Add ConstructedType

3 files changed, 22 insertions, 1 deletions

diff --git a/src/main/java/org/shedlang/compiler/types/ConstructedType.java b/src/main/java/org/shedlang/compiler/types/ConstructedType.java
new file mode 100644
index 00000000..558b227b
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/types/ConstructedType.java
@@ -0,0 +1,17 @@
+package org.shedlang.compiler.types;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public record ConstructedType<T extends StructuredType>(
+    TypeConstructor<T> constructor,
+    List<Type> args
+) implements Type {
+    @Override
+    public String describe() {
+        var argsString = args.stream()
+            .map(arg -> arg.describe())
+            .collect(Collectors.joining(", "));
+        return constructor.describe() + "[" + argsString + "]";
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/types/Type.java b/src/main/java/org/shedlang/compiler/types/Type.java
index 8ec577bf..9a062156 100644
--- a/src/main/java/org/shedlang/compiler/types/Type.java
+++ b/src/main/java/org/shedlang/compiler/types/Type.java
@@ -6,5 +6,5 @@ package org.shedlang.compiler.types;
  * found through auxiliary data.
  */
 public sealed interface Type extends TypeLevelValue
-    permits BoolType, BottomType, FunctionType, IntType, NamespaceType, StringType, StructuredType, SumType, TopType, TupleType, TypeLevelValueType, TypeParam, UnitType {
+    permits BoolType, BottomType, ConstructedType, FunctionType, IntType, NamespaceType, StringType, StructuredType, SumType, TopType, TupleType, TypeLevelValueType, TypeParam, UnitType {
 }
diff --git a/src/main/java/org/shedlang/compiler/types/TypeParam.java b/src/main/java/org/shedlang/compiler/types/TypeParam.java
index 240d701d..702d6a5f 100644
--- a/src/main/java/org/shedlang/compiler/types/TypeParam.java
+++ b/src/main/java/org/shedlang/compiler/types/TypeParam.java
@@ -1,6 +1,10 @@
 package org.shedlang.compiler.types;
 
 public record TypeParam(Scope scope, String name) implements Type {
+    public static TypeParam forStructType(StructType structType, String name) {
+        return new TypeParam(new Scope.Struct(structType), name);
+    }
+
     @Override
     public String describe() {
         return name;