public void testLambdaCallsBinaryOp() {
// A parameter for the lambda expression.
ParameterExpression paramExpr = Expressions.parameter(Integer.TYPE, "arg");
// This expression represents a lambda expression
// that adds 1 to the parameter value.
FunctionExpression lambdaExpr =
Expressions.lambda(
Expressions.add(paramExpr, Expressions.constant(2)), Arrays.asList(paramExpr));
// Print out the expression.
String s = Expressions.toString(lambdaExpr);
assertEquals(
"new net.hydromatic.linq4j.function.Function1() {\n"
+ " public int apply(Integer arg) {\n"
+ " return arg + 2;\n"
+ " }\n"
+ " public Object apply(Object arg) {\n"
+ " return apply(\n"
+ " (Integer) arg);\n"
+ " }\n"
+ "}\n",
s);
// Compile and run the lambda expression.
// The value of the parameter is 1.
int n = (Integer) lambdaExpr.compile().dynamicInvoke(1);
// This code example produces the following output:
//
// arg => (arg +2)
// 3
assertEquals(3, n);
}
/**
* Gets the expression for an input and counts it.
*
* @param index Input ordinal
* @return Expression to which an input should be translated
*/
private Expression getInput(int index) {
Slot slot = inputSlots.get(index);
if (list == null) {
slot.count++;
} else {
if (slot.count > 1 && slot.parameterExpression == null) {
slot.parameterExpression = Expressions.parameter(slot.expression.type, "current" + index);
list.add(Expressions.declare(Modifier.FINAL, slot.parameterExpression, slot.expression));
}
}
return slot.parameterExpression != null ? slot.parameterExpression : slot.expression;
}
public void testLambdaCallsTwoArgMethod() throws NoSuchMethodException {
// A parameter for the lambda expression.
ParameterExpression paramS = Expressions.parameter(String.class, "s");
ParameterExpression paramBegin = Expressions.parameter(Integer.TYPE, "begin");
ParameterExpression paramEnd = Expressions.parameter(Integer.TYPE, "end");
// This expression represents a lambda expression
// that adds 1 to the parameter value.
FunctionExpression lambdaExpr =
Expressions.lambda(
Expressions.call(
paramS,
String.class.getMethod("substring", Integer.TYPE, Integer.TYPE),
paramBegin,
paramEnd),
paramS,
paramBegin,
paramEnd);
// Compile and run the lambda expression.
String s = (String) lambdaExpr.compile().dynamicInvoke("hello world", 3, 7);
assertEquals("lo w", s);
}
@Override
protected PreparedExecution implement(
RelDataType rowType,
RelNode rootRel,
SqlKind sqlKind,
ClassDeclaration decl,
Argument[] args) {
RelDataType resultType = rootRel.getRowType();
boolean isDml = sqlKind.belongsTo(SqlKind.DML);
javaCompiler = createCompiler();
EnumerableRelImplementor relImplementor =
getRelImplementor(rootRel.getCluster().getRexBuilder());
BlockExpression expr = relImplementor.implementRoot((EnumerableRel) rootRel);
ParameterExpression root0 = Expressions.parameter(DataContext.class, "root0");
String s =
Expressions.toString(
Blocks.create(
Expressions.declare(
Modifier.FINAL, (ParameterExpression) schema.getExpression(), root0),
expr),
false);
final Executable executable;
try {
executable =
(Executable)
ExpressionEvaluator.createFastScriptEvaluator(
s, Executable.class, new String[] {root0.name});
} catch (Exception e) {
throw Helper.INSTANCE.wrap("Error while compiling generated Java code:\n" + s, e);
}
if (timingTracer != null) {
timingTracer.traceTime("end codegen");
}
if (timingTracer != null) {
timingTracer.traceTime("end compilation");
}
return new PreparedExecution(
null, rootRel, resultType, isDml, mapTableModOp(isDml, sqlKind), null) {
public Object execute() {
return executable.execute(schema);
}
};
}
public void testCompile() throws NoSuchMethodException {
// Creating a parameter for the expression tree.
ParameterExpression param = Expressions.parameter(String.class);
// Creating an expression for the method call and specifying its
// parameter.
MethodCallExpression methodCall =
Expressions.call(Integer.class, "valueOf", Collections.<Expression>singletonList(param));
// The following statement first creates an expression tree,
// then compiles it, and then runs it.
int x =
Expressions.<Function1<String, Integer>>lambda(
methodCall, new ParameterExpression[] {param})
.getFunction()
.apply("1234");
assertEquals(1234, x);
}
private Expression translate(RexNode expr) {
Slot slot = map.get(expr);
if (slot == null) {
Expression expression = translate0(expr);
assert expression != null;
final ParameterExpression parameter;
if (!inlineRexSet.contains(expr) && !(expr instanceof RexLocalRef)) {
parameter = Expressions.parameter(expression.getType(), "v" + map.size());
} else {
parameter = null;
}
slot = new Slot(parameter, expression);
if (parameter != null && list != null) {
list.add(Expressions.declare(Modifier.FINAL, slot.parameterExpression, slot.expression));
}
map.put(expr, slot);
}
slot.count++;
return slot.parameterExpression != null ? slot.parameterExpression : slot.expression;
}
public void testWrite() {
assertEquals(
"1 + 2.0F + 3L + Long.valueOf(4L)",
Expressions.toString(
Expressions.add(
Expressions.add(
Expressions.add(Expressions.constant(1), Expressions.constant(2F, Float.TYPE)),
Expressions.constant(3L, Long.TYPE)),
Expressions.constant(4L, Long.class))));
assertEquals(
"new java.math.BigDecimal(31415926L, 7)",
Expressions.toString(Expressions.constant(BigDecimal.valueOf(314159260, 8))));
// Parentheses needed, to override the left-associativity of +.
assertEquals(
"1 + (2 + 3)",
Expressions.toString(
Expressions.add(
Expressions.constant(1),
Expressions.add(Expressions.constant(2), Expressions.constant(3)))));
// No parentheses needed; higher precedence of * achieves the desired
// effect.
assertEquals(
"1 + 2 * 3",
Expressions.toString(
Expressions.add(
Expressions.constant(1),
Expressions.multiply(Expressions.constant(2), Expressions.constant(3)))));
assertEquals(
"1 * (2 + 3)",
Expressions.toString(
Expressions.multiply(
Expressions.constant(1),
Expressions.add(Expressions.constant(2), Expressions.constant(3)))));
// Parentheses needed, to overcome right-associativity of =.
assertEquals(
"(1 = 2) = 3",
Expressions.toString(
Expressions.assign(
Expressions.assign(Expressions.constant(1), Expressions.constant(2)),
Expressions.constant(3))));
// Ternary operator.
assertEquals(
"1 < 2 ? (3 < 4 ? 5 : 6) : 7 < 8 ? 9 : 10",
Expressions.toString(
Expressions.condition(
Expressions.lessThan(Expressions.constant(1), Expressions.constant(2)),
Expressions.condition(
Expressions.lessThan(Expressions.constant(3), Expressions.constant(4)),
Expressions.constant(5),
Expressions.constant(6)),
Expressions.condition(
Expressions.lessThan(Expressions.constant(7), Expressions.constant(8)),
Expressions.constant(9),
Expressions.constant(10)))));
assertEquals(
"0 + (double) (2 + 3)",
Expressions.toString(
Expressions.add(
Expressions.constant(0),
Expressions.convert_(
Expressions.add(Expressions.constant(2), Expressions.constant(3)),
Double.TYPE))));
assertEquals(
"a.empno",
Expressions.toString(
Expressions.field(Expressions.parameter(Linq4jTest.Employee.class, "a"), "empno")));
assertEquals(
"java.util.Collections.EMPTY_LIST",
Expressions.toString(Expressions.field(null, Collections.class, "EMPTY_LIST")));
final ParameterExpression paramX = Expressions.parameter(String.class, "x");
assertEquals(
"new net.hydromatic.linq4j.function.Function1() {\n"
+ " public int apply(String x) {\n"
+ " return x.length();\n"
+ " }\n"
+ " public Object apply(Object x) {\n"
+ " return apply(\n"
+ " (String) x);\n"
+ " }\n"
+ "}\n",
Expressions.toString(
Expressions.lambda(
Function1.class,
Expressions.call(paramX, "length", Collections.<Expression>emptyList()),
Arrays.asList(paramX))));
assertEquals(
"new String[] {\n" + " \"foo\",\n" + " null,\n" + " \"bar\\\"baz\"}",
Expressions.toString(
Expressions.newArrayInit(
String.class,
Arrays.<Expression>asList(
Expressions.constant("foo"),
Expressions.constant(null),
Expressions.constant("bar\"baz")))));
assertEquals(
"(int) ((String) (Object) \"foo\").length()",
Expressions.toString(
Expressions.convert_(
Expressions.call(
Expressions.convert_(
Expressions.convert_(Expressions.constant("foo"), Object.class),
String.class),
"length",
Collections.<Expression>emptyList()),
Integer.TYPE)));
// resolving a static method
assertEquals(
"Integer.valueOf(\"0123\")",
Expressions.toString(
Expressions.call(
Integer.class,
"valueOf",
Collections.<Expression>singletonList(Expressions.constant("0123")))));
// precedence of not and instanceof
assertEquals(
"!(o instanceof String)",
Expressions.toString(
Expressions.not(
Expressions.typeIs(Expressions.parameter(Object.class, "o"), String.class))));
// not not
assertEquals(
"!!(o instanceof String)",
Expressions.toString(
Expressions.not(
Expressions.not(
Expressions.typeIs(Expressions.parameter(Object.class, "o"), String.class)))));
}
public void testWriteAnonymousClass() {
// final List<String> baz = Arrays.asList("foo", "bar");
// new AbstractList<String>() {
// public int size() {
// return baz.size();
// }
// public String get(int index) {
// return ((String) baz.get(index)).toUpperCase();
// }
// }
final ParameterExpression bazParameter =
Expressions.parameter(Types.of(List.class, String.class), "baz");
final ParameterExpression indexParameter = Expressions.parameter(Integer.TYPE, "index");
BlockExpression e =
Expressions.block(
Expressions.declare(
Modifier.FINAL,
bazParameter,
Expressions.call(
Arrays.class,
"asList",
Arrays.<Expression>asList(
Expressions.constant("foo"), Expressions.constant("bar")))),
Expressions.statement(
Expressions.new_(
Types.of(AbstractList.class, String.class),
Collections.<Expression>emptyList(),
Arrays.<MemberDeclaration>asList(
Expressions.fieldDecl(
Modifier.PUBLIC | Modifier.FINAL,
Expressions.parameter(String.class, "qux"),
Expressions.constant("xyzzy")),
Expressions.methodDecl(
Modifier.PUBLIC,
Integer.TYPE,
"size",
Collections.<ParameterExpression>emptyList(),
Blocks.toFunctionBlock(
Expressions.call(
bazParameter, "size", Collections.<Expression>emptyList()))),
Expressions.methodDecl(
Modifier.PUBLIC,
String.class,
"get",
Arrays.asList(indexParameter),
Blocks.toFunctionBlock(
Expressions.call(
Expressions.convert_(
Expressions.call(
bazParameter,
"get",
Arrays.<Expression>asList(indexParameter)),
String.class),
"toUpperCase",
Collections.<Expression>emptyList())))))));
assertEquals(
"{\n"
+ " final java.util.List<String> baz = java.util.Arrays.asList(\"foo\", \"bar\");\n"
+ " new java.util.AbstractList<String>(){\n"
+ " public final String qux = \"xyzzy\";\n"
+ " public int size() {\n"
+ " return baz.size();\n"
+ " }\n"
+ "\n"
+ " public String get(int index) {\n"
+ " return ((String) baz.get(index)).toUpperCase();\n"
+ " }\n"
+ "\n"
+ " };\n"
+ "}\n",
Expressions.toString(e));
}