Add Bool and Int types

7 files changed, 90 insertions, 2 deletions

diff --git a/src/main/java/org/shedlang/compiler/types/BoolType.java b/src/main/java/org/shedlang/compiler/types/BoolType.java
new file mode 100644
index 00000000..8bf9ed25
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/types/BoolType.java
@@ -0,0 +1,18 @@
+package org.shedlang.compiler.types;
+
+public final class BoolType implements Type {
+    private BoolType() {
+    }
+
+    static final BoolType INSTANCE = new BoolType();
+
+    @Override
+    public String describe() {
+        return "Bool";
+    }
+
+    @Override
+    public String toString() {
+        return describe();
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/types/FunctionType.java b/src/main/java/org/shedlang/compiler/types/FunctionType.java
index 07505821..ad0f56d3 100644
--- a/src/main/java/org/shedlang/compiler/types/FunctionType.java
+++ b/src/main/java/org/shedlang/compiler/types/FunctionType.java
@@ -1,9 +1,38 @@
 package org.shedlang.compiler.types;
 
+import org.pcollections.Empty;
+import org.pcollections.PVector;
+
 import java.util.List;
 
 public record FunctionType(
     List<Type> positionalArgs,
     Type returnType
 ) implements Type {
+    public static Builder builder() {
+        return new Builder(Empty.vector(), Types.UNIT);
+    }
+
+    @Override
+    public String describe() {
+        // TODO: implement this sensibly
+        return toString();
+    }
+
+    public record Builder(
+        PVector<Type> positionalParams,
+        Type returnType
+    ) {
+        public FunctionType build() {
+            return new FunctionType(positionalParams, returnType);
+        }
+
+        public Builder addPositionalParam(Type param) {
+            return new Builder(positionalParams.plus(param), returnType);
+        }
+
+        public Builder withReturnType(Type returnType) {
+            return new Builder(positionalParams, returnType);
+        }
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/types/IntType.java b/src/main/java/org/shedlang/compiler/types/IntType.java
new file mode 100644
index 00000000..01faa16f
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/types/IntType.java
@@ -0,0 +1,18 @@
+package org.shedlang.compiler.types;
+
+public final class IntType implements Type {
+    private IntType() {
+    }
+
+    static final IntType INSTANCE = new IntType();
+
+    @Override
+    public String describe() {
+        return "Int";
+    }
+
+    @Override
+    public String toString() {
+        return describe();
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/types/StringType.java b/src/main/java/org/shedlang/compiler/types/StringType.java
index 9b4351cd..eb2374a3 100644
--- a/src/main/java/org/shedlang/compiler/types/StringType.java
+++ b/src/main/java/org/shedlang/compiler/types/StringType.java
@@ -5,4 +5,14 @@ public final class StringType implements Type {
 
     private StringType() {
     }
+
+    @Override
+    public String describe() {
+        return "String";
+    }
+
+    @Override
+    public String toString() {
+        return describe();
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/types/Type.java b/src/main/java/org/shedlang/compiler/types/Type.java
index 267fdcb8..5077776c 100644
--- a/src/main/java/org/shedlang/compiler/types/Type.java
+++ b/src/main/java/org/shedlang/compiler/types/Type.java
@@ -1,4 +1,5 @@
 package org.shedlang.compiler.types;
 
-public sealed interface Type permits FunctionType, StringType, UnitType {
+public sealed interface Type permits BoolType, FunctionType, IntType, StringType, UnitType {
+    String describe();
 }
diff --git a/src/main/java/org/shedlang/compiler/types/Types.java b/src/main/java/org/shedlang/compiler/types/Types.java
index 0151f7ad..9655d2bb 100644
--- a/src/main/java/org/shedlang/compiler/types/Types.java
+++ b/src/main/java/org/shedlang/compiler/types/Types.java
@@ -4,6 +4,8 @@ public class Types {
     private Types() {
     }
 
+    public static final Type BOOL = BoolType.INSTANCE;
+    public static final Type INT = IntType.INSTANCE;
     public static final Type STRING = StringType.INSTANCE;
     public static final Type UNIT = UnitType.INSTANCE;
 }
diff --git a/src/main/java/org/shedlang/compiler/types/UnitType.java b/src/main/java/org/shedlang/compiler/types/UnitType.java
index a84b66bd..acc7aad0 100644
--- a/src/main/java/org/shedlang/compiler/types/UnitType.java
+++ b/src/main/java/org/shedlang/compiler/types/UnitType.java
@@ -1,8 +1,18 @@
 package org.shedlang.compiler.types;
 
 public final class UnitType implements Type {
+    static final UnitType INSTANCE = new UnitType();
+
     private UnitType() {
     }
 
-    static final UnitType INSTANCE = new UnitType();
+    @Override
+    public String describe() {
+        return "Unit";
+    }
+
+    @Override
+    public String toString() {
+        return describe();
+    }
 }