Add Type.isProgressive

src/main/java/net/hydromatic/morel/compile/Pretty.java

@@ -323,10 +323,7 @@ private StringBuilder prettyType(StringBuilder buf, int indent, int[] lineEnd,
     case RECORD_TYPE:
     case PROGRESSIVE_RECORD_TYPE:
       final RecordType recordType = (RecordType) typeVal.type;
-      final boolean progressive =
-          type.op() == Op.PROGRESSIVE_RECORD_TYPE
-              || recordType.argNameTypes.containsKey(
-              ProgressiveRecordType.DUMMY);
+      final boolean progressive = typeVal.type.isProgressive();
       buf.append("{");
       start = buf.length();
       recordType.argNameTypes.forEach((name, elementType) -> {

src/main/java/net/hydromatic/morel/compile/Resolver.java

@@ -32,7 +32,6 @@
 import net.hydromatic.morel.type.FnType;
 import net.hydromatic.morel.type.ForallType;
 import net.hydromatic.morel.type.ListType;
-import net.hydromatic.morel.type.ProgressiveRecordType;
 import net.hydromatic.morel.type.RecordLikeType;
 import net.hydromatic.morel.type.RecordType;
 import net.hydromatic.morel.type.TupleType;
@@ -416,13 +415,9 @@ private Core.Apply toCore(Ast.Apply apply) {
           makeProgressive(coreArg), recordSelector.name);
       if (type.op() == Op.TY_VAR
               && coreFn.type.op() == Op.FUNCTION_TYPE
-          || type instanceof RecordType
-              && ((RecordLikeType) type).argNameTypes().containsKey(
-                  ProgressiveRecordType.DUMMY)
+          || type.isProgressive()
           || type instanceof ListType
-              && ((ListType) type).elementType instanceof RecordType
-              && ((RecordLikeType) ((ListType) type).elementType)
-                  .argNameTypes().containsKey(ProgressiveRecordType.DUMMY)) {
+              && ((ListType) type).elementType.isProgressive()) {
         // If we are dereferencing a field in a progressive type, the type
         // available now may be more precise than the deduced type.
         type = ((FnType) coreFn.type).resultType;
@@ -438,7 +433,7 @@ private Core.Apply toCore(Ast.Apply apply) {
    * type. */
   private RecordLikeType makeProgressive(Core.Exp coreArg) {
     final RecordLikeType recordLikeType = (RecordLikeType) coreArg.type;
-    if (recordLikeType.argNameTypes().containsKey(ProgressiveRecordType.DUMMY)) {
+    if (coreArg.type.isProgressive()) {
       Object o = valueOf(coreArg);
       if (o instanceof Codes.TypedValue) {
         final Codes.TypedValue typedValue = (Codes.TypedValue) o;
@@ -701,13 +696,13 @@ private static boolean subsumes(Type actualType, Type expectedType) {
       if (expectedType.op() != Op.RECORD_TYPE) {
         return false;
       }
+      if (actualType.isProgressive()) {
+        return true;
+      }
       final SortedMap<String, Type> actualMap =
           ((RecordType) actualType).argNameTypes();
       final SortedMap<String, Type> expectedMap =
           ((RecordType) expectedType).argNameTypes();
-      if (actualMap.containsKey(ProgressiveRecordType.DUMMY)) {
-        return true;
-      }
       final Iterator<Map.Entry<String, Type>> actualIterator =
           actualMap.entrySet().iterator();
       final Iterator<Map.Entry<String, Type>> expectedIterator =

src/main/java/net/hydromatic/morel/compile/TypeMap.java

@@ -19,7 +19,6 @@
 package net.hydromatic.morel.compile;
 
 import net.hydromatic.morel.ast.AstNode;
-import net.hydromatic.morel.type.ProgressiveRecordType;
 import net.hydromatic.morel.type.RecordType;
 import net.hydromatic.morel.type.Type;
 import net.hydromatic.morel.type.TypeSystem;
@@ -98,12 +97,8 @@ public boolean typeIsVariable(AstNode node) {
     final Unifier.Term term = nodeTypeTerms.get(node);
     if (term instanceof Unifier.Variable) {
       final Type type = termToType(term);
-      if (type instanceof TypeVar
-          || type instanceof RecordType
-          && ((RecordType) type).argNameTypes.containsKey(
-              ProgressiveRecordType.DUMMY)) {
-        return true;
-      }
+      return type instanceof TypeVar
+          || type.isProgressive();
     }
     return false;
   }

src/main/java/net/hydromatic/morel/compile/TypeResolver.java

@@ -32,8 +32,6 @@
 import net.hydromatic.morel.type.Keys;
 import net.hydromatic.morel.type.ListType;
 import net.hydromatic.morel.type.PrimitiveType;
-import net.hydromatic.morel.type.ProgressiveRecordType;
-import net.hydromatic.morel.type.RecordLikeType;
 import net.hydromatic.morel.type.RecordType;
 import net.hydromatic.morel.type.TupleType;
 import net.hydromatic.morel.type.Type;
@@ -186,7 +184,7 @@ private Resolved deduceType_(@Nullable Session session, Environment env,
       List<Ast.Apply> applies = new ArrayList<>();
       forEachUnresolvedField(node2, typeMap, apply -> {
         final Type type = typeMap.getType(apply.arg);
-        if (isProgressive(type)) {
+        if (type.isProgressive()) {
           applies.add(apply);
         }
       });
@@ -201,14 +199,6 @@ private Resolved deduceType_(@Nullable Session session, Environment env,
     }
   }
 
-  // TODO: centralize and simplify the following logic
-  private static boolean isProgressive(Type type) {
-    return type instanceof ProgressiveRecordType
-        || type instanceof RecordLikeType
-        && ((RecordLikeType) type).argNameTypes()
-        .containsKey(ProgressiveRecordType.DUMMY);
-  }
-
   private Codes.@Nullable TypedValue expandField(Environment env, Ast.Exp exp) {
     switch (exp.op) {
     case APPLY:

src/main/java/net/hydromatic/morel/type/RecordLikeType.java

@@ -31,16 +31,6 @@ public interface RecordLikeType extends Type {
   /** Returns the type of the {@code i}th field, or throws. */
   Type argType(int i);
 
-  /** Returns whether this type is progressive.
-   *
-   * <p>Progressive types are records, but can have additional fields each time
-   * you look.
-   *
-   * <p>The "file" value is an example. */
-  default boolean isProgressive() {
-    return false;
-  }
-
   /** Returns a {@link net.hydromatic.morel.eval.Codes.TypedValue} if this
    * type wraps a single dynamically typed value, otherwise null. */
   default Codes.@Nullable TypedValue asTypedValue() {

src/main/java/net/hydromatic/morel/type/RecordType.java

@@ -74,6 +74,10 @@ public Key key() {
         : (RecordType) typeSystem.recordType(argNameTypes2.build());
   }
 
+  @Override public boolean isProgressive() {
+    return argNameTypes.containsKey(ProgressiveRecordType.DUMMY);
+  }
+
   /** Ordering that compares integer values numerically,
    * string values lexicographically,
    * and integer values before string values.

src/main/java/net/hydromatic/morel/type/Type.java

@@ -66,6 +66,16 @@ default Type substitute(TypeSystem typeSystem, List<? extends Type> types) {
         });
   }
 
+  /** Returns whether this type is progressive.
+   *
+   * <p>Progressive types are records, but can have additional fields each time
+   * you look.
+   *
+   * <p>The "file" value is an example. */
+  default boolean isProgressive() {
+    return false;
+  }
+
   /** Structural identifier of a type. */
   abstract class Key {
     public final Op op;