4 files changed, 13 insertions, 0 deletions
diff --git a/src/main/java/org/shedlang/compiler/types/BoolType.java b/src/main/java/org/shedlang/compiler/types/BoolType.java
index 8bf9ed25..0343cc24 100644
--- a/src/main/java/org/shedlang/compiler/types/BoolType.java
+++ b/src/main/java/org/shedlang/compiler/types/BoolType.java
@@ -1,5 +1,8 @@
 package org.shedlang.compiler.types;
 
+/**
+ * The {@code Bool} type, either true or false.
+ */
 public final class BoolType implements Type {
     private BoolType() {
     }
diff --git a/src/main/java/org/shedlang/compiler/types/IntType.java b/src/main/java/org/shedlang/compiler/types/IntType.java
index 01faa16f..c74b8bd2 100644
--- a/src/main/java/org/shedlang/compiler/types/IntType.java
+++ b/src/main/java/org/shedlang/compiler/types/IntType.java
@@ -1,5 +1,8 @@
 package org.shedlang.compiler.types;
 
+/**
+ * The {@code Int} type, representing arbitrary precision integers.
+ */
 public final class IntType implements Type {
     private IntType() {
     }
diff --git a/src/main/java/org/shedlang/compiler/types/StringType.java b/src/main/java/org/shedlang/compiler/types/StringType.java
index eb2374a3..3a20c9bb 100644
--- a/src/main/java/org/shedlang/compiler/types/StringType.java
+++ b/src/main/java/org/shedlang/compiler/types/StringType.java
@@ -1,5 +1,8 @@
 package org.shedlang.compiler.types;
 
+/**
+ * The {@code String} type. Strings are sequences of Unicode code points.
+ */
 public final class StringType implements Type {
     static final StringType INSTANCE = new StringType();
 
diff --git a/src/main/java/org/shedlang/compiler/types/UnitType.java b/src/main/java/org/shedlang/compiler/types/UnitType.java
index acc7aad0..db36f226 100644
--- a/src/main/java/org/shedlang/compiler/types/UnitType.java
+++ b/src/main/java/org/shedlang/compiler/types/UnitType.java
@@ -1,5 +1,9 @@
 package org.shedlang.compiler.types;
 
+/**
+ * The {@code Unit} type. Allows only one value, and therefore holds no
+ * information.
+ */
 public final class UnitType implements Type {
     static final UnitType INSTANCE = new UnitType();