add some Javadoc, and rename a class

hibernate-core/src/main/java/org/hibernate/dialect/AbstractHANADialect.java

@@ -308,7 +308,7 @@ public abstract class AbstractHANADialect extends Dialect {
 		functionFactory.secondsBetween();
 		functionFactory.format_toVarchar();
 		functionFactory.currentUtcdatetimetimestamp();
-		functionFactory.everyAny_sumCaseCase();
+		functionFactory.everyAny_minMaxCase();
 		functionFactory.bitLength_pattern( "length(to_binary(?1))*8" );
 
 		functionFactory.listagg_stringAgg( "varchar" );

hibernate-core/src/main/java/org/hibernate/dialect/Dialect.java

@@ -885,7 +885,8 @@ public abstract class Dialect implements ConversionContext {
 		queryEngine.getSqmFunctionRegistry().register( "extract",
 				new ExtractFunction( this ) );
 
-		//comparison functions supported on every known database
+		//comparison functions supported on most databases, emulated on others
+		//using a case expression
 
 		functionFactory.leastGreatest();
 

hibernate-core/src/main/java/org/hibernate/dialect/OracleDialect.java

@@ -163,7 +163,7 @@ public class OracleDialect extends Dialect {
 		functionFactory.characterLength_length( SqlAstNodeRenderingMode.DEFAULT );
 		functionFactory.addMonths();
 		functionFactory.monthsBetween();
-		functionFactory.everyAny_sumCaseCase();
+		functionFactory.everyAny_minMaxCase();
 
 		functionFactory.median();
 		functionFactory.stddev();

hibernate-core/src/main/java/org/hibernate/dialect/SQLServerDialect.java

@@ -218,7 +218,7 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
 		functionFactory.avg_castingNonDoubleArguments( this, SqlAstNodeRenderingMode.DEFAULT );
 
 		functionFactory.truncate_round();
-		functionFactory.everyAny_sumIif();
+		functionFactory.everyAny_minMaxIif();
 		functionFactory.bitLength_pattern( "datalength(?1) * 8" );
 
 		if ( getVersion().isSameOrAfter( 10 ) ) {

hibernate-core/src/main/java/org/hibernate/dialect/SybaseDialect.java

@@ -220,7 +220,7 @@ public class SybaseDialect extends AbstractTransactSQLDialect {
 		functionFactory.locate_charindex();
 
 		functionFactory.replace_strReplace();
-		functionFactory.everyAny_sumCaseCase();
+		functionFactory.everyAny_minMaxCase();
 		functionFactory.bitLength_pattern( "datalength(?1) * 8" );
 
 		queryEngine.getSqmFunctionRegistry().register( "timestampadd",

hibernate-core/src/main/java/org/hibernate/dialect/function/CaseLeastGreatestEmulation.java

@@ -19,6 +19,8 @@ import org.hibernate.sql.ast.tree.SqlAstNode;
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.COMPARABLE;
 
 /**
+ * Some databases don't have a function like {@code least()} or {@code greatest()},
+ * and on those platforms we emulate the function using {@code case}.
  *
  * @author Christian Beikov
  */

hibernate-core/src/main/java/org/hibernate/dialect/function/CastFunction.java

@@ -23,6 +23,10 @@ import org.hibernate.sql.ast.tree.expression.CastTarget;
 import org.hibernate.sql.ast.tree.expression.Expression;
 
 /**
+ * ANSI SQL-inspired {@code cast()} function, where the target types
+ * are enumerated by {@link CastType}, and portability is achieved
+ * by delegating to {@link Dialect#castPattern(CastType, CastType)}.
+ *
  * @author Gavin King
  */
 public class CastFunction extends AbstractSqmSelfRenderingFunctionDescriptor {

hibernate-core/src/main/java/org/hibernate/dialect/function/CastStrEmulation.java

@@ -24,6 +24,8 @@ import java.util.List;
 import static java.util.Arrays.asList;
 
 /**
+ * The HQL {@code str()} function is now considered a synonym for {@code cast(x as String)}.
+ *
  * @author Gavin King
  */
 public class CastStrEmulation

hibernate-core/src/main/java/org/hibernate/dialect/function/CommonFunctionFactory.java

@@ -812,7 +812,7 @@ public class CommonFunctionFactory {
 	 * These are aggregate functions taking one argument,
 	 * for SQL Server.
 	 */
-	public void everyAny_sumIif() {
+	public void everyAny_minMaxIif() {
 		functionRegistry.register( "every",
 				new SQLServerEveryAnyEmulation( typeConfiguration, true ) );
 		functionRegistry.register( "any",
@@ -824,11 +824,11 @@ public class CommonFunctionFactory {
 	 * These are aggregate functions taking one argument,
 	 * for Oracle and Sybase.
 	 */
-	public void everyAny_sumCaseCase() {
+	public void everyAny_minMaxCase() {
 		functionRegistry.register( "every",
-				new CaseWhenEveryAnyEmulation( typeConfiguration, true ) );
+				new MinMaxCaseEveryAnyEmulation( typeConfiguration, true ) );
 		functionRegistry.register( "any",
-				new CaseWhenEveryAnyEmulation( typeConfiguration, false ) );
+				new MinMaxCaseEveryAnyEmulation( typeConfiguration, false ) );
 	}
 
 	/**

hibernate-core/src/main/java/org/hibernate/dialect/function/CurrentFunction.java

@@ -17,6 +17,9 @@ import org.hibernate.type.BasicType;
 import java.util.List;
 
 /**
+ * A "function" with no parameters that returns the current date, time, or timestamp.
+ * For example, {@code current_date}.
+ *
  * @author Gavin King
  */
 public class CurrentFunction

hibernate-core/src/main/java/org/hibernate/dialect/function/EveryAnyEmulation.java

@@ -23,6 +23,13 @@ import org.hibernate.type.spi.TypeConfiguration;
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.BOOLEAN;
 
 /**
+ * Most databases don't have a function like {@code every()} or {@code any()}.
+ * On many platforms we emulate the function using {@code sum()} together with
+ * {@code case}.
+ *
+ * @see MinMaxCaseEveryAnyEmulation
+ * @see SQLServerEveryAnyEmulation
+ *
  * @author Jan Schatteman
  */
 public class EveryAnyEmulation extends AbstractSqmSelfRenderingFunctionDescriptor {

hibernate-core/src/main/java/org/hibernate/dialect/function/ExtractFunction.java

@@ -33,6 +33,10 @@ import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TEM
 import static org.hibernate.query.sqm.produce.function.StandardFunctionReturnTypeResolvers.useArgType;
 
 /**
+ * ANSI SQL-inspired {@code extract()} function, where the date/time fields
+ * are enumerated by {@link TemporalUnit}, and portability is achieved
+ * by delegating to {@link Dialect#extractPattern(TemporalUnit)}.
+ *
  * @author Gavin King
  */
 public class ExtractFunction

hibernate-core/src/main/java/org/hibernate/dialect/function/InsertSubstringOverlayEmulation.java

@@ -35,6 +35,9 @@ import static org.hibernate.query.sqm.produce.function.FunctionParameterType.INT
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.STRING;
 
 /**
+ * Emulates the ANSI SQL-standard {@code overlay()} function using {@code insert()}
+ * {@code substring()}, and {@code concat()}.
+ *
  * @author Gavin King
  */
 public class InsertSubstringOverlayEmulation

hibernate-core/src/main/java/org/hibernate/dialect/function/LocatePositionEmulation.java

@@ -22,6 +22,8 @@ import java.util.List;
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.STRING;
 
 /**
+ * Emulates the ANSI SQL-standard {@code position()} function using {@code locate()}.
+ *
  * @author Gavin King
  */
 public class LocatePositionEmulation extends AbstractSqmFunctionDescriptor {

hibernate-core/src/main/java/org/hibernate/dialect/function/LpadRpadPadEmulation.java

@@ -27,6 +27,12 @@ import static org.hibernate.query.sqm.produce.function.FunctionParameterType.STR
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TRIM_SPEC;
 
 /**
+ * HQL function inspired by the {@linkplain TrimFunction ANSI SQL trim function},
+ * with a funny syntax involving a {@link TrimSpec}. Emulated using {@code rpad()}
+ * and {@code lpad()} or by equivalent emulations of those functions.
+ * <p>
+ * For example, {@code pad(text with 5 leading ' ')}.
+ *
  * @author Gavin King
  */
 public class LpadRpadPadEmulation

hibernate-core/src/main/java/org/hibernate/dialect/function/MinMaxCaseEveryAnyEmulation.java

@@ -22,13 +22,19 @@ import org.hibernate.type.StandardBasicTypes;
 import org.hibernate.type.spi.TypeConfiguration;
 
 /**
+ * Most databases don't have a function like {@code every()} or {@code any()}.
+ * On some platforms we emulate the function using {@code min()} or {@code max()}
+ * together with {@code case}.
+ *
+ * @see EveryAnyEmulation
+ *
  * @author Jan Schatteman
  */
-public class CaseWhenEveryAnyEmulation extends AbstractSqmSelfRenderingFunctionDescriptor {
+public class MinMaxCaseEveryAnyEmulation extends AbstractSqmSelfRenderingFunctionDescriptor {
 
 	private final boolean every;
 
-	public CaseWhenEveryAnyEmulation(TypeConfiguration typeConfiguration, boolean every) {
+	public MinMaxCaseEveryAnyEmulation(TypeConfiguration typeConfiguration, boolean every) {
 		super(
 				every ? "every" : "any",
 				FunctionKind.AGGREGATE,

hibernate-core/src/main/java/org/hibernate/dialect/function/QuantifiedLeastGreatestEmulation.java

@@ -19,6 +19,7 @@ import org.hibernate.sql.ast.tree.SqlAstNode;
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.COMPARABLE;
 
 /**
+ * @see CaseLeastGreatestEmulation
  *
  * @author Christian Beikov
  */

hibernate-core/src/main/java/org/hibernate/dialect/function/SQLServerEveryAnyEmulation.java

@@ -23,6 +23,12 @@ import org.hibernate.type.spi.TypeConfiguration;
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.BOOLEAN;
 
 /**
+ * SQL Server doesn't have a function like {@code every()} or {@code any()}.
+ * We emulate the function using {@code min()} or {@code max()} together with
+ * {@code iif()}.
+ *
+ * @see EveryAnyEmulation
+ *
  * @author Jan Schatteman
  */
 public class SQLServerEveryAnyEmulation extends AbstractSqmSelfRenderingFunctionDescriptor {

hibernate-core/src/main/java/org/hibernate/dialect/function/TransactSQLStrFunction.java

@@ -22,8 +22,9 @@ import org.hibernate.type.StandardBasicTypes;
 import org.hibernate.type.spi.TypeConfiguration;
 
 /**
- * A special function that renders to the T-SQL "str" function if more than a single argument is given,
+ * A special function that renders a T-SQL {@code str()} function
- * otherwise renders a cast expression like {@link CastStrEmulation}.
+ * if more than a single argument is given, or otherwise renders
+ * a {@code cast()} expression just like {@link CastStrEmulation}.
  *
  * @author Christian Beikov
  */

hibernate-core/src/main/java/org/hibernate/dialect/function/TrimFunction.java

@@ -29,6 +29,12 @@ import static org.hibernate.query.sqm.produce.function.FunctionParameterType.TRI
 import static org.hibernate.query.sqm.produce.function.FunctionParameterType.STRING;
 
 /**
+ * ANSI SQL-standard {@code trim()} function, which has a funny syntax
+ * involving a {@link TrimSpec}, and portability is achieved using
+ * {@link Dialect#trimPattern(TrimSpec, char)}.
+ * <p>
+ * For example, {@code trim(leading ' ' from text)}.
+ *
  * @author Gavin King
  */
 public class TrimFunction extends AbstractSqmSelfRenderingFunctionDescriptor {