Add builder for StructTypeInfo

2 files changed, 29 insertions, 6 deletions

diff --git a/src/main/java/org/shedlang/compiler/types/FieldsInfo.java b/src/main/java/org/shedlang/compiler/types/FieldsInfo.java
index 867e09ac..afe76757 100644
--- a/src/main/java/org/shedlang/compiler/types/FieldsInfo.java
+++ b/src/main/java/org/shedlang/compiler/types/FieldsInfo.java
@@ -1,5 +1,6 @@
 package org.shedlang.compiler.types;
 
+import org.shedlang.compiler.util.P;
 import org.shedlang.compiler.util.POrderedMap;
 
 import java.util.Map;
@@ -29,4 +30,18 @@ public record FieldsInfo<T extends Type>(POrderedMap<String, T> fields) {
     public Stream<Map.Entry<String, T>> stream() {
         return fields.entryStream();
     }
+
+    public static <T extends Type> Builder<T> builder() {
+        return new Builder<T>(P.orderedMap());
+    }
+
+    public record Builder<T extends Type>(POrderedMap<String, T> fields) {
+        public FieldsInfo<T> build() {
+            return new FieldsInfo<>(fields);
+        }
+
+        public Builder<T> addField(String name, T type) {
+            return new Builder<>(fields.plus(name, type));
+        }
+    }
 }
diff --git a/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java b/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java
index 15338cd6..1970b72e 100644
--- a/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java
+++ b/src/main/java/org/shedlang/compiler/types/StructTypeInfo.java
@@ -1,14 +1,8 @@
 package org.shedlang.compiler.types;
 
-import org.shedlang.compiler.util.POrderedMap;
-
 import java.util.Optional;
 
 public record StructTypeInfo(FieldsInfo<Type> fields) {
-    public static StructTypeInfo fromFields(POrderedMap<String, Type> fields) {
-        return new StructTypeInfo(new FieldsInfo<>(fields));
-    }
-
     public int fieldCount() {
         return fields().fieldCount();
     }
@@ -20,4 +14,18 @@ public record StructTypeInfo(FieldsInfo<Type> fields) {
     public int fieldIndex(String fieldName) {
         return fields.fieldIndex(fieldName);
     }
+
+    public static Builder builder() {
+        return new Builder(FieldsInfo.builder());
+    }
+
+    public record Builder(FieldsInfo.Builder<Type> fields) {
+        public StructTypeInfo build() {
+            return new StructTypeInfo(fields.build());
+        }
+
+        public Builder addField(String name, Type type) {
+            return new Builder(this.fields.addField(name, type));
+        }
+    }
 }