Interpreter.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//CSOFF: FileLength
package org.apache.commons.jexl3.internal;
import java.util.Iterator;
import java.util.concurrent.Callable;
import java.util.function.Consumer;
import org.apache.commons.jexl3.JexlArithmetic;
import org.apache.commons.jexl3.JexlContext;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.JexlException;
import org.apache.commons.jexl3.JexlInfo;
import org.apache.commons.jexl3.JexlOperator;
import org.apache.commons.jexl3.JexlOptions;
import org.apache.commons.jexl3.JexlScript;
import org.apache.commons.jexl3.JxltEngine;
import org.apache.commons.jexl3.introspection.JexlMethod;
import org.apache.commons.jexl3.introspection.JexlPropertyGet;
import org.apache.commons.jexl3.parser.*;
/**
* An interpreter of JEXL syntax.
*
* @since 2.0
*/
public class Interpreter extends InterpreterBase {
/** Frame height. */
protected int fp = 0;
/** Symbol values. */
protected final Frame frame;
/** Block micro-frames. */
protected LexicalFrame block = null;
/**
* The thread local interpreter.
*/
protected static final java.lang.ThreadLocal<Interpreter> INTER =
new java.lang.ThreadLocal<>();
/**
* Creates an interpreter.
* @param engine the engine creating this interpreter
* @param aContext the evaluation context, global variables, methods and functions
* @param opts the evaluation options, flags modifying evaluation behavior
* @param eFrame the evaluation frame, arguments and local variables
*/
protected Interpreter(final Engine engine, final JexlOptions opts, final JexlContext aContext, final Frame eFrame) {
super(engine, opts, aContext);
this.frame = eFrame;
}
/**
* Copy constructor.
* @param ii the interpreter to copy
* @param jexla the arithmetic instance to use (or null)
*/
protected Interpreter(final Interpreter ii, final JexlArithmetic jexla) {
super(ii, jexla);
frame = ii.frame;
block = ii.block != null? new LexicalFrame(ii.block) : null;
}
/**
* Swaps the current thread local interpreter.
* @param inter the interpreter or null
* @return the previous thread local interpreter
*/
protected Interpreter putThreadInterpreter(final Interpreter inter) {
final Interpreter pinter = INTER.get();
INTER.set(inter);
return pinter;
}
/**
* Interpret the given script/expression.
* <p>
* If the underlying JEXL engine is silent, errors will be logged through
* its logger as warning.
* @param node the script or expression to interpret.
* @return the result of the interpretation.
* @throws JexlException if any error occurs during interpretation.
*/
public Object interpret(final JexlNode node) {
JexlContext.ThreadLocal tcontext = null;
JexlEngine tjexl = null;
Interpreter tinter = null;
try {
tinter = putThreadInterpreter(this);
if (tinter != null) {
fp = tinter.fp + 1;
}
if (context instanceof JexlContext.ThreadLocal) {
tcontext = jexl.putThreadLocal((JexlContext.ThreadLocal) context);
}
tjexl = jexl.putThreadEngine(jexl);
if (fp > jexl.stackOverflow) {
throw new JexlException.StackOverflow(node.jexlInfo(), "jexl (" + jexl.stackOverflow + ")", null);
}
cancelCheck(node);
return arithmetic.controlReturn(node.jjtAccept(this, null));
} catch(final StackOverflowError xstack) {
final JexlException xjexl = new JexlException.StackOverflow(node.jexlInfo(), "jvm", xstack);
if (!isSilent()) {
throw xjexl.clean();
}
if (logger.isWarnEnabled()) {
logger.warn(xjexl.getMessage(), xjexl.getCause());
}
} catch (final JexlException.Return xreturn) {
return xreturn.getValue();
} catch (final JexlException.Cancel xcancel) {
// cancelled |= Thread.interrupted();
cancelled.weakCompareAndSet(false, Thread.interrupted());
if (isCancellable()) {
throw xcancel.clean();
}
} catch (final JexlException xjexl) {
if (!isSilent()) {
throw xjexl.clean();
}
if (logger.isWarnEnabled()) {
logger.warn(xjexl.getMessage(), xjexl.getCause());
}
} finally {
// clean functors at top level
if (fp == 0) {
synchronized (this) {
if (functors != null) {
for (final Object functor : functors.values()) {
closeIfSupported(functor);
}
functors.clear();
functors = null;
}
}
}
jexl.putThreadEngine(tjexl);
if (context instanceof JexlContext.ThreadLocal) {
jexl.putThreadLocal(tcontext);
}
if (tinter != null) {
fp = tinter.fp - 1;
}
putThreadInterpreter(tinter);
}
return null;
}
/**
* Gets an attribute of an object.
*
* @param object to retrieve value from
* @param attribute the attribute of the object, e.g. an index (1, 0, 2) or key for a map
* @return the attribute value
*/
public Object getAttribute(final Object object, final Object attribute) {
return getAttribute(object, attribute, null);
}
/**
* Sets an attribute of an object.
*
* @param object to set the value to
* @param attribute the attribute of the object, e.g. an index (1, 0, 2) or key for a map
* @param value the value to assign to the object's attribute
*/
public void setAttribute(final Object object, final Object attribute, final Object value) {
setAttribute(object, attribute, value, null);
}
@Override
protected Object visit(final ASTAddNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.ADD, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.add(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "+ error", xrt);
}
}
@Override
protected Object visit(final ASTSubNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.SUBTRACT, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.subtract(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "- error", xrt);
}
}
@Override
protected Object visit(final ASTMulNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.MULTIPLY, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.multiply(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "* error", xrt);
}
}
@Override
protected Object visit(final ASTDivNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.DIVIDE, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.divide(left, right);
} catch (final ArithmeticException xrt) {
if (!arithmetic.isStrict()) {
return 0.0d;
}
throw new JexlException(findNullOperand(node, left, right), "/ error", xrt);
}
}
@Override
protected Object visit(final ASTModNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.MOD, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.mod(left, right);
} catch (final ArithmeticException xrt) {
if (!arithmetic.isStrict()) {
return 0.0d;
}
throw new JexlException(findNullOperand(node, left, right), "% error", xrt);
}
}
@Override
protected Object visit(final ASTBitwiseAndNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.AND, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.and(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "& error", xrt);
}
}
@Override
protected Object visit(final ASTBitwiseOrNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.OR, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.or(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "| error", xrt);
}
}
@Override
protected Object visit(final ASTBitwiseXorNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.XOR, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.xor(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "^ error", xrt);
}
}
@Override
protected Object visit(final ASTShiftLeftNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.SHIFTLEFT, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.shiftLeft(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "<< error", xrt);
}
}
@Override
protected Object visit(final ASTShiftRightNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.SHIFTRIGHT, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.shiftRight(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), ">> error", xrt);
}
}
@Override
protected Object visit(final ASTShiftRightUnsignedNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.SHIFTRIGHTU, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.shiftRightUnsigned(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), ">> error", xrt);
}
}
@Override
protected Object visit(final ASTEQNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.EQ, left, right);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.equals(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "== error", xrt);
}
}
@Override
protected Object visit(final ASTNENode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.EQ, left, right);
return result != JexlEngine.TRY_FAILED
? !arithmetic.toBoolean(result)
: !arithmetic.equals(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "!= error", xrt);
}
}
@Override
protected Object visit(final ASTGENode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.GTE, left, right);
return result != JexlEngine.TRY_FAILED
? result
: arithmetic.greaterThanOrEqual(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), ">= error", xrt);
}
}
@Override
protected Object visit(final ASTGTNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.GT, left, right);
return result != JexlEngine.TRY_FAILED
? result
: arithmetic.greaterThan(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "> error", xrt);
}
}
@Override
protected Object visit(final ASTLENode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.LTE, left, right);
return result != JexlEngine.TRY_FAILED
? result
: arithmetic.lessThanOrEqual(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "<= error", xrt);
}
}
@Override
protected Object visit(final ASTLTNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.LT, left, right);
return result != JexlEngine.TRY_FAILED
? result
: arithmetic.lessThan(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), "< error", xrt);
}
}
@Override
protected Object visit(final ASTSWNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
return operators.startsWith(node, "^=", left, right);
}
@Override
protected Object visit(final ASTNSWNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
return !operators.startsWith(node, "^!", left, right);
}
@Override
protected Object visit(final ASTEWNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
return operators.endsWith(node, "$=", left, right);
}
@Override
protected Object visit(final ASTNEWNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
return !operators.endsWith(node, "$!", left, right);
}
@Override
protected Object visit(final ASTERNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
// note the arguments inversion between 'in'/'matches' and 'contains'
// if x in y then y contains x
return operators.contains(node, "=~", right, left);
}
@Override
protected Object visit(final ASTNRNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
// note the arguments inversion between (not) 'in'/'matches' and (not) 'contains'
// if x not-in y then y not-contains x
return !operators.contains(node, "!~", right, left);
}
@Override
protected Object visit(final ASTRangeNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
return arithmetic.createRange(left, right);
} catch (final ArithmeticException xrt) {
throw new JexlException(findNullOperand(node, left, right), ".. error", xrt);
}
}
@Override
protected Object visit(final ASTUnaryMinusNode node, final Object data) {
// use cached value if literal
final Object value = node.jjtGetValue();
if (value != null && !(value instanceof JexlMethod)) {
return value;
}
final JexlNode valNode = node.jjtGetChild(0);
final Object val = valNode.jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.NEGATE, val);
if (result != JexlEngine.TRY_FAILED) {
return result;
}
Object number = arithmetic.negate(val);
// attempt to recoerce to literal class
// cache if number literal and negate is idempotent
if (number instanceof Number && valNode instanceof ASTNumberLiteral) {
number = arithmetic.narrowNumber((Number) number, ((ASTNumberLiteral) valNode).getLiteralClass());
if (arithmetic.isNegateStable()) {
node.jjtSetValue(number);
}
}
return number;
} catch (final ArithmeticException xrt) {
throw new JexlException(valNode, "- error", xrt);
}
}
@Override
protected Object visit(final ASTUnaryPlusNode node, final Object data) {
// use cached value if literal
final Object value = node.jjtGetValue();
if (value != null && !(value instanceof JexlMethod)) {
return value;
}
final JexlNode valNode = node.jjtGetChild(0);
final Object val = valNode.jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.POSITIVIZE, val);
if (result != JexlEngine.TRY_FAILED) {
return result;
}
final Object number = arithmetic.positivize(val);
if (valNode instanceof ASTNumberLiteral
&& number instanceof Number
&& arithmetic.isPositivizeStable()) {
node.jjtSetValue(number);
}
return number;
} catch (final ArithmeticException xrt) {
throw new JexlException(valNode, "- error", xrt);
}
}
@Override
protected Object visit(final ASTBitwiseComplNode node, final Object data) {
final Object arg = node.jjtGetChild(0).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.COMPLEMENT, arg);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.complement(arg);
} catch (final ArithmeticException xrt) {
throw new JexlException(node, "~ error", xrt);
}
}
@Override
protected Object visit(final ASTNotNode node, final Object data) {
final Object val = node.jjtGetChild(0).jjtAccept(this, data);
try {
final Object result = operators.tryOverload(node, JexlOperator.NOT, val);
return result != JexlEngine.TRY_FAILED ? result : arithmetic.not(val);
} catch (final ArithmeticException xrt) {
throw new JexlException(node, "! error", xrt);
}
}
private boolean testPredicate(final JexlNode node, final Object condition) {
final Object predicate = operators.tryOverload(node, JexlOperator.CONDITION, condition);
return arithmetic.testPredicate(predicate != JexlEngine.TRY_FAILED? predicate : condition);
}
@Override
protected Object visit(final ASTIfStatement node, final Object data) {
final int n = 0;
final int numChildren = node.jjtGetNumChildren();
try {
Object result = null;
// pairs of { conditions , 'then' statement }
for(int ifElse = 0; ifElse < (numChildren - 1); ifElse += 2) {
final JexlNode testNode = node.jjtGetChild(ifElse);
final Object condition = testNode.jjtAccept(this, null);
if (testPredicate(testNode, condition)) {
// first objectNode is true statement
return node.jjtGetChild(ifElse + 1).jjtAccept(this, null);
}
}
// if odd...
if ((numChildren & 1) == 1) {
// if there is an else, there are an odd number of children in the statement and it is the last child,
// execute it.
result = node.jjtGetChild(numChildren - 1).jjtAccept(this, null);
}
return result;
} catch (final ArithmeticException xrt) {
throw new JexlException(node.jjtGetChild(n), "if error", xrt);
}
}
@Override
protected Object visit(final ASTVar node, final Object data) {
final int symbol = node.getSymbol();
// if we have a var, we have a scope thus a frame
if (!options.isLexical() && !node.isLexical()) {
if (frame.has(symbol)) {
return frame.get(symbol);
}
} else if (!defineVariable(node, block)) {
return redefinedVariable(node, node.getName());
}
frame.set(symbol, null);
return null;
}
@Override
protected Object visit(final ASTBlock node, final Object data) {
final int cnt = node.getSymbolCount();
if (cnt <= 0) {
return visitBlock(node, data);
}
try {
block = new LexicalFrame(frame, block);
return visitBlock(node, data);
} finally {
block = block.pop();
}
}
/**
* Base visitation for blocks.
* @param node the block
* @param data the usual data
* @return the result of the last expression evaluation
*/
private Object visitBlock(final ASTBlock node, final Object data) {
final int numChildren = node.jjtGetNumChildren();
Object result = null;
for (int i = 0; i < numChildren; i++) {
cancelCheck(node);
result = node.jjtGetChild(i).jjtAccept(this, data);
}
return result;
}
@Override
protected Object visit(final ASTReturnStatement node, final Object data) {
final Object val = node.jjtGetChild(0).jjtAccept(this, data);
cancelCheck(node);
throw new JexlException.Return(node, null, val);
}
@Override
protected Object visit(final ASTContinue node, final Object data) {
throw new JexlException.Continue(node);
}
@Override
protected Object visit(final ASTBreak node, final Object data) {
throw new JexlException.Break(node);
}
@Override
protected Object visit(final ASTForeachStatement node, final Object data) {
return node.getLoopForm() == 0 ? forIterator(node, data) : forLoop(node, data);
}
private Object forIterator(final ASTForeachStatement node, final Object data) {
Object result = null;
/* first objectNode is the loop variable */
final ASTReference loopReference = (ASTReference) node.jjtGetChild(0);
final ASTIdentifier loopVariable = (ASTIdentifier) loopReference.jjtGetChild(0);
final int symbol = loopVariable.getSymbol();
final boolean lexical = loopVariable.isLexical() || options.isLexical() ;// && node.getSymbolCount() > 0;
final LexicalFrame locals = lexical? new LexicalFrame(frame, block) : null;
final boolean loopSymbol = symbol >= 0 && loopVariable instanceof ASTVar;
if (lexical) {
// create lexical frame
// it may be a local previously declared
if (loopSymbol && !defineVariable((ASTVar) loopVariable, locals)) {
return redefinedVariable(node, loopVariable.getName());
}
block = locals;
}
Object forEach = null;
try {
/* second objectNode is the variable to iterate */
final Object iterableValue = node.jjtGetChild(1).jjtAccept(this, data);
// make sure there is a value to iterate upon
if (iterableValue == null) {
return null;
}
/* last child node is the statement to execute */
final int numChildren = node.jjtGetNumChildren();
final JexlNode statement = numChildren >= 3 ? node.jjtGetChild(numChildren - 1) : null;
// get an iterator for the collection/array/etc. via the introspector.
forEach = operators.tryOverload(node, JexlOperator.FOR_EACH, iterableValue);
final Iterator<?> itemsIterator = forEach instanceof Iterator
? (Iterator<?>) forEach
: uberspect.getIterator(iterableValue);
if (itemsIterator == null) {
return null;
}
int cnt = 0;
while (itemsIterator.hasNext()) {
cancelCheck(node);
// reset loop variable
if (lexical && cnt++ > 0) {
// clean up but remain current
block.pop();
// unlikely to fail
if (loopSymbol && !defineVariable((ASTVar) loopVariable, locals)) {
return redefinedVariable(node, loopVariable.getName());
}
}
// set loopVariable to value of iterator
final Object value = itemsIterator.next();
if (symbol < 0) {
setContextVariable(node, loopVariable.getName(), value);
} else {
frame.set(symbol, value);
}
if (statement != null) {
try {
// execute statement
result = statement.jjtAccept(this, data);
} catch (final JexlException.Break stmtBreak) {
break;
} catch (final JexlException.Continue stmtContinue) {
//continue;
}
}
}
} finally {
// closeable iterator handling
closeIfSupported(forEach);
// restore lexical frame
if (lexical) {
block = block.pop();
}
}
return result;
}
private Object forLoop(final ASTForeachStatement node, final Object data) {
Object result = null;
int nc;
final int form = node.getLoopForm();
final LexicalFrame locals;
/* first child node might be the loop variable */
if ((form & 1) != 0) {
nc = 1;
final JexlNode init = node.jjtGetChild(0);
ASTVar loopVariable = null;
if (init instanceof ASTAssignment) {
final JexlNode child = init.jjtGetChild(0);
if (child instanceof ASTVar) {
loopVariable = (ASTVar) child;
}
} else if (init instanceof ASTVar){
loopVariable = (ASTVar) init;
}
if (loopVariable != null) {
final boolean lexical = loopVariable.isLexical() || options.isLexical();
locals = lexical ? new LexicalFrame(frame, block) : null;
if (locals != null) {
block = locals;
}
} else {
locals = null;
}
// initialize after eventual creation of local lexical frame
init.jjtAccept(this, data);
// other inits
for (JexlNode moreAssignment = node.jjtGetChild(nc);
moreAssignment instanceof ASTAssignment;
moreAssignment = node.jjtGetChild(++nc)) {
moreAssignment.jjtAccept(this, data);
}
} else {
locals = null;
nc = 0;
}
try {
// the loop condition
final JexlNode predicate = (form & 2) != 0? node.jjtGetChild(nc++) : null;
// the loop step
final JexlNode step = (form & 4) != 0? node.jjtGetChild(nc++) : null;
// last child is body
final JexlNode statement = (form & 8) != 0 ? node.jjtGetChild(nc) : null;
// while(predicate())...
while (predicate == null || testPredicate(predicate, predicate.jjtAccept(this, data))) {
cancelCheck(node);
// the body
if (statement != null) {
try {
// execute statement
result = statement.jjtAccept(this, data);
} catch (final JexlException.Break stmtBreak) {
break;
} catch (final JexlException.Continue stmtContinue) {
//continue;
}
}
// the step
if (step != null) {
step.jjtAccept(this, data);
}
}
} finally {
// restore lexical frame
if (locals != null) {
block = block.pop();
}
}
return result;
}
@Override
protected Object visit(final ASTWhileStatement node, final Object data) {
Object result = null;
/* first objectNode is the condition */
final JexlNode condition = node.jjtGetChild(0);
while (testPredicate(condition, condition.jjtAccept(this, data))) {
cancelCheck(node);
if (node.jjtGetNumChildren() > 1) {
try {
// execute statement
result = node.jjtGetChild(1).jjtAccept(this, data);
} catch (final JexlException.Break stmtBreak) {
break;
} catch (final JexlException.Continue stmtContinue) {
//continue;
}
}
}
return result;
}
@Override
protected Object visit(final ASTDoWhileStatement node, final Object data) {
Object result = null;
final int nc = node.jjtGetNumChildren();
/* last objectNode is the condition */
final JexlNode condition = node.jjtGetChild(nc - 1);
do {
cancelCheck(node);
if (nc > 1) {
try {
// execute statement
result = node.jjtGetChild(0).jjtAccept(this, data);
} catch (final JexlException.Break stmtBreak) {
break;
} catch (final JexlException.Continue stmtContinue) {
//continue;
}
}
} while (testPredicate(condition, condition.jjtAccept(this, data)));
return result;
}
@Override
protected Object visit(final ASTAndNode node, final Object data) {
/*
* The pattern for exception mgmt is to let the child*.jjtAccept out of the try/catch loop so that if one fails,
* the ex will traverse up to the interpreter. In cases where this is not convenient/possible, JexlException
* must be caught explicitly and rethrown.
*/
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
try {
final boolean leftValue = arithmetic.toBoolean(left);
if (!leftValue) {
return Boolean.FALSE;
}
} catch (final ArithmeticException xrt) {
throw new JexlException(node.jjtGetChild(0), "boolean coercion error", xrt);
}
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final boolean rightValue = arithmetic.toBoolean(right);
if (!rightValue) {
return Boolean.FALSE;
}
} catch (final ArithmeticException xrt) {
throw new JexlException(node.jjtGetChild(1), "boolean coercion error", xrt);
}
return Boolean.TRUE;
}
@Override
protected Object visit(final ASTOrNode node, final Object data) {
final Object left = node.jjtGetChild(0).jjtAccept(this, data);
try {
final boolean leftValue = arithmetic.toBoolean(left);
if (leftValue) {
return Boolean.TRUE;
}
} catch (final ArithmeticException xrt) {
throw new JexlException(node.jjtGetChild(0), "boolean coercion error", xrt);
}
final Object right = node.jjtGetChild(1).jjtAccept(this, data);
try {
final boolean rightValue = arithmetic.toBoolean(right);
if (rightValue) {
return Boolean.TRUE;
}
} catch (final ArithmeticException xrt) {
throw new JexlException(node.jjtGetChild(1), "boolean coercion error", xrt);
}
return Boolean.FALSE;
}
@Override
protected Object visit(final ASTNullLiteral node, final Object data) {
return null;
}
@Override
protected Object visit(final ASTTrueNode node, final Object data) {
return Boolean.TRUE;
}
@Override
protected Object visit(final ASTFalseNode node, final Object data) {
return Boolean.FALSE;
}
@Override
protected Object visit(final ASTNumberLiteral node, final Object data) {
if (data != null && node.isInteger()) {
return getAttribute(data, node.getLiteral(), node);
}
return node.getLiteral();
}
@Override
protected Object visit(final ASTStringLiteral node, final Object data) {
if (data != null) {
return getAttribute(data, node.getLiteral(), node);
}
return node.getLiteral();
}
@Override
protected Object visit(final ASTRegexLiteral node, final Object data) {
return node.getLiteral();
}
@Override
protected Object visit(final ASTArrayLiteral node, final Object data) {
final int childCount = node.jjtGetNumChildren();
final JexlArithmetic.ArrayBuilder ab = arithmetic.arrayBuilder(childCount);
boolean extended = false;
for (int i = 0; i < childCount; i++) {
cancelCheck(node);
final JexlNode child = node.jjtGetChild(i);
if (child instanceof ASTExtendedLiteral) {
extended = true;
} else {
final Object entry = node.jjtGetChild(i).jjtAccept(this, data);
ab.add(entry);
}
}
return ab.create(extended);
}
@Override
protected Object visit(final ASTExtendedLiteral node, final Object data) {
return node;
}
@Override
protected Object visit(final ASTSetLiteral node, final Object data) {
final int childCount = node.jjtGetNumChildren();
final JexlArithmetic.SetBuilder mb = arithmetic.setBuilder(childCount);
for (int i = 0; i < childCount; i++) {
cancelCheck(node);
final Object entry = node.jjtGetChild(i).jjtAccept(this, data);
mb.add(entry);
}
return mb.create();
}
@Override
protected Object visit(final ASTMapLiteral node, final Object data) {
final int childCount = node.jjtGetNumChildren();
final JexlArithmetic.MapBuilder mb = arithmetic.mapBuilder(childCount);
for (int i = 0; i < childCount; i++) {
cancelCheck(node);
final Object[] entry = (Object[]) (node.jjtGetChild(i)).jjtAccept(this, data);
mb.put(entry[0], entry[1]);
}
return mb.create();
}
@Override
protected Object visit(final ASTMapEntry node, final Object data) {
final Object key = node.jjtGetChild(0).jjtAccept(this, data);
final Object value = node.jjtGetChild(1).jjtAccept(this, data);
return new Object[]{key, value};
}
@Override
protected Object visit(final ASTTernaryNode node, final Object data) {
Object condition;
try {
condition = node.jjtGetChild(0).jjtAccept(this, data);
} catch(final JexlException xany) {
if (!(xany.getCause() instanceof JexlArithmetic.NullOperand)) {
throw xany;
}
condition = null;
}
// ternary as in "x ? y : z"
if (node.jjtGetNumChildren() == 3) {
if (condition != null && arithmetic.toBoolean(condition)) {
return node.jjtGetChild(1).jjtAccept(this, data);
}
return node.jjtGetChild(2).jjtAccept(this, data);
}
// elvis as in "x ?: z"
if (condition != null && arithmetic.toBoolean(condition)) {
return condition;
}
return node.jjtGetChild(1).jjtAccept(this, data);
}
@Override
protected Object visit(final ASTNullpNode node, final Object data) {
Object lhs;
try {
lhs = node.jjtGetChild(0).jjtAccept(this, data);
} catch(final JexlException xany) {
if (!(xany.getCause() instanceof JexlArithmetic.NullOperand)) {
throw xany;
}
lhs = null;
}
// null elision as in "x ?? z"
return lhs != null? lhs : node.jjtGetChild(1).jjtAccept(this, data);
}
@Override
protected Object visit(final ASTSizeFunction node, final Object data) {
try {
final Object val = node.jjtGetChild(0).jjtAccept(this, data);
return operators.size(node, val);
} catch(final JexlException xany) {
return 0;
}
}
@Override
protected Object visit(final ASTEmptyFunction node, final Object data) {
try {
final Object value = node.jjtGetChild(0).jjtAccept(this, data);
return operators.empty(node, value);
} catch(final JexlException xany) {
return true;
}
}
/**
* Runs a node.
* @param node the node
* @param data the usual data
* @return the return value
*/
protected Object visitLexicalNode(final JexlNode node, final Object data) {
block = new LexicalFrame(frame, null);
try {
return node.jjtAccept(this, data);
} finally {
block = block.pop();
}
}
/**
* Runs a closure.
* @param closure the closure
* @param data the usual data
* @return the closure return value
*/
protected Object runClosure(final Closure closure, final Object data) {
final ASTJexlScript script = closure.getScript();
// if empty script, nothing to evaluate
final int numChildren = script.jjtGetNumChildren();
if (numChildren == 0) {
return null;
}
block = new LexicalFrame(frame, block).defineArgs();
try {
final JexlNode body = script instanceof ASTJexlLambda
? script.jjtGetChild(numChildren - 1)
: script;
return interpret(body);
} finally {
block = block.pop();
}
}
@Override
protected Object visit(final ASTJexlScript script, final Object data) {
if (script instanceof ASTJexlLambda && !((ASTJexlLambda) script).isTopLevel()) {
final Closure closure = new Closure(this, (ASTJexlLambda) script);
// if the function is named, assign in the local frame
final JexlNode child0 = script.jjtGetChild(0);
if (child0 instanceof ASTVar) {
final ASTVar var = (ASTVar) child0;
this.visit(var, data);
final int symbol = var.getSymbol();
frame.set(symbol, closure);
// make the closure accessible to itself, ie capture the currently set variable after frame creation
closure.setCaptured(symbol, closure);
}
return closure;
}
block = new LexicalFrame(frame, block).defineArgs();
try {
final int numChildren = script.jjtGetNumChildren();
Object result = null;
for (int i = 0; i < numChildren; i++) {
final JexlNode child = script.jjtGetChild(i);
result = child.jjtAccept(this, data);
cancelCheck(child);
}
return result;
} finally {
block = block.pop();
}
}
@Override
protected Object visit(final ASTReferenceExpression node, final Object data) {
return node.jjtGetChild(0).jjtAccept(this, data);
}
@Override
protected Object visit(final ASTIdentifier identifier, final Object data) {
cancelCheck(identifier);
return data != null
? getAttribute(data, identifier.getName(), identifier)
: getVariable(frame, block, identifier);
}
@Override
protected Object visit(final ASTArrayAccess node, final Object data) {
// first objectNode is the identifier
Object object = data;
// can have multiple nodes - either an expression, integer literal or reference
final int numChildren = node.jjtGetNumChildren();
for (int i = 0; i < numChildren; i++) {
final JexlNode nindex = node.jjtGetChild(i);
if (object == null) {
return unsolvableProperty(nindex, stringifyProperty(nindex), false, null);
}
final Object index = nindex.jjtAccept(this, null);
cancelCheck(node);
object = getAttribute(object, index, nindex);
}
return object;
}
@Override
protected Object visit(final ASTQualifiedIdentifier node, final Object data) {
final String name = node.getName();
// try with local solver
String fqcn = fqcnSolver.resolveClassName(name);
if (fqcn != null) {
return fqcn;
}
// context may be solving class name ?
if (context instanceof JexlContext.ClassNameResolver) {
final JexlContext.ClassNameResolver resolver = (JexlContext.ClassNameResolver) context;
fqcn = resolver.resolveClassName(name);
if (fqcn != null) {
return fqcn;
}
}
return name;
}
/**
* Evaluates an access identifier based on the 2 main implementations;
* static (name or numbered identifier) or dynamic (jxlt).
* @param node the identifier access node
* @return the evaluated identifier
*/
private Object evalIdentifier(final ASTIdentifierAccess node) {
if (!(node instanceof ASTIdentifierAccessJxlt)) {
return node.getIdentifier();
}
final ASTIdentifierAccessJxlt accessJxlt = (ASTIdentifierAccessJxlt) node;
final String src = node.getName();
Throwable cause = null;
TemplateEngine.TemplateExpression expr = (TemplateEngine.TemplateExpression) accessJxlt.getExpression();
try {
if (expr == null) {
final TemplateEngine jxlt = jexl.jxlt();
expr = jxlt.parseExpression(node.jexlInfo(), src, frame != null ? frame.getScope() : null);
accessJxlt.setExpression(expr);
}
if (expr != null) {
final Object name = expr.evaluate(context, frame, options);
if (name != null) {
final Integer id = ASTIdentifierAccess.parseIdentifier(name.toString());
return id != null ? id : name;
}
}
} catch (final JxltEngine.Exception xjxlt) {
cause = xjxlt;
}
return node.isSafe() ? null : unsolvableProperty(node, src, true, cause);
}
@Override
protected Object visit(final ASTIdentifierAccess node, final Object data) {
if (data == null) {
return null;
}
final Object id = evalIdentifier(node);
return getAttribute(data, id, node);
}
@Override
protected Object visit(final ASTReference node, final Object data) {
cancelCheck(node);
final int numChildren = node.jjtGetNumChildren();
final JexlNode parent = node.jjtGetParent();
// pass first piece of data in and loop through children
Object object = null;
JexlNode objectNode = null;
JexlNode ptyNode = null;
StringBuilder ant = null;
boolean antish = !(parent instanceof ASTReference) && options.isAntish();
int v = 1;
main:
for (int c = 0; c < numChildren; c++) {
objectNode = node.jjtGetChild(c);
if (objectNode instanceof ASTMethodNode) {
antish = false;
if (object == null) {
// we may be performing a method call on an antish var
if (ant != null) {
final JexlNode child = objectNode.jjtGetChild(0);
if (child instanceof ASTIdentifierAccess) {
final int alen = ant.length();
ant.append('.');
ant.append(((ASTIdentifierAccess) child).getName());
object = context.get(ant.toString());
if (object != null) {
object = visit((ASTMethodNode) objectNode, object, context);
continue;
}
// remove method name from antish
ant.delete(alen, ant.length());
ptyNode = objectNode;
}
}
break;
}
} else if (objectNode instanceof ASTArrayAccess) {
antish = false;
if (object == null) {
ptyNode = objectNode;
break;
}
}
// attempt to evaluate the property within the object (visit(ASTIdentifierAccess node))
object = objectNode.jjtAccept(this, object);
cancelCheck(node);
if (object != null) {
// disallow mixing antish variable & bean with same root; avoid ambiguity
antish = false;
} else if (antish) {
// create first from first node
if (ant == null) {
// if we still have a null object, check for an antish variable
final JexlNode first = node.jjtGetChild(0);
if (!(first instanceof ASTIdentifier)) {
// not an identifier, not antish
ptyNode = objectNode;
break main;
}
final ASTIdentifier afirst = (ASTIdentifier) first;
ant = new StringBuilder(afirst.getName());
continue;
// skip the first node case since it was trialed in jjtAccept above and returned null
}
// catch up to current node
for (; v <= c; ++v) {
final JexlNode child = node.jjtGetChild(v);
if (!(child instanceof ASTIdentifierAccess)) {
// not an identifier, not antish
ptyNode = objectNode;
break main;
}
final ASTIdentifierAccess achild = (ASTIdentifierAccess) child;
if (achild.isSafe() || achild.isExpression()) {
break main;
}
ant.append('.');
ant.append(achild.getName());
}
// solve antish
object = context.get(ant.toString());
} else if (c != numChildren - 1) {
// only the last one may be null
ptyNode = c == 0 && numChildren > 1 ? node.jjtGetChild(1) : objectNode;
break; //
}
}
// dealing with null
if (object == null) {
if (ptyNode != null) {
if (ptyNode.isSafeLhs(isSafe())) {
return null;
}
if (ant != null) {
final String aname = ant.toString();
final boolean defined = isVariableDefined(frame, block, aname);
return unsolvableVariable(node, aname, !defined);
}
return unsolvableProperty(node,
stringifyProperty(ptyNode), ptyNode == objectNode, null);
}
if (antish) {
if (node.isSafeLhs(isSafe())) {
return null;
}
final String aname = ant != null ? ant.toString() : "?";
final boolean defined = isVariableDefined(frame, block, aname);
// defined but null; arg of a strict operator?
if (defined && !isStrictOperand(node)) {
return null;
}
return unsolvableVariable(node, aname, !defined);
}
}
return object;
}
@Override
protected Object visit(final ASTAssignment node, final Object data) {
return executeAssign(node, null, data);
}
@Override
protected Object visit(final ASTSetAddNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_ADD, data);
}
@Override
protected Object visit(final ASTSetSubNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_SUBTRACT, data);
}
@Override
protected Object visit(final ASTSetMultNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_MULTIPLY, data);
}
@Override
protected Object visit(final ASTSetDivNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_DIVIDE, data);
}
@Override
protected Object visit(final ASTSetModNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_MOD, data);
}
@Override
protected Object visit(final ASTSetAndNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_AND, data);
}
@Override
protected Object visit(final ASTSetOrNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_OR, data);
}
@Override
protected Object visit(final ASTSetXorNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_XOR, data);
}
@Override
protected Object visit(final ASTSetShiftLeftNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_SHIFTLEFT, data);
}
@Override
protected Object visit(final ASTSetShiftRightNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_SHIFTRIGHT, data);
}
@Override
protected Object visit(final ASTSetShiftRightUnsignedNode node, final Object data) {
return executeAssign(node, JexlOperator.SELF_SHIFTRIGHTU, data);
}
@Override
protected Object visit(final ASTGetDecrementNode node, final Object data) {
return executeAssign(node, JexlOperator.GET_AND_DECREMENT, data);
}
@Override
protected Object visit(final ASTGetIncrementNode node, final Object data) {
return executeAssign(node, JexlOperator.GET_AND_INCREMENT, data);
}
@Override
protected Object visit(final ASTDecrementGetNode node, final Object data) {
return executeAssign(node, JexlOperator.DECREMENT_AND_GET, data);
}
@Override
protected Object visit(final ASTIncrementGetNode node, final Object data) {
return executeAssign(node, JexlOperator.INCREMENT_AND_GET, data);
}
/**
* Executes an assignment with an optional side effect operator.
* @param node the node
* @param assignop the assignment operator or null if simply assignment
* @param data the data
* @return the left hand side
*/
protected Object executeAssign(final JexlNode node, final JexlOperator assignop, final Object data) { // CSOFF: MethodLength
cancelCheck(node);
// left contains the reference to assign to
final JexlNode left = node.jjtGetChild(0);
final ASTIdentifier var;
Object object = null;
final int symbol;
// check var decl with assign is ok
if (left instanceof ASTIdentifier) {
var = (ASTIdentifier) left;
symbol = var.getSymbol();
if (symbol >= 0 && (var.isLexical() || options.isLexical())) {
if (var instanceof ASTVar) {
if (!defineVariable((ASTVar) var, block)) {
return redefinedVariable(var, var.getName());
}
} else if (var.isShaded() && (var.isLexical() || options.isLexicalShade())) {
return undefinedVariable(var, var.getName());
}
}
} else {
var = null;
symbol = -1;
}
boolean antish = options.isAntish();
// 0: determine initial object & property:
final int last = left.jjtGetNumChildren() - 1;
// right is the value expression to assign
final Object right = node.jjtGetNumChildren() < 2? null: node.jjtGetChild(1).jjtAccept(this, data);
// actual value to return, right in most cases
Object actual = right;
// a (var?) v = ... expression
if (var != null) {
if (symbol >= 0) {
// check we are not assigning a symbol itself
if (last < 0) {
if (assignop == null) {
// make the closure accessible to itself, ie capture the currently set variable after frame creation
if (right instanceof Closure) {
((Closure) right).setCaptured(symbol, right);
}
frame.set(symbol, right);
} else {
// go through potential overload
final Object self = getVariable(frame, block, var);
final Consumer<Object> f = r -> frame.set(symbol, r);
actual = operators.tryAssignOverload(node, assignop, f, self, right);
}
return actual; // 1
}
object = getVariable(frame, block, var);
// top level is a symbol, can not be an antish var
antish = false;
} else {
// check we are not assigning direct global
final String name = var.getName();
if (last < 0) {
if (assignop == null) {
setContextVariable(node, name, right);
} else {
// go through potential overload
final Object self = context.get(name);
final Consumer<Object> f = r -> setContextVariable(node, name, r);
actual = operators.tryAssignOverload(node, assignop, f, self, right);
}
return actual; // 2
}
object = context.get(name);
// top level accesses object, can not be an antish var
if (object != null) {
antish = false;
}
}
} else if (!(left instanceof ASTReference)) {
throw new JexlException(left, "illegal assignment form 0");
}
// 1: follow children till penultimate, resolve dot/array
JexlNode objectNode = null;
StringBuilder ant = null;
int v = 1;
// start at 1 if symbol
main: for (int c = symbol >= 0 ? 1 : 0; c < last; ++c) {
objectNode = left.jjtGetChild(c);
object = objectNode.jjtAccept(this, object);
if (object != null) {
// disallow mixing antish variable & bean with same root; avoid ambiguity
antish = false;
} else if (antish) {
// initialize if first time
if (ant == null) {
final JexlNode first = left.jjtGetChild(0);
final ASTIdentifier firstId = first instanceof ASTIdentifier
? (ASTIdentifier) first
: null;
if ((firstId == null) || (firstId.getSymbol() >= 0)) {
// ant remains null, object is null, stop solving
antish = false;
break main;
}
ant = new StringBuilder(firstId.getName());
}
// catch up to current child
for (; v <= c; ++v) {
final JexlNode child = left.jjtGetChild(v);
final ASTIdentifierAccess aid = child instanceof ASTIdentifierAccess
? (ASTIdentifierAccess) child
: null;
// remain antish only if unsafe navigation
if ((aid == null) || aid.isSafe() || aid.isExpression()) {
antish = false;
break main;
}
ant.append('.');
ant.append(aid.getName());
}
// solve antish
object = context.get(ant.toString());
} else {
throw new JexlException(objectNode, "illegal assignment form");
}
}
// 2: last objectNode will perform assignment in all cases
JexlNode propertyNode = left.jjtGetChild(last);
final ASTIdentifierAccess propertyId = propertyNode instanceof ASTIdentifierAccess
? (ASTIdentifierAccess) propertyNode
: null;
final Object property;
if (propertyId != null) {
// deal with creating/assigning antish variable
if (antish && ant != null && object == null && !propertyId.isSafe() && !propertyId.isExpression()) {
ant.append('.');
ant.append(propertyId.getName());
final String name = ant.toString();
if (assignop == null) {
setContextVariable(propertyNode, name, right);
} else {
final Object self = context.get(ant.toString());
final JexlNode pnode = propertyNode;
final Consumer<Object> assign = r -> setContextVariable(pnode, name, r);
actual = operators.tryAssignOverload(node, assignop, assign, self, right);
}
return actual; // 3
}
// property of an object ?
property = evalIdentifier(propertyId);
} else if (propertyNode instanceof ASTArrayAccess) {
// can have multiple nodes - either an expression, integer literal or reference
final int numChildren = propertyNode.jjtGetNumChildren() - 1;
for (int i = 0; i < numChildren; i++) {
final JexlNode nindex = propertyNode.jjtGetChild(i);
final Object index = nindex.jjtAccept(this, null);
object = getAttribute(object, index, nindex);
}
propertyNode = propertyNode.jjtGetChild(numChildren);
property = propertyNode.jjtAccept(this, null);
} else {
throw new JexlException(objectNode, "illegal assignment form");
}
// we may have a null property as in map[null], no check needed.
// we can not *have* a null object though.
if (object == null) {
// no object, we fail
return unsolvableProperty(objectNode, "<null>.<?>", true, null);
}
// 3: one before last, assign
if (assignop == null) {
setAttribute(object, property, right, propertyNode);
} else {
final Object self = getAttribute(object, property, propertyNode);
final Object o = object;
final JexlNode n = propertyNode;
final Consumer<Object> assign = r -> setAttribute(o, property, r, n);
actual = operators.tryAssignOverload(node, assignop, assign, self, right);
}
return actual;
}
@Override
protected Object visit(final ASTDefineVars node, final Object data) {
final int argc = node.jjtGetNumChildren();
Object result = null;
for (int i = 0; i < argc; i++) {
result = node.jjtGetChild(i).jjtAccept(this, data);
}
return result;
}
@Override
protected Object[] visit(final ASTArguments node, final Object data) {
final int argc = node.jjtGetNumChildren();
final Object[] argv = new Object[argc];
for (int i = 0; i < argc; i++) {
argv[i] = node.jjtGetChild(i).jjtAccept(this, data);
}
return argv;
}
@Override
protected Object visit(final ASTMethodNode node, final Object data) {
return visit(node, null, data);
}
/**
* Execute a method call, ie syntactically written as name.call(...).
* @param node the actual method call node
* @param antish non-null when name.call is an antish variable
* @param data the context
* @return the method call result
*/
private Object visit(final ASTMethodNode node, final Object antish, final Object data) {
Object object = antish;
// left contains the reference to the method
final JexlNode methodNode = node.jjtGetChild(0);
Object method;
// 1: determine object and method or functor
if (methodNode instanceof ASTIdentifierAccess) {
method = methodNode;
if (object == null) {
object = data;
if (object == null) {
// no object, we fail
return node.isSafeLhs(isSafe())
? null
: unsolvableMethod(methodNode, "<null>.<?>(...)");
}
} else {
// edge case of antish var used as functor
method = object;
}
} else {
method = methodNode.jjtAccept(this, data);
}
Object result = method;
for (int a = 1; a < node.jjtGetNumChildren(); ++a) {
if (result == null) {
// no method, we fail// variable unknown in context and not a local
return node.isSafeLhs(isSafe())
? null
: unsolvableMethod(methodNode, "<?>.<null>(...)");
}
final ASTArguments argNode = (ASTArguments) node.jjtGetChild(a);
result = call(node, object, result, argNode);
object = result;
}
return result;
}
@Override
protected Object visit(final ASTFunctionNode node, final Object data) {
final ASTIdentifier functionNode = (ASTIdentifier) node.jjtGetChild(0);
final String nsid = functionNode.getNamespace();
final Object namespace = (nsid != null)? resolveNamespace(nsid, node) : context;
final ASTArguments argNode = (ASTArguments) node.jjtGetChild(1);
return call(node, namespace, functionNode, argNode);
}
/**
* Calls a method (or function).
* <p>
* Method resolution is a follows:
* 1 - attempt to find a method in the target passed as parameter;
* 2 - if this fails, seeks a JexlScript or JexlMethod or a duck-callable* as a property of that target;
* 3 - if this fails, narrow the arguments and try again 1
* 4 - if this fails, seeks a context or arithmetic method with the proper name taking the target as first argument;
* </p>
* *duck-callable: an object where a "call" function exists
*
* @param node the method node
* @param target the target of the method, what it should be invoked upon
* @param funcNode the object carrying the method or function or the method identifier
* @param argNode the node carrying the arguments
* @return the result of the method invocation
*/
protected Object call(final JexlNode node, final Object target, final Object funcNode, final ASTArguments argNode) {
cancelCheck(node);
// evaluate the arguments
final Object[] argv = visit(argNode, null);
final String methodName;
boolean cacheable = cache;
boolean isavar = false;
Object functor = funcNode;
// get the method name if identifier
if (functor instanceof ASTIdentifier) {
// function call, target is context or namespace (if there was one)
final ASTIdentifier methodIdentifier = (ASTIdentifier) functor;
final int symbol = methodIdentifier.getSymbol();
methodName = methodIdentifier.getName();
functor = null;
// is it a global or local variable ?
if (target == context) {
if (frame != null && frame.has(symbol)) {
functor = frame.get(symbol);
isavar = functor != null;
} else if (context.has(methodName)) {
functor = context.get(methodName);
isavar = functor != null;
}
// name is a variable, can't be cached
cacheable &= !isavar;
}
} else if (functor instanceof ASTIdentifierAccess) {
// a method call on target
methodName = ((ASTIdentifierAccess) functor).getName();
functor = null;
cacheable = true;
} else if (functor != null) {
// ...(x)(y)
methodName = null;
cacheable = false;
} else if (!node.isSafeLhs(isSafe())) {
return unsolvableMethod(node, "?(...)");
} else {
// safe lhs
return null;
}
// solving the call site
final CallDispatcher call = new CallDispatcher(node, cacheable);
try {
// do we have a cached version method/function name ?
final Object eval = call.tryEval(target, methodName, argv);
if (JexlEngine.TRY_FAILED != eval) {
return eval;
}
boolean functorp = false;
boolean narrow = false;
// pseudo loop to try acquiring methods without and with argument narrowing
while (true) {
call.narrow = narrow;
// direct function or method call
if (functor == null || functorp) {
// try a method or function from context
if (call.isTargetMethod(target, methodName, argv)) {
return call.eval(methodName);
}
if (target == context) {
// solve 'null' namespace
final Object namespace = resolveNamespace(null, node);
if (namespace != null
&& namespace != context
&& call.isTargetMethod(namespace, methodName, argv)) {
return call.eval(methodName);
}
// do not try context function since this was attempted
// 10 lines above...; solve as an arithmetic function
if (call.isArithmeticMethod(methodName, argv)) {
return call.eval(methodName);
}
// could not find a method, try as a property of a non-context target (performed once)
} else {
// try prepending target to arguments and look for
// applicable method in context...
final Object[] pargv = functionArguments(target, narrow, argv);
if (call.isContextMethod(methodName, pargv)) {
return call.eval(methodName);
}
// ...or arithmetic
if (call.isArithmeticMethod(methodName, pargv)) {
return call.eval(methodName);
}
// the method may also be a functor stored in a property of the target
if (!narrow) {
final JexlPropertyGet get = uberspect.getPropertyGet(target, methodName);
if (get != null) {
functor = get.tryInvoke(target, methodName);
functorp = functor != null;
}
}
}
}
// this may happen without the above when we are chaining call like x(a)(b)
// or when a var/symbol or antish var is used as a "function" name
if (functor != null) {
// lambda, script or jexl method will do
if (functor instanceof JexlScript) {
return ((JexlScript) functor).execute(context, argv);
}
if (functor instanceof JexlMethod) {
return ((JexlMethod) functor).invoke(target, argv);
}
final String mCALL = "call";
// may be a generic callable, try a 'call' method
if (call.isTargetMethod(functor, mCALL, argv)) {
return call.eval(mCALL);
}
// functor is a var, may be method is a global one ?
if (isavar) {
if (call.isContextMethod(methodName, argv)) {
return call.eval(methodName);
}
if (call.isArithmeticMethod(methodName, argv)) {
return call.eval(methodName);
}
}
// try prepending functor to arguments and look for
// context or arithmetic function called 'call'
final Object[] pargv = functionArguments(functor, narrow, argv);
if (call.isContextMethod(mCALL, pargv)) {
return call.eval(mCALL);
}
if (call.isArithmeticMethod(mCALL, pargv)) {
return call.eval(mCALL);
}
}
// if we did not find an exact method by name and we haven't tried yet,
// attempt to narrow the parameters and if this succeeds, try again in next loop
if (narrow || !arithmetic.narrowArguments(argv)) {
break;
}
narrow = true;
// continue;
}
} catch (final JexlException.Method xmethod) {
// ignore and handle at end; treat as an inner discover that fails
} catch (final JexlException.TryFailed xany) {
throw invocationException(node, methodName, xany);
} catch (final JexlException xthru) {
throw xthru;
} catch (final Exception xany) {
throw invocationException(node, methodName, xany);
}
// we have either evaluated and returned or no method was found
return node.isSafeLhs(isSafe())
? null
: unsolvableMethod(node, methodName, argv);
}
@Override
protected Object visit(final ASTConstructorNode node, final Object data) {
if (isCancelled()) {
throw new JexlException.Cancel(node);
}
// first child is class or class name
final Object target = node.jjtGetChild(0).jjtAccept(this, data);
// get the ctor args
final int argc = node.jjtGetNumChildren() - 1;
Object[] argv = new Object[argc];
for (int i = 0; i < argc; i++) {
argv[i] = node.jjtGetChild(i + 1).jjtAccept(this, data);
}
try {
final boolean cacheable = cache;
// attempt to reuse last funcall cached in volatile JexlNode.value
if (cacheable) {
final Object cached = node.jjtGetValue();
if (cached instanceof Funcall) {
final Object eval = ((Funcall) cached).tryInvoke(this, null, target, argv);
if (JexlEngine.TRY_FAILED != eval) {
return eval;
}
}
}
boolean narrow = false;
Funcall funcall = null;
JexlMethod ctor;
while (true) {
// try as stated
ctor = uberspect.getConstructor(target, argv);
if (ctor != null) {
if (cacheable && ctor.isCacheable()) {
funcall = new Funcall(ctor, narrow);
}
break;
}
// try with prepending context as first argument
final Object[] nargv = callArguments(context, narrow, argv);
ctor = uberspect.getConstructor(target, nargv);
if (ctor != null) {
if (cacheable && ctor.isCacheable()) {
funcall = new ContextualCtor(ctor, narrow);
}
argv = nargv;
break;
}
// if we did not find an exact method by name and we haven't tried yet,
// attempt to narrow the parameters and if this succeeds, try again in next loop
if (!narrow && arithmetic.narrowArguments(argv)) {
narrow = true;
continue;
}
// we are done trying
break;
}
// we have either evaluated and returned or might have found a ctor
if (ctor != null) {
final Object eval = ctor.invoke(target, argv);
// cache executor in volatile JexlNode.value
if (funcall != null) {
node.jjtSetValue(funcall);
}
return eval;
}
final String tstr = target != null ? target.toString() : "?";
return unsolvableMethod(node, tstr, argv);
} catch (final JexlException.Method xmethod) {
throw xmethod;
} catch (final Exception xany) {
final String tstr = target != null ? target.toString() : "?";
throw invocationException(node, tstr, xany);
}
}
@Override
protected Object visit(final ASTJxltLiteral node, final Object data) {
TemplateEngine.TemplateExpression tp = (TemplateEngine.TemplateExpression) node.jjtGetValue();
if (tp == null) {
final TemplateEngine jxlt = jexl.jxlt();
JexlInfo info = node.jexlInfo();
if (this.block != null) {
info = new JexlNode.Info(node, info);
}
tp = jxlt.parseExpression(info, node.getLiteral(), frame != null ? frame.getScope() : null);
node.jjtSetValue(tp);
}
if (tp != null) {
return tp.evaluate(context, frame, options);
}
return null;
}
@Override
protected Object visit(final ASTAnnotation node, final Object data) {
throw new UnsupportedOperationException(ASTAnnotation.class.getName() + ": Not supported.");
}
@Override
protected Object visit(final ASTAnnotatedStatement node, final Object data) {
return processAnnotation(node, 0, data);
}
/**
* An annotated call.
*/
public class AnnotatedCall implements Callable<Object> {
/** The statement. */
private final ASTAnnotatedStatement stmt;
/** The child index. */
private final int index;
/** The data. */
private final Object data;
/** Tracking whether we processed the annotation. */
private boolean processed = false;
/**
* Simple ctor.
* @param astmt the statement
* @param aindex the index
* @param adata the data
*/
AnnotatedCall(final ASTAnnotatedStatement astmt, final int aindex, final Object adata) {
stmt = astmt;
index = aindex;
data = adata;
}
@Override
public Object call() throws Exception {
processed = true;
try {
return processAnnotation(stmt, index, data);
} catch (JexlException.Return | JexlException.Break | JexlException.Continue xreturn) {
return xreturn;
}
}
/**
* @return whether the statement has been processed
*/
public boolean isProcessed() {
return processed;
}
/**
* @return the actual statement.
*/
public Object getStatement() {
return stmt;
}
}
/**
* Processes an annotated statement.
* @param stmt the statement
* @param index the index of the current annotation being processed
* @param data the contextual data
* @return the result of the statement block evaluation
*/
protected Object processAnnotation(final ASTAnnotatedStatement stmt, final int index, final Object data) {
// are we evaluating the block ?
final int last = stmt.jjtGetNumChildren() - 1;
if (index == last) {
final JexlNode cblock = stmt.jjtGetChild(last);
// if the context has changed, might need a new interpreter
final JexlArithmetic jexla = arithmetic.options(context);
if (jexla == arithmetic) {
return cblock.jjtAccept(Interpreter.this, data);
}
if (!arithmetic.getClass().equals(jexla.getClass()) && logger.isWarnEnabled()) {
logger.warn("expected arithmetic to be " + arithmetic.getClass().getSimpleName()
+ ", got " + jexla.getClass().getSimpleName()
);
}
final Interpreter ii = new Interpreter(Interpreter.this, jexla);
final Object r = cblock.jjtAccept(ii, data);
if (ii.isCancelled()) {
Interpreter.this.cancel();
}
return r;
}
// tracking whether we processed the annotation
final AnnotatedCall jstmt = new AnnotatedCall(stmt, index + 1, data);
// the annotation node and name
final ASTAnnotation anode = (ASTAnnotation) stmt.jjtGetChild(index);
final String aname = anode.getName();
// evaluate the arguments
final Object[] argv = anode.jjtGetNumChildren() > 0
? visit((ASTArguments) anode.jjtGetChild(0), null) : null;
// wrap the future, will recurse through annotation processor
Object result;
try {
result = processAnnotation(aname, argv, jstmt);
// not processing an annotation is an error
if (!jstmt.isProcessed()) {
return annotationError(anode, aname, null);
}
} catch (final JexlException xany) {
throw xany;
} catch (final Exception xany) {
return annotationError(anode, aname, xany);
}
// the caller may return a return, break or continue
if (result instanceof JexlException) {
throw (JexlException) result;
}
return result;
}
/**
* Delegates the annotation processing to the JexlContext if it is an AnnotationProcessor.
* @param annotation the annotation name
* @param args the annotation arguments
* @param stmt the statement / block that was annotated
* @return the result of statement.call()
* @throws Exception if anything goes wrong
*/
protected Object processAnnotation(final String annotation, final Object[] args, final Callable<Object> stmt) throws Exception {
return context instanceof JexlContext.AnnotationProcessor
? ((JexlContext.AnnotationProcessor) context).processAnnotation(annotation, args, stmt)
: stmt.call();
}
}