Merge pull request #8 from h908714124/supplierless

allow mapping with Function and Collector directly, without wrapping …

Author: h908714124

annotations/.gitignore

@@ -5,3 +5,4 @@
 /dependency-reduced-pom.xml
 /.gradle
 /build
+/out

annotations/src/main/java/net/jbock/Parameter.java

@@ -4,7 +4,6 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
-import java.util.function.Supplier;
 
 /**
  * <h3>Marker for parameter methods</h3>
@@ -56,8 +55,8 @@
    * <h3>Optional custom mapper</h3>
    *
    * <p>
-   * The mapper is a {@link java.util.function.Supplier Supplier} that returns a
-   * {@link java.util.function.Function Function&lt;String, X&gt;}.
+   * The mapper is a either a {@link java.util.function.Function Function&lt;String, X&gt;}
+   * or a {@link java.util.function.Supplier Supplier} that returns such a function.
    * The return value {@code X} is called the <em>mapper type</em>.
    * The parameter method must return {@code X}, or {@code Optional<X>} if the
    * parameter is {@link #optional()}, or {@code List<X>} if the parameter is
@@ -69,58 +68,57 @@
    * </p>
    *
    * <pre>{@code
-   * class PositiveNumberMapper implements Supplier&lt;Function&lt;String, Integer&gt;&gt; {
-   *
-   *   public Function&lt;String, Integer&gt; get() {
-   *     return s -> {
-   *       Integer r = Integer.valueOf(s);
-   *       if (r <= 0) {
-   *         throw new IllegalArgumentException("Positive number expected");
-   *       }
-   *       return r;
+   * class PositiveNumberMapper implements Function<String, Integer> {
+   *
+   *   public Integer apply(String s) {
+   *     Integer r = Integer.valueOf(s);
+   *     if (r <= 0) {
+   *       throw new IllegalArgumentException("Positive number expected");
    *     }
+   *     return r;
    *   }
    * }
    * }</pre>
    *
-   * @return an optional mapper class
+   * @return a mapper class
    */
-  Class<? extends Supplier> mappedBy() default Supplier.class;
+  Class<?> mappedBy() default Object.class;
 
   /**
    * <h3>Optional custom collector</h3>
    *
    * <p>
-   * The supplier must return a {@link java.util.stream.Collector Collector&lt;M, ?, X&gt;}
-   * where {@code X} is the parameter type, and {@code M} is the <em>mapper type</em>.
+   * This is either a {@link java.util.stream.Collector Collector&lt;M, ?, X&gt;}
+   * where {@code X} is the parameter type and {@code M} is the <em>mapper type</em>,
+   * or a {@link java.util.function.Supplier Supplier} that returns such a collector.
    * </p>
    *
    * <p>
    * For example, the following collector creates a {@code Set}:
    * </p>
    *
    * <pre>{@code
-   * class ToSetCollector&lt;E&gt; implements Supplier&lt;Collector&lt;E, ?, Set&lt;E&gt;&gt;&gt; {
+   * class ToSetCollector<E>; implements Supplier<Collector<E, ?, Set<E>>> {
    *
-   *   public Collector&lt;E, ?, Set&lt;E&gt;&gt; get() {
+   *   public Collector<E, ?, Set<E>> get() {
    *     return Collectors.toSet();
    *   }
    * }
    * }</pre>
    *
-   * @return an optional collector class
+   * @return an collector class
    */
-  Class<? extends Supplier> collectedBy() default Supplier.class;
+  Class<?> collectedBy() default Object.class;
 
   /**
-   * <p>Declares this parameter repeatable.</p>
+   * <p>Declares this parameter as repeatable.</p>
    *
    * @return true if this parameter is repeatable
    */
   boolean repeatable() default false;
 
   /**
-   * <p>Declares this parameter optional.</p>
+   * <p>Declares this parameter as optional.</p>
    *
    * <p>
    * <em>Note:</em>
@@ -135,7 +133,7 @@
 
   /**
    * <p>Declares a parameter that doesn't take an argument.
-   * For example, the following shell command contains a flag:</p>
+   * For example, the following shell command contains the flag {@code -l}:</p>
    *
    * <pre>{@code
    * ls -l
@@ -159,3 +157,4 @@
    */
   String bundleKey() default "";
 }
+

annotations/src/main/java/net/jbock/PositionalParameter.java

@@ -53,28 +53,28 @@
    * Optional custom mapper.
    * See {@link Parameter#mappedBy()}.
    *
-   * @return an optional mapper class
+   * @return a mapper class
    */
-  Class<? extends Supplier> mappedBy() default Supplier.class;
+  Class<?> mappedBy() default Object.class;
 
   /**
    * Optional custom collector.
    * See {@link Parameter#collectedBy()}.
    *
-   * @return an optional collector class
+   * @return a collector class
    */
-  Class<? extends Supplier> collectedBy() default Supplier.class;
+  Class<?> collectedBy() default Object.class;
 
   /**
-   * Declares this parameter repeatable.
+   * Declares this parameter as repeatable.
    * See {@link Parameter#repeatable()}.
    *
    * @return true if this parameter is repeatable
    */
   boolean repeatable() default false;
 
   /**
-   * Declares this parameter optional.
+   * Declares this parameter as optional.
    * See {@link Parameter#optional()}.
    *
    * @return true if this parameter is optional
@@ -89,3 +89,4 @@
    */
   String bundleKey() default "";
 }
+

core/build.gradle

@@ -15,7 +15,7 @@ repositories {
 
 dependencies {
     implementation 'com.squareup:javapoet:1.11.1'
-    compile 'com.github.h908714124:jbock-annotations:2.2'
+    compile 'com.github.h908714124:jbock-annotations:2.3'
     testImplementation 'com.google.testing.compile:compile-testing:0.18'
     testImplementation 'org.mockito:mockito-core:3.0.0'
     testImplementation 'org.junit.jupiter:junit-jupiter:5.5.1'

core/src/main/java/net/jbock/coerce/CoercionProvider.java

@@ -1,6 +1,8 @@
 package net.jbock.coerce;
 
+import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.ParameterSpec;
+import com.squareup.javapoet.ParameterizedTypeName;
 import com.squareup.javapoet.TypeName;
 import net.jbock.coerce.hint.HintProvider;
 import net.jbock.coerce.mappers.CoercionFactory;
@@ -14,7 +16,9 @@
 import javax.lang.model.type.TypeMirror;
 import java.util.List;
 import java.util.Optional;
+import java.util.function.Function;
 
+import static net.jbock.compiler.Constants.STRING;
 import static net.jbock.compiler.Util.snakeToCamel;
 
 public class CoercionProvider {
@@ -44,7 +48,7 @@ private Coercion run() {
       if (basicInfo.isRepeatable()) {
         return handleRepeatable();
       } else {
-        return handle();
+        return handleNotRepeatable();
       }
     } catch (UnknownTypeException e) {
       Optional<String> hint = HintProvider.instance().findHint(basicInfo);
@@ -53,11 +57,11 @@ private Coercion run() {
     }
   }
 
-  private Coercion handle() throws UnknownTypeException {
+  private Coercion handleNotRepeatable() throws UnknownTypeException {
     if (basicInfo.mapperClass().isPresent()) {
-      return handleExplicitMapper(basicInfo.mapperClass().get());
+      return handleExplicitMapperNotRepeatable(basicInfo.mapperClass().get());
     } else {
-      return handleAutoMapper();
+      return handleAutoMapperNotRepeatable();
     }
   }
 
@@ -69,17 +73,24 @@ private Coercion handleRepeatable() throws UnknownTypeException {
     }
   }
 
-  private Coercion handleAutoMapper() throws UnknownTypeException {
+  private Coercion handleAutoMapperNotRepeatable() throws UnknownTypeException {
     CoercionFactory factory = findCoercion(basicInfo.optionalInfo().orElse(basicInfo.returnType()));
     return factory.getCoercion(basicInfo, Optional.empty());
   }
 
-  private Coercion handleExplicitMapper(TypeElement mapperClass) {
+  private Coercion handleExplicitMapperNotRepeatable(TypeElement mapperClass) {
     TypeMirror returnType = basicInfo.returnType();
-    ParameterSpec mapperParam = ParameterSpec.builder(TypeName.get(mapperClass.asType()), snakeToCamel(basicInfo.paramName()) + "Mapper").build();
     TypeMirror mapperReturnType = basicInfo.optionalInfo().orElse(returnType);
-    MapperClassValidator.checkReturnType(mapperClass, mapperReturnType, basicInfo);
-    return MapperCoercion.create(mapperReturnType, Optional.empty(), mapperParam, mapperClass.asType(), basicInfo);
+    ParameterSpec mapperParam = mapperParam(mapperReturnType);
+    MapperType mapperType = new MapperClassValidator(basicInfo, mapperReturnType).checkReturnType(mapperClass);
+    return MapperCoercion.create(mapperReturnType, Optional.empty(), mapperParam, mapperType, basicInfo);
+  }
+
+  private ParameterSpec mapperParam(TypeMirror mapperOutputType) {
+    ParameterizedTypeName mapperParamType = ParameterizedTypeName.get(
+        ClassName.get(Function.class), STRING,
+        TypeName.get(mapperOutputType));
+    return ParameterSpec.builder(mapperParamType, snakeToCamel(basicInfo.paramName()) + "Mapper").build();
   }
 
   private Coercion handleRepeatableAutoMapper() throws UnknownTypeException {
@@ -91,9 +102,9 @@ private Coercion handleRepeatableAutoMapper() throws UnknownTypeException {
   private Coercion handleRepeatableExplicitMapper(
       TypeElement mapperClass) {
     CollectorInfo collectorInfo = collectorInfo();
-    MapperClassValidator.checkReturnType(mapperClass, collectorInfo.inputType, basicInfo);
-    ParameterSpec mapperParam = ParameterSpec.builder(TypeName.get(mapperClass.asType()), snakeToCamel(basicInfo.paramName()) + "Mapper").build();
-    return MapperCoercion.create(collectorInfo.inputType, collectorInfo.collectorType(), mapperParam, mapperClass.asType(), basicInfo);
+    MapperType mapperType = new MapperClassValidator(basicInfo, collectorInfo.inputType).checkReturnType(mapperClass);
+    ParameterSpec mapperParam = mapperParam(collectorInfo.inputType);
+    return MapperCoercion.create(collectorInfo.inputType, collectorInfo.collectorType(), mapperParam, mapperType, basicInfo);
   }
 
   private CoercionFactory findCoercion(TypeMirror mirror) throws UnknownTypeException {
@@ -127,7 +138,7 @@ private boolean isEnumType(TypeMirror mirror) {
 
   private CollectorInfo collectorInfo() {
     if (basicInfo.collectorClass().isPresent()) {
-      return CollectorClassValidator.getCollectorInfo(basicInfo.collectorClass().get(), basicInfo);
+      return new CollectorClassValidator(basicInfo).getCollectorInfo(basicInfo.collectorClass().get());
     }
     if (!tool().isSameErasure(basicInfo.returnType(), List.class)) {
       throw basicInfo.asValidationException("Either define a custom collector, or return List.");

core/src/main/java/net/jbock/coerce/CollectorClassValidator.java

@@ -1,10 +1,13 @@
 package net.jbock.coerce;
 
+import net.jbock.compiler.TypeTool;
 import net.jbock.compiler.ValidationException;
 
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.type.TypeMirror;
+import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.function.Supplier;
 import java.util.stream.Collector;
 
@@ -13,44 +16,55 @@
 
 class CollectorClassValidator {
 
+  private final BasicInfo basicInfo;
+
+  CollectorClassValidator(BasicInfo basicInfo) {
+    this.basicInfo = basicInfo;
+  }
+
   // visible for testing
-  static CollectorInfo getCollectorInfo(
-      TypeElement collectorClass,
-      BasicInfo basicInfo) {
+  CollectorInfo getCollectorInfo(TypeElement collectorClass) {
     commonChecks(basicInfo, collectorClass, "collector");
-    TypeMirror collectorType = getCollectorType(collectorClass, basicInfo);
-    TypeMirror t = asDeclared(collectorType).getTypeArguments().get(0);
-    TypeMirror r = asDeclared(collectorType).getTypeArguments().get(2);
-    Map<String, TypeMirror> solution = basicInfo.tool().unify(basicInfo.returnType(), r)
-        .orElseThrow(() -> boom(basicInfo, String.format("The collector should return %s but returns %s", basicInfo.returnType(), r)));
-    TypeMirror collectorClassSolved = basicInfo.tool().substitute(collectorClass.asType(), solution);
-    if (collectorClassSolved == null) {
-      throw boom(basicInfo, "Invalid bounds");
+    CollectorType collectorType = getCollectorType(collectorClass);
+    TypeMirror t = asDeclared(collectorType.type()).getTypeArguments().get(0);
+    TypeMirror r = asDeclared(collectorType.type()).getTypeArguments().get(2);
+    Map<String, TypeMirror> solution = tool().unify(basicInfo.returnType(), r)
+        .orElseThrow(() -> boom(String.format("The collector should return %s but returns %s", basicInfo.returnType(), r)));
+    if (tool().substitute(collectorClass.asType(), solution) == null) {
+      throw boom("Invalid bounds");
     }
-    TypeMirror substitute = basicInfo.tool().substitute(t, solution);
-    if (substitute == null) {
-      throw boom(basicInfo, "Unexpected: can solve R but not Collector<T, ?, R>");
+    TypeMirror collectorInput = tool().substitute(t, solution);
+    if (collectorInput == null) {
+      throw boom("Unexpected: can solve R but not Collector<T, ?, R>");
     }
-    return CollectorInfo.create(substitute, collectorClassSolved);
+    return CollectorInfo.create(collectorInput, collectorType);
   }
 
-  private static TypeMirror getCollectorType(TypeElement collectorClass, BasicInfo basicInfo) {
-    Resolver resolver = Resolver.resolve(basicInfo.tool().asType(Supplier.class), collectorClass.asType(), basicInfo.tool());
-    TypeMirror typeMirror = resolver.resolveTypevars().orElseThrow(() -> boom(basicInfo, "not a Supplier"));
-    if (basicInfo.tool().isRawType(typeMirror)) {
-      throw boom(basicInfo, "the supplier must be parameterized");
-    }
-    TypeMirror collectorType = asDeclared(typeMirror).getTypeArguments().get(0);
-    if (!basicInfo.tool().isSameErasure(collectorType, Collector.class)) {
-      throw boom(basicInfo, "the supplier must supply a Collector");
+  private CollectorType getCollectorType(TypeElement collectorClass) {
+    Optional<TypeMirror> supplier = Resolver.typecheck(
+        Supplier.class,
+        collectorClass.asType(),
+        basicInfo.tool());
+    if (supplier.isPresent()) {
+      List<? extends TypeMirror> typeArgs = asDeclared(supplier.get()).getTypeArguments();
+      if (typeArgs.isEmpty()) {
+        throw boom("raw Supplier type");
+      }
+      return CollectorType.create(basicInfo, typeArgs.get(0), true, collectorClass);
     }
-    if (basicInfo.tool().isRawType(collectorType)) {
-      throw boom(basicInfo, "the collector type must be parameterized");
-    }
-    return collectorType;
+    TypeMirror collector = Resolver.typecheck(
+        Collector.class,
+        collectorClass.asType(),
+        basicInfo.tool()).orElseThrow(() ->
+        boom("not a Collector or Supplier<Collector>"));
+    return CollectorType.create(basicInfo, collector, false, collectorClass);
+  }
+
+  private TypeTool tool() {
+    return basicInfo.tool();
   }
 
-  private static ValidationException boom(BasicInfo basicInfo, String message) {
+  private ValidationException boom(String message) {
     return basicInfo.asValidationException(String.format("There is a problem with the collector class: %s.", message));
   }
 }

core/src/main/java/net/jbock/coerce/CollectorInfo.java

@@ -3,26 +3,26 @@
 import javax.lang.model.type.TypeMirror;
 import java.util.Optional;
 
-class CollectorInfo {
+public class CollectorInfo {
 
   final TypeMirror inputType;
 
-  private final Optional<TypeMirror> collectorType;
+  private final Optional<CollectorType> collectorType;
 
-  private CollectorInfo(TypeMirror inputType, Optional<TypeMirror> collectorType) {
+  private CollectorInfo(TypeMirror inputType, Optional<CollectorType> collectorType) {
     this.inputType = inputType;
     this.collectorType = collectorType;
   }
 
-  static CollectorInfo create(TypeMirror inputType, TypeMirror collectorType) {
+  static CollectorInfo create(TypeMirror inputType, CollectorType collectorType) {
     return new CollectorInfo(inputType, Optional.of(collectorType));
   }
 
   static CollectorInfo listCollector(TypeMirror inputType) {
     return new CollectorInfo(inputType, Optional.empty());
   }
 
-  Optional<TypeMirror> collectorType() {
+  Optional<CollectorType> collectorType() {
     return collectorType;
   }