Aggressively statically type query providers.

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseAbstract.java

@@ -43,7 +43,7 @@ public abstract class DDatabaseAbstract<
   C extends DDatabaseConfigurationType,
   N extends DDatabaseConnectionType<T>,
   T extends DDatabaseTransactionType,
-  Q extends DDatabaseQueryProviderType<T>>
+  Q extends DDatabaseQueryProviderType<T, ?, ?, ?>>
   implements DDatabaseType<C, N, T, Q>
 {
   private final C configuration;
@@ -69,7 +69,7 @@ protected DDatabaseAbstract(
 
   private static <
     T extends DDatabaseTransactionType,
-    Q extends DDatabaseQueryProviderType<T>>
+    Q extends DDatabaseQueryProviderType<T, ?, ?, ?>>
   Map<Class<?>, Q> collectQueryProviders(
     final Collection<Q> inQueryProviders)
   {

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseConnectionAbstract.java

@@ -36,7 +36,7 @@
 public abstract class DDatabaseConnectionAbstract<
   C extends DDatabaseConfigurationType,
   T extends DDatabaseTransactionType,
-  Q extends DDatabaseQueryProviderType<T>>
+  Q extends DDatabaseQueryProviderType<T, ?, ?, ?>>
   implements DDatabaseConnectionType<T>
 {
   private final Connection connection;

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseFactoryType.java

@@ -35,7 +35,7 @@ public interface DDatabaseFactoryType<
   C extends DDatabaseConfigurationType,
   N extends DDatabaseConnectionType<T>,
   T extends DDatabaseTransactionType,
-  Q extends DDatabaseQueryProviderType<T>,
+  Q extends DDatabaseQueryProviderType<T, ?, ?, ?>,
   D extends DDatabaseType<C, N, T, Q>>
 {
   /**

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseQueryProviderAbstract.java

@@ -24,17 +24,24 @@
  * A convenient abstract query provider.
  *
  * @param <T> The precise type of database transactions
+ * @param <P> The type of query parameters
+ * @param <R> The type of query results
+ * @param <Q> The precise type of query
  */
 
-public abstract class DDatabaseQueryProviderAbstract<T extends DDatabaseTransactionType>
-  implements DDatabaseQueryProviderType<T>
+public abstract class DDatabaseQueryProviderAbstract<
+  T extends DDatabaseTransactionType,
+  P,
+  R,
+  Q extends DDatabaseQueryType<P, R>>
+  implements DDatabaseQueryProviderType<T, P, R, Q>
 {
-  private final Class<?> queryClass;
-  private final Function<T, DDatabaseQueryType<?, ?>> constructor;
+  private final Class<? extends Q> queryClass;
+  private final Function<T, DDatabaseQueryType<P, R>> constructor;
 
   protected DDatabaseQueryProviderAbstract(
-    final Class<?> inQueryClass,
-    final Function<T, DDatabaseQueryType<?, ?>> inConstructor)
+    final Class<? extends Q> inQueryClass,
+    final Function<T, DDatabaseQueryType<P, R>> inConstructor)
   {
     this.queryClass =
       Objects.requireNonNull(inQueryClass, "queryClass");
@@ -43,13 +50,13 @@ protected DDatabaseQueryProviderAbstract(
   }
 
   @Override
-  public final Class<?> queryClass()
+  public final Class<? extends Q> queryClass()
   {
     return this.queryClass;
   }
 
   @Override
-  public final DDatabaseQueryType<?, ?> create(
+  public final DDatabaseQueryType<P, R> create(
     final T transaction)
   {
     return this.constructor.apply(transaction);

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseQueryProviderType.java

@@ -21,15 +21,22 @@
  * The type of database query providers.
  *
  * @param <T> The type of database transactions
+ * @param <P> The type of query parameters
+ * @param <R> The type of query results
+ * @param <Q> The precise type of query
  */
 
-public interface DDatabaseQueryProviderType<T extends DDatabaseTransactionType>
+public interface DDatabaseQueryProviderType<
+  T extends DDatabaseTransactionType,
+  P,
+  R,
+  Q extends DDatabaseQueryType<P, R>>
 {
   /**
    * @return The class that will be used to fetch this query provider
    */
 
-  Class<?> queryClass();
+  Class<? extends Q> queryClass();
 
   /**
    * Create a query for the given transaction.
@@ -39,5 +46,5 @@ public interface DDatabaseQueryProviderType<T extends DDatabaseTransactionType>
    * @return A new query
    */
 
-  DDatabaseQueryType<?, ?> create(T transaction);
+  DDatabaseQueryType<P, R> create(T transaction);
 }

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseTransactionAbstract.java

@@ -44,7 +44,7 @@ public abstract class DDatabaseTransactionAbstract<
   C extends DDatabaseConfigurationType,
   N extends DDatabaseConnectionType<T>,
   T extends DDatabaseTransactionType,
-  Q extends DDatabaseQueryProviderType<T>>
+  Q extends DDatabaseQueryProviderType<T, ?, ?, ?>>
   implements DDatabaseTransactionType
 {
   private final DDatabaseTransactionCloseBehavior closeBehavior;

com.io7m.darco.api/src/main/java/com/io7m/darco/api/DDatabaseType.java

@@ -30,7 +30,7 @@ public interface DDatabaseType<
   C extends DDatabaseConfigurationType,
   N extends DDatabaseConnectionType<T>,
   T extends DDatabaseTransactionType,
-  Q extends DDatabaseQueryProviderType<T>>
+  Q extends DDatabaseQueryProviderType<T, ?, ?, ?>>
   extends AutoCloseable
 {
   /**

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabase.java

@@ -32,13 +32,13 @@ final class EPQDatabase
   EPQDatabaseConfiguration,
   EPQDatabaseConnectionType,
   EPQDatabaseTransactionType,
-  EPQDatabaseQueryProviderType>
+  EPQDatabaseQueryProviderType<?, ?, ?>>
   implements EPQDatabaseType
 {
   EPQDatabase(
     final EPQDatabaseConfiguration inConfiguration,
     final DataSource inDataSource,
-    final Collection<EPQDatabaseQueryProviderType> queryProviders,
+    final Collection<EPQDatabaseQueryProviderType<?, ?, ?>> queryProviders,
     final CloseableCollectionType<DDatabaseException> resources)
   {
     super(inConfiguration, inDataSource, queryProviders, resources);
@@ -48,7 +48,7 @@ final class EPQDatabase
   protected EPQDatabaseConnectionType createConnection(
     final Span span,
     final Connection connection,
-    final Map<Class<?>, EPQDatabaseQueryProviderType> queries)
+    final Map<Class<?>, EPQDatabaseQueryProviderType<?, ?, ?>> queries)
   {
     return new EPQDatabaseConnection(this, span, connection, queries);
   }

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseConnection.java

@@ -26,16 +26,16 @@
 
 final class EPQDatabaseConnection
   extends DDatabaseConnectionAbstract<
-    EPQDatabaseConfiguration,
-    EPQDatabaseTransactionType,
-    EPQDatabaseQueryProviderType>
+  EPQDatabaseConfiguration,
+  EPQDatabaseTransactionType,
+  EPQDatabaseQueryProviderType<?, ?, ?>>
   implements EPQDatabaseConnectionType
 {
   EPQDatabaseConnection(
     final EPQDatabaseType database,
     final Span span,
     final Connection connection,
-    final Map<Class<?>, EPQDatabaseQueryProviderType> queries)
+    final Map<Class<?>, EPQDatabaseQueryProviderType<?, ?, ?>> queries)
   {
     super(database.configuration(), span, connection, queries);
   }
@@ -44,7 +44,7 @@ final class EPQDatabaseConnection
   protected EPQDatabaseTransactionType createTransaction(
     final DDatabaseTransactionCloseBehavior closeBehavior,
     final Span transactionSpan,
-    final Map<Class<?>, EPQDatabaseQueryProviderType> queries)
+    final Map<Class<?>, EPQDatabaseQueryProviderType<?, ?, ?>> queries)
   {
     return new EPQDatabaseTransaction(
       closeBehavior,

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseFactory.java

@@ -37,11 +37,11 @@
 
 public final class EPQDatabaseFactory
   extends DPQDatabaseFactory<
-    EPQDatabaseConfiguration,
-    EPQDatabaseConnectionType,
-    EPQDatabaseTransactionType,
-    EPQDatabaseQueryProviderType,
-    EPQDatabaseType>
+  EPQDatabaseConfiguration,
+  EPQDatabaseConnectionType,
+  EPQDatabaseTransactionType,
+  EPQDatabaseQueryProviderType<?, ?, ?>,
+  EPQDatabaseType>
   implements EPQDatabaseFactoryType
 {
   private static final Logger LOG =
@@ -72,7 +72,7 @@ protected Logger logger()
   protected EPQDatabaseType onCreateDatabase(
     final EPQDatabaseConfiguration configuration,
     final DataSource source,
-    final List<EPQDatabaseQueryProviderType> queryProviders,
+    final List<EPQDatabaseQueryProviderType<?, ?, ?>> queryProviders,
     final CloseableCollectionType<DDatabaseException> resources)
   {
     return new EPQDatabase(
@@ -121,11 +121,12 @@ protected void onPostUpgrade(
   }
 
   @Override
-  protected List<EPQDatabaseQueryProviderType> onRequireDatabaseQueryProviders()
+  protected List<EPQDatabaseQueryProviderType<?, ?, ?>> onRequireDatabaseQueryProviders()
   {
     return ServiceLoader.load(EPQDatabaseQueryProviderType.class)
       .stream()
       .map(ServiceLoader.Provider::get)
+      .map(x -> (EPQDatabaseQueryProviderType<?, ?, ?>) x)
       .collect(Collectors.toList());
   }
 }

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseFactoryType.java

@@ -28,7 +28,7 @@ public interface EPQDatabaseFactoryType
   EPQDatabaseConfiguration,
   EPQDatabaseConnectionType,
   EPQDatabaseTransactionType,
-  EPQDatabaseQueryProviderType,
+  EPQDatabaseQueryProviderType<?, ?, ?>,
   EPQDatabaseType>
 {
 

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseQueryProvider.java

@@ -22,21 +22,23 @@
 
 import java.util.function.Function;
 
-final class EPQDatabaseQueryProvider
-  extends DDatabaseQueryProviderAbstract<EPQDatabaseTransactionType>
-  implements EPQDatabaseQueryProviderType
+final class EPQDatabaseQueryProvider<P, R, Q extends DDatabaseQueryType<P, R>>
+  extends DDatabaseQueryProviderAbstract<EPQDatabaseTransactionType, P, R, Q>
+  implements EPQDatabaseQueryProviderType<P, R, Q>
 {
   private EPQDatabaseQueryProvider(
-    final Class<?> inQueryClass,
-    final Function<EPQDatabaseTransactionType, DDatabaseQueryType<?, ?>> inConstructor)
+    final Class<? extends Q> inQueryClass,
+    final Function<EPQDatabaseTransactionType, DDatabaseQueryType<P, R>> inConstructor)
   {
     super(inQueryClass, inConstructor);
   }
 
-  static EPQDatabaseQueryProviderType provide(
-    final Class<?> inQueryClass,
-    final Function<EPQDatabaseTransactionType, DDatabaseQueryType<?, ?>> inConstructor)
+  static <P, R, Q extends DDatabaseQueryType<P, R>>
+  EPQDatabaseQueryProviderType<P, R, Q>
+  provide(
+    final Class<? extends Q> inQueryClass,
+    final Function<EPQDatabaseTransactionType, DDatabaseQueryType<P, R>> inConstructor)
   {
-    return new EPQDatabaseQueryProvider(inQueryClass, inConstructor);
+    return new EPQDatabaseQueryProvider<>(inQueryClass, inConstructor);
   }
 }

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseQueryProviderType.java

@@ -18,13 +18,18 @@
 package com.io7m.darco.examples.postgresql;
 
 import com.io7m.darco.api.DDatabaseQueryProviderType;
+import com.io7m.darco.api.DDatabaseQueryType;
 
 /**
  * The type of example PostgreSQL database query providers.
+ *
+ * @param <P> The type of query parameters
+ * @param <R> The type of query results
+ * @param <Q> The precise type of query
  */
 
-public interface EPQDatabaseQueryProviderType
-  extends DDatabaseQueryProviderType<EPQDatabaseTransactionType>
+public interface EPQDatabaseQueryProviderType<P, R, Q extends DDatabaseQueryType<P, R>>
+  extends DDatabaseQueryProviderType<EPQDatabaseTransactionType, P, R, Q>
 {
 
 }

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseTransaction.java

@@ -28,15 +28,15 @@ final class EPQDatabaseTransaction
   EPQDatabaseConfiguration,
   EPQDatabaseConnectionType,
   EPQDatabaseTransactionType,
-  EPQDatabaseQueryProviderType>
+  EPQDatabaseQueryProviderType<?, ?, ?>>
   implements EPQDatabaseTransactionType
 {
   EPQDatabaseTransaction(
     final DDatabaseTransactionCloseBehavior closeBehavior,
     final EPQDatabaseConfiguration inConfiguration,
     final EPQDatabaseConnectionType inConnection,
     final Span inTransactionScope,
-    final Map<Class<?>, EPQDatabaseQueryProviderType> queries)
+    final Map<Class<?>, EPQDatabaseQueryProviderType<?, ?, ?>> queries)
   {
     super(
       closeBehavior,

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQDatabaseType.java

@@ -28,7 +28,7 @@ public interface EPQDatabaseType
   EPQDatabaseConfiguration,
   EPQDatabaseConnectionType,
   EPQDatabaseTransactionType,
-  EPQDatabaseQueryProviderType>
+  EPQDatabaseQueryProviderType<?, ?, ?>>
 {
 
 }

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQWordGet.java

@@ -40,9 +40,14 @@ public final class EPQWordGet
    * @return The query provider
    */
 
-  public static EPQDatabaseQueryProviderType provider()
+  public static EPQDatabaseQueryProviderType<
+    DDatabaseUnit, Optional<String>, ESWordGetType>
+  provider()
   {
-    return EPQDatabaseQueryProvider.provide(ESWordGetType.class, EPQWordGet::new);
+    return EPQDatabaseQueryProvider.provide(
+      ESWordGetType.class,
+      EPQWordGet::new
+    );
   }
 
   @Override
@@ -53,7 +58,8 @@ protected Optional<String> onExecute(
   {
     final var c = transaction.connection();
 
-    try (var s = c.prepareStatement("SELECT * FROM words ORDER BY RANDOM() LIMIT 1")) {
+    try (var s = c.prepareStatement(
+      "SELECT * FROM words ORDER BY RANDOM() LIMIT 1")) {
       try (var r = s.executeQuery()) {
         if (r.next()) {
           return Optional.of(r.getString(1));

com.io7m.darco.examples/src/main/java/com/io7m/darco/examples/postgresql/EPQWordPut.java

@@ -39,9 +39,14 @@ public final class EPQWordPut
    * @return The query provider
    */
 
-  public static EPQDatabaseQueryProviderType provider()
+  public static EPQDatabaseQueryProviderType<
+    String, DDatabaseUnit, ESWordPutType>
+  provider()
   {
-    return EPQDatabaseQueryProvider.provide(ESWordPutType.class, EPQWordPut::new);
+    return EPQDatabaseQueryProvider.provide(
+      ESWordPutType.class,
+      EPQWordPut::new
+    );
   }
 
   @Override