org.springframework.expression.spel.ast.OpMinus Maven / Gradle / Ivy
/*
* Copyright 2002-2022 the original author or authors.
*
* Licensed 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
*
* https://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.
*/
package org.springframework.expression.spel.ast;
import java.math.BigDecimal;
import java.math.BigInteger;
import org.springframework.asm.MethodVisitor;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.Operation;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.CodeFlow;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.util.Assert;
import org.springframework.util.NumberUtils;
/**
* The minus operator supports:
*
* - subtraction of numbers
*
- subtraction of an int from a string of one character
* (effectively decreasing that character), so 'd'-3='a'
*
*
* It can be used as a unary operator for numbers.
* The standard promotions are performed when the operand types vary (double-int=double).
* For other options it defers to the registered overloader.
*
* @author Andy Clement
* @author Juergen Hoeller
* @author Giovanni Dall'Oglio Risso
* @author Sam Brannen
* @since 3.0
*/
public class OpMinus extends Operator {
public OpMinus(int startPos, int endPos, SpelNodeImpl... operands) {
super("-", startPos, endPos, operands);
}
@Override
public TypedValue getValueInternal(ExpressionState state) throws EvaluationException {
SpelNodeImpl leftOp = getLeftOperand();
if (this.children.length < 2) { // if only one operand, then this is unary minus
Object operand = leftOp.getValueInternal(state).getValue();
if (operand instanceof Number number) {
if (number instanceof BigDecimal bigDecimal) {
return new TypedValue(bigDecimal.negate());
}
else if (number instanceof BigInteger bigInteger) {
return new TypedValue(bigInteger.negate());
}
else if (number instanceof Double) {
this.exitTypeDescriptor = "D";
return new TypedValue(0 - number.doubleValue());
}
else if (number instanceof Float) {
this.exitTypeDescriptor = "F";
return new TypedValue(0 - number.floatValue());
}
else if (number instanceof Long) {
this.exitTypeDescriptor = "J";
return new TypedValue(0 - number.longValue());
}
else if (number instanceof Integer) {
this.exitTypeDescriptor = "I";
return new TypedValue(0 - number.intValue());
}
else if (number instanceof Short) {
return new TypedValue(0 - number.shortValue());
}
else if (number instanceof Byte) {
return new TypedValue(0 - number.byteValue());
}
else {
// Unknown Number subtype -> best guess is double subtraction
return new TypedValue(0 - number.doubleValue());
}
}
return state.operate(Operation.SUBTRACT, operand, null);
}
Object left = leftOp.getValueInternal(state).getValue();
Object right = getRightOperand().getValueInternal(state).getValue();
if (left instanceof Number leftNumber && right instanceof Number rightNumber) {
if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) {
BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class);
BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class);
return new TypedValue(leftBigDecimal.subtract(rightBigDecimal));
}
else if (leftNumber instanceof Double || rightNumber instanceof Double) {
this.exitTypeDescriptor = "D";
return new TypedValue(leftNumber.doubleValue() - rightNumber.doubleValue());
}
else if (leftNumber instanceof Float || rightNumber instanceof Float) {
this.exitTypeDescriptor = "F";
return new TypedValue(leftNumber.floatValue() - rightNumber.floatValue());
}
else if (leftNumber instanceof BigInteger || rightNumber instanceof BigInteger) {
BigInteger leftBigInteger = NumberUtils.convertNumberToTargetClass(leftNumber, BigInteger.class);
BigInteger rightBigInteger = NumberUtils.convertNumberToTargetClass(rightNumber, BigInteger.class);
return new TypedValue(leftBigInteger.subtract(rightBigInteger));
}
else if (leftNumber instanceof Long || rightNumber instanceof Long) {
this.exitTypeDescriptor = "J";
return new TypedValue(leftNumber.longValue() - rightNumber.longValue());
}
else if (CodeFlow.isIntegerForNumericOp(leftNumber) || CodeFlow.isIntegerForNumericOp(rightNumber)) {
this.exitTypeDescriptor = "I";
return new TypedValue(leftNumber.intValue() - rightNumber.intValue());
}
else {
// Unknown Number subtypes -> best guess is double subtraction
return new TypedValue(leftNumber.doubleValue() - rightNumber.doubleValue());
}
}
if (left instanceof String theString && right instanceof Integer theInteger && theString.length() == 1) {
// Implements character - int (ie. b - 1 = a)
return new TypedValue(Character.toString((char) (theString.charAt(0) - theInteger)));
}
return state.operate(Operation.SUBTRACT, left, right);
}
@Override
public String toStringAST() {
if (this.children.length < 2) { // unary minus
return "-" + getLeftOperand().toStringAST();
}
return super.toStringAST();
}
@Override
public SpelNodeImpl getRightOperand() {
if (this.children.length < 2) {
throw new IllegalStateException("No right operand");
}
return this.children[1];
}
@Override
public boolean isCompilable() {
if (!getLeftOperand().isCompilable()) {
return false;
}
if (this.children.length > 1) {
if (!getRightOperand().isCompilable()) {
return false;
}
}
return (this.exitTypeDescriptor != null);
}
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
getLeftOperand().generateCode(mv, cf);
String leftDesc = getLeftOperand().exitTypeDescriptor;
String exitDesc = this.exitTypeDescriptor;
Assert.state(exitDesc != null, "No exit type descriptor");
char targetDesc = exitDesc.charAt(0);
CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, leftDesc, targetDesc);
if (this.children.length > 1) {
cf.enterCompilationScope();
getRightOperand().generateCode(mv, cf);
String rightDesc = getRightOperand().exitTypeDescriptor;
cf.exitCompilationScope();
CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, rightDesc, targetDesc);
switch (targetDesc) {
case 'I' -> mv.visitInsn(ISUB);
case 'J' -> mv.visitInsn(LSUB);
case 'F' -> mv.visitInsn(FSUB);
case 'D' -> mv.visitInsn(DSUB);
default -> throw new IllegalStateException(
"Unrecognized exit type descriptor: '" + this.exitTypeDescriptor + "'");
}
}
else {
switch (targetDesc) {
case 'I' -> mv.visitInsn(INEG);
case 'J' -> mv.visitInsn(LNEG);
case 'F' -> mv.visitInsn(FNEG);
case 'D' -> mv.visitInsn(DNEG);
default -> throw new IllegalStateException(
"Unrecognized exit type descriptor: '" + this.exitTypeDescriptor + "'");
}
}
cf.pushDescriptor(this.exitTypeDescriptor);
}
}