Examples with ConditionalStatement org.apache.calcite.linq4j.tree.ConditionalStatement used on opensource projects

Example 1 with ConditionalStatement

use of org.apache.calcite.linq4j.tree.ConditionalStatement in project calcite by apache.

the class EnumerableRelImplementor method classDecl.

private ClassDeclaration classDecl(JavaTypeFactoryImpl.SyntheticRecordType type) {
    ClassDeclaration classDeclaration = Expressions.classDecl(Modifier.PUBLIC | Modifier.STATIC, type.getName(), null, ImmutableList.<Type>of(Serializable.class), new ArrayList<MemberDeclaration>());
    // ...
    for (Types.RecordField field : type.getRecordFields()) {
        classDeclaration.memberDeclarations.add(Expressions.fieldDecl(field.getModifiers(), Expressions.parameter(field.getType(), field.getName()), null));
    }
    // Constructor:
    // Foo(T0 f0, ...) { this.f0 = f0; ... }
    final BlockBuilder blockBuilder = new BlockBuilder();
    final List<ParameterExpression> parameters = new ArrayList<>();
    final ParameterExpression thisParameter = Expressions.parameter(type, "this");
    // Here a constructor without parameter is used because the generated
    // code could cause error if number of fields is too large.
    classDeclaration.memberDeclarations.add(Expressions.constructorDecl(Modifier.PUBLIC, type, parameters, blockBuilder.toBlock()));
    // equals method():
    // public boolean equals(Object o) {
    // if (this == o) return true;
    // if (!(o instanceof MyClass)) return false;
    // final MyClass that = (MyClass) o;
    // return this.f0 == that.f0
    // && equal(this.f1, that.f1)
    // ...
    // }
    final BlockBuilder blockBuilder2 = new BlockBuilder();
    final ParameterExpression thatParameter = Expressions.parameter(type, "that");
    final ParameterExpression oParameter = Expressions.parameter(Object.class, "o");
    blockBuilder2.add(Expressions.ifThen(Expressions.equal(thisParameter, oParameter), Expressions.return_(null, Expressions.constant(true))));
    blockBuilder2.add(Expressions.ifThen(Expressions.not(Expressions.typeIs(oParameter, type)), Expressions.return_(null, Expressions.constant(false))));
    blockBuilder2.add(Expressions.declare(Modifier.FINAL, thatParameter, Expressions.convert_(oParameter, type)));
    final List<Expression> conditions = new ArrayList<>();
    for (Types.RecordField field : type.getRecordFields()) {
        conditions.add(Primitive.is(field.getType()) ? Expressions.equal(Expressions.field(thisParameter, field.getName()), Expressions.field(thatParameter, field.getName())) : Expressions.call(BuiltInMethod.OBJECTS_EQUAL.method, Expressions.field(thisParameter, field.getName()), Expressions.field(thatParameter, field.getName())));
    }
    blockBuilder2.add(Expressions.return_(null, Expressions.foldAnd(conditions)));
    classDeclaration.memberDeclarations.add(Expressions.methodDecl(Modifier.PUBLIC, boolean.class, "equals", Collections.singletonList(oParameter), blockBuilder2.toBlock()));
    // hashCode method:
    // public int hashCode() {
    // int h = 0;
    // h = hash(h, f0);
    // ...
    // return h;
    // }
    final BlockBuilder blockBuilder3 = new BlockBuilder();
    final ParameterExpression hParameter = Expressions.parameter(int.class, "h");
    final ConstantExpression constantZero = Expressions.constant(0);
    blockBuilder3.add(Expressions.declare(0, hParameter, constantZero));
    for (Types.RecordField field : type.getRecordFields()) {
        final Method method = BuiltInMethod.HASH.method;
        blockBuilder3.add(Expressions.statement(Expressions.assign(hParameter, Expressions.call(method.getDeclaringClass(), method.getName(), ImmutableList.of(hParameter, Expressions.field(thisParameter, field))))));
    }
    blockBuilder3.add(Expressions.return_(null, hParameter));
    classDeclaration.memberDeclarations.add(Expressions.methodDecl(Modifier.PUBLIC, int.class, "hashCode", Collections.<ParameterExpression>emptyList(), blockBuilder3.toBlock()));
    // compareTo method:
    // public int compareTo(MyClass that) {
    // int c;
    // c = compare(this.f0, that.f0);
    // if (c != 0) return c;
    // ...
    // return 0;
    // }
    final BlockBuilder blockBuilder4 = new BlockBuilder();
    final ParameterExpression cParameter = Expressions.parameter(int.class, "c");
    final int mod = type.getRecordFields().size() == 1 ? Modifier.FINAL : 0;
    blockBuilder4.add(Expressions.declare(mod, cParameter, null));
    final ConditionalStatement conditionalStatement = Expressions.ifThen(Expressions.notEqual(cParameter, constantZero), Expressions.return_(null, cParameter));
    for (Types.RecordField field : type.getRecordFields()) {
        MethodCallExpression compareCall;
        try {
            final Method method = (field.nullable() ? BuiltInMethod.COMPARE_NULLS_LAST : BuiltInMethod.COMPARE).method;
            compareCall = Expressions.call(method.getDeclaringClass(), method.getName(), Expressions.field(thisParameter, field), Expressions.field(thatParameter, field));
        } catch (RuntimeException e) {
            if (e.getCause() instanceof NoSuchMethodException) {
                // In those cases it is fine if we skip the problematic fields.
                continue;
            }
            throw e;
        }
        blockBuilder4.add(Expressions.statement(Expressions.assign(cParameter, compareCall)));
        blockBuilder4.add(conditionalStatement);
    }
    blockBuilder4.add(Expressions.return_(null, constantZero));
    classDeclaration.memberDeclarations.add(Expressions.methodDecl(Modifier.PUBLIC, int.class, "compareTo", Collections.singletonList(thatParameter), blockBuilder4.toBlock()));
    // toString method:
    // public String toString() {
    // return "{f0=" + f0
    // + ", f1=" + f1
    // ...
    // + "}";
    // }
    final BlockBuilder blockBuilder5 = new BlockBuilder();
    Expression expression5 = null;
    for (Types.RecordField field : type.getRecordFields()) {
        if (expression5 == null) {
            expression5 = Expressions.constant("{" + field.getName() + "=");
        } else {
            expression5 = Expressions.add(expression5, Expressions.constant(", " + field.getName() + "="));
        }
        expression5 = Expressions.add(expression5, Expressions.field(thisParameter, field.getName()));
    }
    expression5 = expression5 == null ? Expressions.constant("{}") : Expressions.add(expression5, Expressions.constant("}"));
    blockBuilder5.add(Expressions.return_(null, expression5));
    classDeclaration.memberDeclarations.add(Expressions.methodDecl(Modifier.PUBLIC, String.class, "toString", Collections.<ParameterExpression>emptyList(), blockBuilder5.toBlock()));
    return classDeclaration;
}