegerValue.REF)
+            .returns(Types.INT)
             .statement(x)
             .statement(y)
             .statement(whileLoop(
diff --git a/src/test/java/org/zwobble/couscous/tests/CompilerTests.java b/src/test/java/org/zwobble/couscous/tests/CompilerTests.java
index ae8376b..7df7582 100644
--- a/src/test/java/org/zwobble/couscous/tests/CompilerTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/CompilerTests.java
@@ -2,10 +2,8 @@ package org.zwobble.couscous.tests;
 
 import org.junit.Test;
 import org.zwobble.couscous.types.ScalarType;
-import org.zwobble.couscous.values.BooleanValue;
-import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.values.PrimitiveValue;
-import org.zwobble.couscous.values.StringValue;
 
 import java.io.File;
 import java.io.IOException;
@@ -23,7 +21,7 @@ import static org.zwobble.couscous.values.PrimitiveValues.value;
 public abstract class CompilerTests {
     @Test
     public void canEvaluateLiterals() {
-        assertEquals(value("hello"), evalExpression(StringValue.REF, "\"hello\""));
+        assertEquals(value("hello"), evalExpression(Types.STRING, "\"hello\""));
         assertEquals(value(42), evalIntExpression("42"));
     }
 
@@ -41,13 +39,13 @@ public abstract class CompilerTests {
     @Test
     public void equalityOnReferenceTypesChecksForIdentity() {
         assertEquals(value(false), evalBooleanExpression("new Object() == new Object()"));
-        assertEquals(value(true), exec(BooleanValue.REF, "Object x = new Object(); return x == x;"));
+        assertEquals(value(true), exec(Types.BOOLEAN, "Object x = new Object(); return x == x;"));
     }
 
     @Test
     public void integersCanBeAssignedToObjectVariable() {
-        assertEquals(value(false), exec(BooleanValue.REF, "Object x = 1; return x.equals(new Object());"));
-        assertEquals(value(true), exec(BooleanValue.REF, "Object x = 1; return x.equals(1);"));
+        assertEquals(value(false), exec(Types.BOOLEAN, "Object x = 1; return x.equals(new Object());"));
+        assertEquals(value(true), exec(Types.BOOLEAN, "Object x = 1; return x.equals(1);"));
     }
 
     @Test
@@ -59,7 +57,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.RecursiveFactorial"),
                 "factorial",
                 list(value(6)),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -71,7 +69,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.WhileFactorial"),
                 "factorial",
                 list(value(6)),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -83,7 +81,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.ForFactorial"),
                 "factorial",
                 list(value(6)),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -95,7 +93,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.StaticNestedClass"),
                 "value",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -107,7 +105,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.InnerClass"),
                 "run",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -119,7 +117,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.InnerClass"),
                 "run",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -131,7 +129,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.ConstantIntSupplier"),
                 "value",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -143,7 +141,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.AnonymousClass"),
                 "value",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -155,7 +153,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.AnonymousClass"),
                 "value",
                 list(value(42)),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -167,7 +165,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.Lambda"),
                 "value",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -179,7 +177,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.Lambda"),
                 "value",
                 list(value(2)),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -191,7 +189,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.Lambda"),
                 "value",
                 list(value(2)),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
@@ -203,7 +201,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.GenericInterface"),
                 "value",
                 list(),
-                StringValue.REF));
+                Types.STRING));
     }
 
     @Test
@@ -215,7 +213,7 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.GenericInterface"),
                 "value",
                 list(),
-                StringValue.REF));
+                Types.STRING));
     }
 
     @Test
@@ -227,17 +225,17 @@ public abstract class CompilerTests {
                 ScalarType.of("com.example.StaticMethodOverloads"),
                 "value",
                 list(),
-                IntegerValue.REF));
+                Types.INT));
     }
 
     @Test
     public void stringAdd() throws Exception {
-        assertEquals(value("42"), evalExpression(StringValue.REF, "\"4\" + \"2\""));
+        assertEquals(value("42"), evalExpression(Types.STRING, "\"4\" + \"2\""));
     }
 
     @Test
     public void stringToLowerCase() throws Exception {
-        assertEquals(value("patrick wolf"), evalExpression(StringValue.REF, "\"Patrick Wolf\".toLowerCase()"));
+        assertEquals(value("patrick wolf"), evalExpression(Types.STRING, "\"Patrick Wolf\".toLowerCase()"));
     }
 
     @Test
@@ -305,11 +303,11 @@ public abstract class CompilerTests {
     }
 
     private PrimitiveValue evalBooleanExpression(String expressionSource) {
-        return evalExpression(BooleanValue.REF, expressionSource);
+        return evalExpression(Types.BOOLEAN, expressionSource);
     }
 
     private PrimitiveValue evalIntExpression(String expressionSource) {
-        return evalExpression(IntegerValue.REF, expressionSource);
+        return evalExpression(Types.INT, expressionSource);
     }
 
     private PrimitiveValue evalExpression(ScalarType type, String expressionSource) {
diff --git a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpMethodRunner.java b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpMethodRunner.java
index 2ca3b2d..fbc3c54 100644
--- a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpMethodRunner.java
+++ b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpMethodRunner.java
@@ -14,11 +14,10 @@ import org.zwobble.couscous.backends.csharp.CsharpBackend;
 import org.zwobble.couscous.backends.csharp.CsharpSerializer;
 import org.zwobble.couscous.tests.MethodRunner;
 import org.zwobble.couscous.tests.backends.Processes;
+import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.util.ExtraLists;
 import org.zwobble.couscous.values.PrimitiveValue;
 import org.zwobble.couscous.values.PrimitiveValues;
-import org.zwobble.couscous.values.StringValue;
-import org.zwobble.couscous.values.UnitValue;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -72,7 +71,7 @@ public class CsharpMethodRunner implements MethodRunner {
                 eagerMap(arguments, LiteralNode::literal),
                 returnType));
 
-        boolean isVoid = returnType.equals(UnitValue.REF);
+        boolean isVoid = returnType.equals(Types.VOID);
         String body = isVoid
             ? value + ";"
             : "var value = " + value + ";" +
@@ -123,7 +122,7 @@ public class CsharpMethodRunner implements MethodRunner {
                 return value(value.equals("True"));
             case "System.MonoType":
                 if (value.equals("System.String")) {
-                    return value(StringValue.REF);
+                    return value(Types.STRING);
                 } else {
                     assertThat(value, Matchers.startsWith(NAMESPACE_PREFIX));
                     return value(ScalarType.of(value.substring(NAMESPACE_PREFIX.length())));
diff --git a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
index 3eebf1a..5c1044d 100644
--- a/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/backends/csharp/CsharpSerializerTests.java
@@ -5,8 +5,7 @@ import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.backends.csharp.CsharpSerializer;
 import org.zwobble.couscous.tests.TestIds;
-import org.zwobble.couscous.values.BooleanValue;
-import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.types.Types;
 
 import static org.junit.Assert.assertEquals;
 import static org.zwobble.couscous.ast.AssignmentNode.assign;
@@ -71,7 +70,7 @@ public class CsharpSerializerTests {
     @Test
     public void assignmentSeparatesTargetAndValueWithEqualsSign() {
         String output = serialize(assign(
-            reference(var(TestIds.ANY_ID, "x", BooleanValue.REF)),
+            reference(var(TestIds.ANY_ID, "x", Types.BOOLEAN)),
             literal(true)));
         assertEquals("x = true", output);
     }
@@ -131,7 +130,7 @@ public class CsharpSerializerTests {
     @Test
     public void prefixExpression() {
         String output = serialize(not(
-            reference(var(TestIds.ANY_ID, "x", BooleanValue.REF))));
+            reference(var(TestIds.ANY_ID, "x", Types.BOOLEAN))));
         assertEquals("!x", output);
     }
 
@@ -360,7 +359,7 @@ public class CsharpSerializerTests {
 
     @Test
     public void interfaceWithMethod() {
-        MethodNode method = MethodNode.builder("get").isAbstract().returns(IntegerValue.REF).build();
+        MethodNode method = MethodNode.builder("get").isAbstract().returns(Types.INT).build();
         Node node = new ClassNodeBuilder(ScalarType.of("com.example.Example"))
             .method(method)
             .buildInterface();
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/ExpressionReadingTests.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/ExpressionReadingTests.java
index cc36c20..3ad255b 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/ExpressionReadingTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/ExpressionReadingTests.java
@@ -3,10 +3,7 @@ package org.zwobble.couscous.tests.frontends.java;
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.types.ScalarType;
-import org.zwobble.couscous.values.BooleanValue;
-import org.zwobble.couscous.values.IntegerValue;
-import org.zwobble.couscous.values.ObjectValues;
-import org.zwobble.couscous.values.StringValue;
+import org.zwobble.couscous.types.Types;
 
 import java.util.List;
 
@@ -38,7 +35,7 @@ public class ExpressionReadingTests {
         assertEquals(literal(false), readBooleanExpression("false"));
         assertEquals(literal(42), readIntExpression("42"));
         assertEquals(literal('h'), readIntExpression("'h'"));
-        assertEquals(literal(StringValue.REF), readExpression("Class<String>", "String.class"));
+        assertEquals(literal(Types.STRING), readExpression("Class<String>", "String.class"));
     }
 
     @Test
@@ -51,7 +48,7 @@ public class ExpressionReadingTests {
     @Test
     public void canReadCasts() {
         assertEquals(
-            cast(literal(42), ObjectValues.OBJECT),
+            cast(literal(42), Types.OBJECT),
             readExpression("Object", "(Object)42"));
     }
     @Test
@@ -96,7 +93,7 @@ public class ExpressionReadingTests {
             fieldAccess(
                 thisReference(ScalarType.of("com.example.Example")),
                 "name",
-                StringValue.REF),
+                Types.STRING),
             returnNode.getValue());
     }
 
@@ -122,21 +119,21 @@ public class ExpressionReadingTests {
             fieldAccess(
                 ScalarType.of("com.example.Example"),
                 "name",
-                StringValue.REF),
+                Types.STRING),
             returnNode.getValue());
     }
 
     @Test
     public void canReadInstanceMethodCalls() {
         assertEquals(
-            methodCall(literal("hello"), "startsWith", list(literal("h")), BooleanValue.REF),
+            methodCall(literal("hello"), "startsWith", list(literal("h")), Types.BOOLEAN),
             readBooleanExpression("\"hello\".startsWith(\"h\")"));
 
         List<StatementNode> statements = readStatements("int", "Object x = 1; return x.hashCode();");
         LocalVariableDeclarationNode declaration = (LocalVariableDeclarationNode) statements.get(0);
         ReturnNode returnNode = (ReturnNode) statements.get(1);
         assertEquals(
-            methodCall(reference(declaration), "hashCode", list(), IntegerValue.REF),
+            methodCall(reference(declaration), "hashCode", list(), Types.INT),
             returnNode.getValue());
     }
 
@@ -153,7 +150,7 @@ public class ExpressionReadingTests {
                 ThisReferenceNode.thisReference(ScalarType.of("com.example.Example")),
                 "loop",
                 list(),
-                StringValue.REF),
+                Types.STRING),
             returnNode.getValue());
     }
 
@@ -164,7 +161,7 @@ public class ExpressionReadingTests {
                 ScalarType.of("java.lang.Integer"),
                 "parseInt",
                 list(literal("42")),
-                IntegerValue.REF),
+                Types.INT),
             readIntExpression("Integer.parseInt(\"42\")"));
     }
 
@@ -181,7 +178,7 @@ public class ExpressionReadingTests {
                 ScalarType.of("com.example.Example"),
                 "loop",
                 list(),
-                StringValue.REF),
+                Types.STRING),
             returnNode.getValue());
     }
 
@@ -198,7 +195,7 @@ public class ExpressionReadingTests {
             "String",
             "java.util.Objects.toString(42)");
         assertEquals(
-            typeCoercion(literal(42), ObjectValues.OBJECT),
+            typeCoercion(literal(42), Types.OBJECT),
             expression.getArguments().get(0));
     }
 
@@ -285,14 +282,14 @@ public class ExpressionReadingTests {
     public void equalityOperatorDoesNotUnboxIfBothOperandsAreBoxed() {
         assertEquals(
             same(
-                typeCoercion(constructorCall(ObjectValues.BOXED_INT, list(literal(1))), ObjectValues.OBJECT),
-                typeCoercion(constructorCall(ObjectValues.BOXED_INT, list(literal(2))), ObjectValues.OBJECT)),
+                typeCoercion(constructorCall(Types.BOXED_INT, list(literal(1))), Types.OBJECT),
+                typeCoercion(constructorCall(Types.BOXED_INT, list(literal(2))), Types.OBJECT)),
             readBooleanExpression("new Integer(1) == new Integer(2)"));
 
         assertEquals(
             not(same(
-                typeCoercion(constructorCall(ObjectValues.BOXED_INT, list(literal(1))), ObjectValues.OBJECT),
-                typeCoercion(constructorCall(ObjectValues.BOXED_INT, list(literal(2))), ObjectValues.OBJECT))),
+                typeCoercion(constructorCall(Types.BOXED_INT, list(literal(1))), Types.OBJECT),
+                typeCoercion(constructorCall(Types.BOXED_INT, list(literal(2))), Types.OBJECT))),
             readBooleanExpression("new Integer(1) != new Integer(2)"));
     }
 
@@ -326,7 +323,7 @@ public class ExpressionReadingTests {
                 fieldAccess(
                     thisReference(ScalarType.of("com.example.Example")),
                     "name",
-                    StringValue.REF),
+                    Types.STRING),
                 literal("blah")),
             returnNode.getValue());
     }
@@ -345,8 +342,8 @@ public class ExpressionReadingTests {
                 fieldAccess(
                     thisReference(ScalarType.of("com.example.Example")),
                     "value",
-                    ObjectValues.OBJECT),
-                typeCoercion(literal(4), ObjectValues.OBJECT)),
+                    Types.OBJECT),
+                typeCoercion(literal(4), Types.OBJECT)),
             returnNode.getValue());
     }
 
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/FreeVariablesTests.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/FreeVariablesTests.java
index 84e9508..8bcf38d 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/FreeVariablesTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/FreeVariablesTests.java
@@ -4,11 +4,10 @@ import org.junit.Test;
 import org.zwobble.couscous.ast.ReferenceNode;
 import org.zwobble.couscous.ast.VariableDeclaration;
 import org.zwobble.couscous.tests.TestIds;
-import org.zwobble.couscous.values.StringValue;
+import org.zwobble.couscous.types.Types;
 
 import java.util.List;
 
-import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
 import static org.junit.Assert.assertEquals;
 import static org.zwobble.couscous.ast.FormalArgumentNode.formalArg;
@@ -22,14 +21,14 @@ import static org.zwobble.couscous.util.ExtraLists.list;
 public class FreeVariablesTests {
     @Test
     public void referenceIsFreeIfThereIsNoAssociatedDeclaration() {
-        VariableDeclaration declaration = var(TestIds.ANY_ID, "[name]", StringValue.REF);
+        VariableDeclaration declaration = var(TestIds.ANY_ID, "[name]", Types.STRING);
         List<ReferenceNode> freeVariables = findFreeVariables(list(reference(declaration)));
         assertEquals(list(reference(declaration)), freeVariables);
     }
 
     @Test
     public void referenceIsNotFreeIfIsDeclaredAsArgument() {
-        VariableDeclaration declaration = var(TestIds.ANY_ID, "[name]", StringValue.REF);
+        VariableDeclaration declaration = var(TestIds.ANY_ID, "[name]", Types.STRING);
         List<ReferenceNode> freeVariables = findFreeVariables(
             list(formalArg(declaration), reference(declaration)));
         assertEquals(emptyList(), freeVariables);
@@ -37,7 +36,7 @@ public class FreeVariablesTests {
 
     @Test
     public void referenceIsNotFreeIfIsReferenceToLocalDefinedInBody() {
-        VariableDeclaration declaration = var(TestIds.ANY_ID, "[name]", StringValue.REF);
+        VariableDeclaration declaration = var(TestIds.ANY_ID, "[name]", Types.STRING);
         List<ReferenceNode> freeVariables = findFreeVariables(
             list(
                 localVariableDeclaration(declaration, literal("[value]")),
diff --git a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
index c3b83a0..97b8b66 100644
--- a/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/frontends/java/JavaReaderTests.java
@@ -3,9 +3,7 @@ package org.zwobble.couscous.tests.frontends.java;
 import org.junit.Test;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.types.ScalarType;
-import org.zwobble.couscous.values.IntegerValue;
-import org.zwobble.couscous.values.ObjectValues;
-import org.zwobble.couscous.values.StringValue;
+import org.zwobble.couscous.types.Types;
 
 import java.util.List;
 
@@ -41,7 +39,7 @@ public class JavaReaderTests {
         
         LocalVariableDeclarationNode declaration = (LocalVariableDeclarationNode) statements.get(0);
         assertEquals("x", declaration.getName());
-        assertEquals(IntegerValue.REF, declaration.getType());
+        assertEquals(Types.INT, declaration.getType());
         assertEquals(literal(4), declaration.getInitialValue());
         ReturnNode returnNode = (ReturnNode) statements.get(1);
         assertEquals(
@@ -54,7 +52,7 @@ public class JavaReaderTests {
         StatementNode statement = readStatement("void", "Object x = 4;");
         
         LocalVariableDeclarationNode declaration = (LocalVariableDeclarationNode) statement;
-        assertEquals(typeCoercion(literal(4), ObjectValues.OBJECT), declaration.getInitialValue());
+        assertEquals(typeCoercion(literal(4), Types.OBJECT), declaration.getInitialValue());
     }
 
     @Test
@@ -65,7 +63,7 @@ public class JavaReaderTests {
             "}");
 
         MethodNode method = classNode.getMethods().get(0);
-        assertEquals(IntegerValue.REF, method.getReturnType());
+        assertEquals(Types.INT, method.getReturnType());
     }
     
     @Test
@@ -93,7 +91,7 @@ public class JavaReaderTests {
                     ScalarType.of("java.lang.Integer"),
                     "parseInt",
                     list(literal("42")),
-                    IntegerValue.REF)),
+                    Types.INT)),
             readStatement("void", "Integer.parseInt(\"42\");"));
     }
     
@@ -182,7 +180,7 @@ public class JavaReaderTests {
                 fieldAccess(
                     thisReference(ScalarType.of("com.example.Example")),
                     "name",
-                    StringValue.REF),
+                    Types.STRING),
                 literal("Flaws"))),
             constructor.getBody());
     }
@@ -205,13 +203,13 @@ public class JavaReaderTests {
                     fieldAccess(
                         thisReference(ScalarType.of("com.example.Example")),
                         "year",
-                        IntegerValue.REF),
+                        Types.INT),
                     literal(2013)),
                 assignStatement(
                     fieldAccess(
                         thisReference(ScalarType.of("com.example.Example")),
                         "name",
-                        StringValue.REF),
+                        Types.STRING),
                     literal("Flaws"))),
             constructor.getBody());
     }
@@ -233,13 +231,13 @@ public class JavaReaderTests {
                     fieldAccess(
                         thisReference(ScalarType.of("com.example.Example")),
                         "year",
-                        IntegerValue.REF),
+                        Types.INT),
                     literal(2013)),
                 assignStatement(
                     fieldAccess(
                         thisReference(ScalarType.of("com.example.Example")),
                         "name",
-                        StringValue.REF),
+                        Types.STRING),
                     literal("Flaws"))),
             constructor.getBody());
     }
@@ -259,7 +257,7 @@ public class JavaReaderTests {
                 fieldAccess(
                     ScalarType.of("com.example.Example"),
                     "name",
-                    StringValue.REF),
+                    Types.STRING),
                 literal("Flaws"))),
             staticConstructor);
     }
@@ -276,7 +274,7 @@ public class JavaReaderTests {
                 fieldAccess(
                     ScalarType.of("com.example.Example"),
                     "name",
-                    StringValue.REF),
+                    Types.STRING),
                 literal("Flaws"))),
             staticConstructor);
     }
@@ -362,7 +360,7 @@ public class JavaReaderTests {
 
         MethodNode expectedMethod = MethodNode.builder("get")
             .isAbstract()
-            .returns(IntegerValue.REF)
+            .returns(Types.INT)
             .build();
         assertEquals(list(expectedMethod), classNode.getMethods());
     }
diff --git a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
index 760cc56..6112c8e 100644
--- a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
@@ -13,10 +13,8 @@ import org.zwobble.couscous.interpreter.values.IntegerInterpreterValue;
 import org.zwobble.couscous.interpreter.values.InterpreterValue;
 import org.zwobble.couscous.interpreter.values.StringInterpreterValue;
 import org.zwobble.couscous.tests.BackendEvalTests;
-import org.zwobble.couscous.values.IntegerValue;
-import org.zwobble.couscous.values.ObjectValues;
+import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.values.PrimitiveValue;
-import org.zwobble.couscous.values.StringValue;
 
 import java.util.List;
 import java.util.Optional;
@@ -41,7 +39,7 @@ import static org.zwobble.couscous.util.ExtraLists.list;
 public class EvaluatorTests extends BackendEvalTests {
     @Test
     public void valueOfAssignmentExpressionIsNewValue() {
-        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", StringValue.REF));
+        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", Types.STRING));
         Environment environment = new Environment(
             new MapBackedProject(ImmutableMap.of()),
             Optional.empty(),
@@ -66,8 +64,8 @@ public class EvaluatorTests extends BackendEvalTests {
                     literal("hello"),
                     "size",
                     list(),
-                    IntegerValue.REF)));
-        assertEquals(new MethodSignature("size", list(), IntegerValue.REF), exception.getSignature());
+                    Types.INT)));
+        assertEquals(new MethodSignature("size", list(), Types.INT), exception.getSignature());
     }
     
     @Test
@@ -78,8 +76,8 @@ public class EvaluatorTests extends BackendEvalTests {
                     literal("hello"),
                     "substring",
                     list(literal(1)),
-                    StringValue.REF)));
-        assertEquals(new MethodSignature("substring", list(IntegerValue.REF), StringValue.REF), exception.getSignature());
+                    Types.STRING)));
+        assertEquals(new MethodSignature("substring", list(Types.INT), Types.STRING), exception.getSignature());
     }
     
     @Test
@@ -90,15 +88,15 @@ public class EvaluatorTests extends BackendEvalTests {
                     literal("hello"),
                     "substring",
                     list(literal(0), literal("")),
-                    StringValue.REF)));
+                    Types.STRING)));
         assertEquals(
-            new MethodSignature("substring", list(IntegerValue.REF, StringValue.REF), StringValue.REF),
+            new MethodSignature("substring", list(Types.INT, Types.STRING), Types.STRING),
             exception.getSignature());
     }
 
     @Test
     public void errorIfConstructorArgumentIsWrongType() {
-        FormalArgumentNode argument = formalArg(var(ANY_ID, "x", IntegerValue.REF));
+        FormalArgumentNode argument = formalArg(var(ANY_ID, "x", Types.INT));
         ClassNode classNode = ClassNode.builder("com.example.Example")
             .constructor(constructor -> constructor
                 .argument(argument))
@@ -111,7 +109,7 @@ public class EvaluatorTests extends BackendEvalTests {
                     classNode.getName(),
                     list(literal("")))));
 
-        assertEquals(new UnexpectedValueType(IntegerValue.REF, StringValue.REF), exception);
+        assertEquals(new UnexpectedValueType(Types.INT, Types.STRING), exception);
     }
 
     @Test
@@ -127,7 +125,7 @@ public class EvaluatorTests extends BackendEvalTests {
                         classNode.getName(),
                         list()),
                     "value",
-                    IntegerValue.REF)));
+                    Types.INT)));
         
         assertEquals(new NoSuchField("value"), exception);
     }
@@ -135,7 +133,7 @@ public class EvaluatorTests extends BackendEvalTests {
     @Test
     public void cannotGetValueOfUnboundField() {
         ClassNode classNode = ClassNode.builder("com.example.Example")
-            .field("value", IntegerValue.REF)
+            .field("value", Types.INT)
             .build();
         
         UnboundField exception = assertThrows(UnboundField.class,
@@ -146,7 +144,7 @@ public class EvaluatorTests extends BackendEvalTests {
                         classNode.getName(),
                         list()),
                     "value",
-                    IntegerValue.REF)));
+                    Types.INT)));
         
         assertEquals(new UnboundField("value"), exception);
     }
@@ -156,7 +154,7 @@ public class EvaluatorTests extends BackendEvalTests {
         ClassNode classNode = ClassNode.builder("com.example.Example")
             .constructor(constructor -> constructor
                 .statement(assignStatement(
-                    fieldAccess(constructor.thisReference(), "value", IntegerValue.REF),
+                    fieldAccess(constructor.thisReference(), "value", Types.INT),
                     literal(42))))
             .build();
         
@@ -174,10 +172,10 @@ public class EvaluatorTests extends BackendEvalTests {
     public void cannotSetValueOfInstanceFieldAsThoughItIsAStaticField() {
         ScalarType type = ScalarType.of("com.example.Example");
         ClassNode classNode = ClassNode.builder(type)
-            .field("value", IntegerValue.REF)
+            .field("value", Types.INT)
             .constructor(constructor -> constructor
                 .statement(assignStatement(
-                    fieldAccess(type, "value", IntegerValue.REF),
+                    fieldAccess(type, "value", Types.INT),
                     literal(42))))
             .build();
 
@@ -194,10 +192,10 @@ public class EvaluatorTests extends BackendEvalTests {
     @Test
     public void cannotSetValueOfFieldWithWrongType() {
         ClassNode classNode = ClassNode.builder("com.example.Example")
-            .field("value", IntegerValue.REF)
+            .field("value", Types.INT)
             .constructor(constructor -> constructor
                 .statement(assignStatement(
-                    fieldAccess(constructor.thisReference(), "value", IntegerValue.REF),
+                    fieldAccess(constructor.thisReference(), "value", Types.INT),
                     literal(""))))
             .build();
         
@@ -208,14 +206,14 @@ public class EvaluatorTests extends BackendEvalTests {
                     classNode.getName(),
                     list())));
         
-        assertEquals(new UnexpectedValueType(IntegerValue.REF, StringValue.REF), exception);
+        assertEquals(new UnexpectedValueType(Types.INT, Types.STRING), exception);
     }
 
     @Test
     public void validCastPassesValueThrough() {
         InterpreterValue value = eval(
             emptyEnvironment(),
-            cast(literal("42"), ObjectValues.OBJECT));
+            cast(literal("42"), Types.OBJECT));
         assertEquals(value("42"), value);
     }
 
@@ -223,9 +221,9 @@ public class EvaluatorTests extends BackendEvalTests {
     public void errorIfCastIsNotValid() {
         InvalidCast exception = assertThrows(InvalidCast.class,
             () -> eval(emptyEnvironment(),
-                cast(literal(42), StringValue.REF)));
-        assertEquals(StringValue.REF, exception.getExpected());
-        assertEquals(IntegerValue.REF, exception.getActual());
+                cast(literal(42), Types.STRING)));
+        assertEquals(Types.STRING, exception.getExpected());
+        assertEquals(Types.INT, exception.getActual());
     }
     
     private static Environment emptyEnvironment() {
diff --git a/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java b/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java
index 9787ee2..0e644e1 100644
--- a/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/InterpreterMethodTests.java
@@ -15,10 +15,8 @@ import org.zwobble.couscous.interpreter.values.InterpreterValue;
 import org.zwobble.couscous.interpreter.values.InterpreterValues;
 import org.zwobble.couscous.tests.BackendMethodTests;
 import org.zwobble.couscous.tests.MethodRunner;
-import org.zwobble.couscous.values.IntegerValue;
+import org.zwobble.couscous.types.Types;
 import org.zwobble.couscous.values.PrimitiveValue;
-import org.zwobble.couscous.values.StringValue;
-import org.zwobble.couscous.values.UnitValue;
 
 import java.util.List;
 import java.util.stream.Collectors;
@@ -46,12 +44,12 @@ public class InterpreterMethodTests extends BackendMethodTests {
         NoSuchMethod exception = assertThrows(NoSuchMethod.class,
             () -> runMethod(method, value("hello, world!")));
         
-        assertEquals(new MethodSignature("hello", list(StringValue.REF), UnitValue.REF), exception.getSignature());
+        assertEquals(new MethodSignature("hello", list(Types.STRING), Types.VOID), exception.getSignature());
     }
     
     @Test
     public void errorIfTryingToAssignValueOfWrongTypeToVariable() {
-        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", StringValue.REF));
+        FormalArgumentNode arg = formalArg(var(ANY_ID, "x", Types.STRING));
         MethodNode.Builder method = staticMethod("hello")
             .argument(arg)
             .statement(expressionStatement(assign(reference(arg), literal(0))));
@@ -59,13 +57,13 @@ public class InterpreterMethodTests extends BackendMethodTests {
         UnexpectedValueType exception = assertThrows(UnexpectedValueType.class,
             () -> runMethod(method, value("")));
         
-        assertEquals(new UnexpectedValueType(StringValue.REF, IntegerValue.REF), exception);
+        assertEquals(new UnexpectedValueType(Types.STRING, Types.INT), exception);
     }
     
     @Test
     public void errorIfTryingToAssignToVariableNotInScope() {
         LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(
-            ANY_ID, "x", StringValue.REF, literal(""));
+            ANY_ID, "x", Types.STRING, literal(""));
         MethodNode.Builder method = staticMethod("hello")
             .statement(expressionStatement(assign(reference(localVariableDeclaration), LiteralNode.literal("[updated value]"))));
 
@@ -78,7 +76,7 @@ public class InterpreterMethodTests extends BackendMethodTests {
     @Test
     public void errorIfTryingToGetValueOfVariableNotInScope() {
         LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(
-            ANY_ID, "x", StringValue.REF, literal(""));
+            ANY_ID, "x", Types.STRING, literal(""));
         MethodNode.Builder method = staticMethod("hello")
             .statement(returns(reference(localVariableDeclaration)));
 
@@ -91,7 +89,7 @@ public class InterpreterMethodTests extends BackendMethodTests {
     @Test
     public void errorIfTryingToGetValueOfUnboundVariable() {
         LocalVariableDeclarationNode localVariableDeclaration = localVariableDeclaration(
-            ANY_ID, "x", StringValue.REF, literal(""));
+            ANY_ID, "x", Types.STRING, literal(""));
         MethodNode.Builder method = staticMethod("hello")
             .statement(returns(reference(localVariableDeclaration)))
             .statement(localVariableDeclaration);