Check for reference before definition

6 files changed, 61 insertions, 35 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
index d0351d70..6f1c5c99 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerCallTests.java
@@ -30,7 +30,7 @@ public class TypeCheckerCallTests {
             .withReturnType(Types.STRING)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var typed = TypeChecker.typeCheckExpression(untyped, context);
 
@@ -51,7 +51,7 @@ public class TypeCheckerCallTests {
             List.of()
         );
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", Types.STRING)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", Types.STRING)));
 
         var error = assertThrows(
             UnexpectedTypeError.class,
@@ -76,7 +76,7 @@ public class TypeCheckerCallTests {
             .addPositionalParam(Types.INT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var typed = TypeChecker.typeCheckExpression(untyped, context);
 
@@ -105,7 +105,7 @@ public class TypeCheckerCallTests {
             .addNamedParam("y", Types.INT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var typed = TypeChecker.typeCheckExpression(untyped, context);
 
@@ -131,7 +131,7 @@ public class TypeCheckerCallTests {
             .addPositionalParam(Types.INT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             UnexpectedTypeError.class,
@@ -155,7 +155,7 @@ public class TypeCheckerCallTests {
             .addNamedParam("x", Types.INT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             UnexpectedTypeError.class,
@@ -177,7 +177,7 @@ public class TypeCheckerCallTests {
         var functionType = FunctionType.builder()
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             WrongNumberOfPositionalArgsError.class,
@@ -199,7 +199,7 @@ public class TypeCheckerCallTests {
             .addNamedParam("x", Types.STRING)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             MissingNamedArgError.class,
@@ -221,7 +221,7 @@ public class TypeCheckerCallTests {
         var functionType = FunctionType.builder()
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             UnexpectedNamedArgError.class,
@@ -245,7 +245,7 @@ public class TypeCheckerCallTests {
             .addNamedParam("x", Types.STRING)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             CannotPassNamedArgTwiceError.class,
@@ -266,7 +266,7 @@ public class TypeCheckerCallTests {
             .withReturnType(Types.UNIT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         var error = assertThrows(
             CallIsMissingEffectsError.class,
@@ -287,7 +287,7 @@ public class TypeCheckerCallTests {
             .withReturnType(Types.UNIT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("f", functionType)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("f", functionType)));
 
         assertThrows(
             FunctionHasNoEffectsError.class,
@@ -306,7 +306,10 @@ public class TypeCheckerCallTests {
             .withReturnType(Types.UNIT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterFunction(P.map(Map.entry("f", functionType)), Effects.IO);
+            .enterFunction(
+                P.map(Map.entry("f", TypeCheckerContext.defined(functionType))),
+                Effects.IO
+            );
 
         var typed = TypeChecker.typeCheckExpression(untyped, context);
 
@@ -329,7 +332,10 @@ public class TypeCheckerCallTests {
             .withReturnType(Types.UNIT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterFunction(P.map(Map.entry("f", functionType)), Effects.NONE);
+            .enterFunction(
+                P.map(Map.entry("f", TypeCheckerContext.defined(functionType))),
+                Effects.NONE
+            );
 
         var error = assertThrows(
             UnexpectedEffectError.class,
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionDefinitionTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionDefinitionTests.java
index c62efde7..31f80f9b 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionDefinitionTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionDefinitionTests.java
@@ -25,7 +25,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .withReturnType(Untyped.typeLevelReference("Unit"))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
 
         var typed = TypeChecker.typeCheckNamespaceStatement(untyped, context);
 
@@ -49,7 +49,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .withReturnType(Untyped.typeLevelReference("Unit"))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("Int", Types.metaType(Types.INT)),
                 Map.entry("String", Types.metaType(Types.STRING)),
                 Map.entry("Unit", Types.metaType(Types.UNIT))
@@ -82,7 +82,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .withReturnType(Untyped.typeLevelReference("Unit"))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("Io", Types.effectType(Effects.IO)),
                 Map.entry("Unit", Types.metaType(Types.UNIT))
             ));
@@ -103,7 +103,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .addStatement(Untyped.expressionStatement(Untyped.stringLiteral("hello")))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
 
         var typed = TypeChecker.typeCheckNamespaceStatement(untyped, context);
 
@@ -124,7 +124,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .addStatement(Untyped.expressionStatement(Untyped.reference("x")))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("String", Types.metaType(Types.STRING)),
                 Map.entry("Unit", Types.metaType(Types.UNIT))
             ));
@@ -148,7 +148,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .addStatement(Untyped.expressionStatement(Untyped.reference("x")))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("String", Types.metaType(Types.STRING)),
                 Map.entry("Unit", Types.metaType(Types.UNIT))
             ));
@@ -181,7 +181,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .withReturnType(Types.UNIT)
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("f", functionType),
                 Map.entry("Io", Types.effectType(Effects.IO)),
                 Map.entry("Unit", Types.metaType(Types.UNIT))
@@ -205,7 +205,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .addStatement(Untyped.expressionStatement(Untyped.reference("y")))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("Unit", Types.metaType(Types.UNIT)),
                 Map.entry("x", Types.STRING),
                 Map.entry("y", Types.STRING)
@@ -230,7 +230,7 @@ public class TypeCheckerFunctionDefinitionTests {
             .addStatement(Untyped.expressionStatement(Untyped.reference("x")))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("String", Types.metaType(Types.STRING)),
                 Map.entry("Unit", Types.metaType(Types.UNIT))
             ));
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNamespaceTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNamespaceTests.java
index 9ed2e837..c4851b13 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNamespaceTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerNamespaceTests.java
@@ -20,7 +20,7 @@ public class TypeCheckerNamespaceTests {
     public void canTypeCheckEmptyNamespace() {
         var untyped = Untyped.namespace(List.of());
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
 
         var result = TypeChecker.typeCheckNamespace(untyped, context);
 
@@ -39,7 +39,7 @@ public class TypeCheckerNamespaceTests {
                 .build()
         ));
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
 
         var result = TypeChecker.typeCheckNamespace(untyped, context);
 
@@ -67,7 +67,7 @@ public class TypeCheckerNamespaceTests {
             )
         );
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Unit", Types.metaType(Types.UNIT))));
 
         var result = TypeChecker.typeCheckNamespace(untyped, context);
 
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerReferenceTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerReferenceTests.java
index 317dbd02..14440354 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerReferenceTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerReferenceTests.java
@@ -18,7 +18,7 @@ public class TypeCheckerReferenceTests {
     public void whenNameIsBoundInEnvironmentThenTypeIsUsedFromEnvironment() {
         var untyped = Untyped.reference("x");
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("x", Types.STRING)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("x", Types.STRING)));
 
         var typed = TypeChecker.typeCheckExpression(untyped, context);
 
@@ -29,7 +29,7 @@ public class TypeCheckerReferenceTests {
     public void whenNameIsNotBoundInEnvironmentThenErrorIsThrown() {
         var untyped = Untyped.reference("x");
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("y", Types.STRING)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("y", Types.STRING)));
 
         var error = assertThrows(
             UnknownVariableError.class,
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTypeLevelReferenceTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTypeLevelReferenceTests.java
index 90337920..589f9f1d 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTypeLevelReferenceTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTypeLevelReferenceTests.java
@@ -21,7 +21,7 @@ public class TypeCheckerTypeLevelReferenceTests {
     public void whenNameIsBoundInEnvironmentThenTypeIsUsedFromEnvironment() {
         var untyped = Untyped.typeLevelReference("String");
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("String", Types.metaType(Types.STRING))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("String", Types.metaType(Types.STRING))));
 
         var typed = TypeChecker.typeCheckTypeLevelExpression(TypeSets.META_TYPE, untyped, context);
 
@@ -32,7 +32,7 @@ public class TypeCheckerTypeLevelReferenceTests {
     public void whenNameRefersToNonTypeLevelValueThenErrorIsThrown() {
         var untyped = Untyped.typeLevelReference("String");
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("String", Types.STRING)));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("String", Types.STRING)));
 
         var error = assertThrows(
             UnexpectedTypeError.class,
@@ -47,7 +47,7 @@ public class TypeCheckerTypeLevelReferenceTests {
     public void whenNameRefersToValueOfWrongTypeThenErrorIsThrown() {
         var untyped = Untyped.typeLevelReference("Io");
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Io", Types.effectType(Effects.IO))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Io", Types.effectType(Effects.IO))));
 
         var error = assertThrows(
             UnexpectedTypeError.class,
@@ -62,7 +62,7 @@ public class TypeCheckerTypeLevelReferenceTests {
     public void whenNameIsNotBoundInEnvironmentThenErrorIsThrown() {
         var untyped = Untyped.typeLevelReference("String");
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(Map.entry("Int", Types.metaType(Types.INT))));
+            .enterBlockWithDefinedVariables(P.map(Map.entry("Int", Types.metaType(Types.INT))));
 
         var error = assertThrows(
             UnknownVariableError.class,
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerValTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerValTests.java
index 8ebe4f79..1526d3aa 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerValTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerValTests.java
@@ -3,15 +3,16 @@ package org.shedlang.compiler.typechecker;
 import org.junit.jupiter.api.Test;
 import org.shedlang.compiler.ast.untyped.Untyped;
 import org.shedlang.compiler.ast.untyped.UntypedFunctionDefinitionNode;
+import org.shedlang.compiler.typechecker.errors.ReferenceBeforeDefinitionError;
 import org.shedlang.compiler.types.Types;
 import org.shedlang.compiler.util.P;
 
 import java.util.Map;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.shedlang.compiler.ast.typed.TypedNodeMatchers.*;
 import static org.zwobble.precisely.AssertThat.assertThat;
-import static org.zwobble.precisely.Matchers.anything;
-import static org.zwobble.precisely.Matchers.isSequence;
+import static org.zwobble.precisely.Matchers.*;
 
 public class TypeCheckerValTests {
     @Test
@@ -33,7 +34,7 @@ public class TypeCheckerValTests {
             .addStatement(Untyped.expressionStatement(Untyped.reference("x")))
             .build();
         var context = TypeCheckerContext.EMPTY
-            .enterBlock(P.map(
+            .enterBlockWithDefinedVariables(P.map(
                 Map.entry("Unit", Types.metaType(Types.UNIT))
             ));
 
@@ -48,4 +49,23 @@ public class TypeCheckerValTests {
                 ))
         );
     }
+
+    @Test
+    public void valCannotBeReferencedBeforeDefinition() {
+        var untyped = UntypedFunctionDefinitionNode.builder()
+            .addStatement(Untyped.expressionStatement(Untyped.reference("x")))
+            .addStatement(Untyped.val(Untyped.targetVariable("x"), Untyped.stringLiteral("hello")))
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enterBlockWithDefinedVariables(P.map(
+                Map.entry("Unit", Types.metaType(Types.UNIT))
+            ));
+
+        var error = assertThrows(
+            ReferenceBeforeDefinitionError.class,
+            () -> TypeChecker.typeCheckNamespaceStatement(untyped, context)
+        );
+
+        assertThat(error.variableName(), equalTo("x"));
+    }
 }