Type check function definition params

2 files changed, 53 insertions, 4 deletions

diff --git a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionDefinitionNode.java b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionDefinitionNode.java
index 1292c029..57c02568 100644
--- a/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionDefinitionNode.java
+++ b/src/main/java/org/shedlang/compiler/ast/untyped/UntypedFunctionDefinitionNode.java
@@ -57,6 +57,28 @@ public record UntypedFunctionDefinitionNode(
             );
         }
 
+        public Builder addPositionalParam(String name, UntypedTypeLevelExpressionNode type) {
+            return new Builder(
+                name,
+                positionalParams.plus(new UntypedParamNode(name, type, Sources.NULL)),
+                namedParams,
+                effect,
+                returnType,
+                body
+            );
+        }
+
+        public Builder addNamedParam(String name, UntypedTypeLevelExpressionNode type) {
+            return new Builder(
+                name,
+                positionalParams,
+                namedParams.plus(new UntypedParamNode(name, type, Sources.NULL)),
+                effect,
+                returnType,
+                body
+            );
+        }
+
         public Builder withReturnType(UntypedTypeLevelExpressionNode returnType) {
             return new Builder(
                 name,
diff --git a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
index f5d3f728..c6875d1b 100644
--- a/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/shedlang/compiler/typechecker/TypeChecker.java
@@ -12,7 +12,6 @@ import org.shedlang.compiler.types.TypeLevelValue;
 import org.shedlang.compiler.types.TypeLevelValueType;
 
 import java.util.HashSet;
-import java.util.List;
 import java.util.Optional;
 
 public class TypeChecker {
@@ -168,18 +167,20 @@ public class TypeChecker {
         UntypedFunctionDefinitionNode untyped,
         TypeCheckerContext context
     ) {
+        var typedParams = typeCheckParams(untyped.params(), context);
+
         var typedReturnType = typeCheckTypeLevelExpression(TypeSets.META_TYPE, untyped.returnType(), context);
 
-        var body = untyped.body().stream()
+        var typedBody = untyped.body().stream()
             .map(statement -> typeCheckFunctionStatement(statement, context))
             .toList();
 
         return new TypedFunctionDefinitionNode(
             untyped.name(),
-            new TypedParamsNode(List.of(), List.of(), untyped.params().source()),
+            typedParams,
             Optional.empty(),
             typedReturnType,
-            body,
+            typedBody,
             untyped.source()
         );
     }
@@ -213,6 +214,32 @@ public class TypeChecker {
         };
     }
 
+    private static TypedParamNode typeCheckParam(
+        UntypedParamNode untyped,
+        TypeCheckerContext context
+    ) {
+        return new TypedParamNode(
+            untyped.name(),
+            typeCheckTypeLevelExpression(TypeSets.META_TYPE, untyped.type(), context),
+            untyped.source()
+        );
+    }
+
+    private static TypedParamsNode typeCheckParams(
+        UntypedParamsNode untyped,
+        TypeCheckerContext context
+    ) {
+        var typedPositional = untyped.positional().stream()
+            .map(param -> typeCheckParam(param, context))
+            .toList();
+
+        var typedNamed = untyped.named().stream()
+            .map(param -> typeCheckParam(param, context))
+            .toList();
+
+        return new TypedParamsNode(typedPositional, typedNamed, untyped.source());
+    }
+
     private static TypedReferenceNode typeCheckReference(
         UntypedReferenceNode untyped,
         TypeCheckerContext context