Package org.springframework.expression.spel.ast

Class OpMinus

java.lang.Object

org.springframework.expression.spel.ast.SpelNodeImpl

org.springframework.expression.spel.ast.Operator

org.springframework.expression.spel.ast.OpMinus

All Implemented Interfaces:

Opcodes, SpelNode

public class OpMinus
extends Operator

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.

Since:

3.0

Author:

Andy Clement, Juergen Hoeller, Giovanni Dall'Oglio Risso, Sam Brannen, Semyon Danilov

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.expression.spel.ast.Operator

Operator.DescriptorComparison

Field Summary

Fields inherited from class org.springframework.expression.spel.ast.Operator

leftActualDescriptor, rightActualDescriptor

Fields inherited from class org.springframework.expression.spel.ast.SpelNodeImpl

children, exitTypeDescriptor

Fields inherited from interface org.springframework.asm.Opcodes

AALOAD, AASTORE, ACC_ABSTRACT, ACC_ANNOTATION, ACC_BRIDGE, ACC_DEPRECATED, ACC_ENUM, ACC_FINAL, ACC_INTERFACE, ACC_MANDATED, ACC_MODULE, ACC_NATIVE, ACC_OPEN, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_RECORD, ACC_STATIC, ACC_STATIC_PHASE, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_TRANSITIVE, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASM10_EXPERIMENTAL, ASM4, ASM5, ASM6, ASM7, ASM8, ASM9, ASTORE, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DMUL, DNEG, DOUBLE, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F_APPEND, F_CHOP, F_FULL, F_NEW, F_SAME, F_SAME1, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, FLOAT, FMUL, FNEG, FREM, FRETURN, FSTORE, FSUB, GETFIELD, GETSTATIC, GOTO, H_GETFIELD, H_GETSTATIC, H_INVOKEINTERFACE, H_INVOKESPECIAL, H_INVOKESTATIC, H_INVOKEVIRTUAL, H_NEWINVOKESPECIAL, H_PUTFIELD, H_PUTSTATIC, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, IMUL, INEG, INSTANCEOF, INTEGER, INVOKEDYNAMIC, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISUB, IUSHR, IXOR, JSR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDIV, LLOAD, LMUL, LNEG, LONG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, NULL, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SOURCE_DEPRECATED, SOURCE_MASK, SWAP, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH, TOP, UNINITIALIZED_THIS, V_PREVIEW, V1_1, V1_2, V1_3, V1_4, V1_5, V1_6, V1_7, V1_8, V10, V11, V12, V13, V14, V15, V16, V17, V18, V19, V20, V21, V22, V23, V24, V9

Constructor Summary

Constructors

Constructor	Description
OpMinus(int startPos, int endPos, SpelNodeImpl... operands)

Method Summary

Modifier and Type	Method	Description
void	generateCode(MethodVisitor mv, CodeFlow cf)	Generate the bytecode for this node into the supplied MethodVisitor.
SpelNodeImpl	getRightOperand()
TypedValue	getValueInternal(ExpressionState state)
boolean	isCompilable()	Determine if this node can be compiled to bytecode.
boolean	isNegativeNumberLiteral()	Determine if this operator is a unary minus and its child is a number literal.
String	toStringAST()	String format for all operators is the same '(' [operand] [operator] [operand] ')'.

Methods inherited from class org.springframework.expression.spel.ast.Operator

equalityCheck, generateComparisonCode, getLeftOperand, getOperatorName, isCompilableOperatorUsingNumerics

Methods inherited from class org.springframework.expression.spel.ast.SpelNodeImpl

generateCodeForArgument, generateCodeForArguments, generateCodeForArguments, getChild, getChildCount, getEndPosition, getExitDescriptor, getObjectClass, getStartPosition, getTypedValue, getValue, getValue, getValueRef, isNullSafe, isWritable, nextChildIs, setValue, setValueInternal

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

OpMinus

public OpMinus(int startPos,
 int endPos,
 SpelNodeImpl... operands)

Method Details

isNegativeNumberLiteral

public boolean isNegativeNumberLiteral()

Determine if this operator is a unary minus and its child is a number literal.

Returns:

true if it is a negative number literal

Since:

6.1

getValueInternal

public TypedValue getValueInternal(ExpressionState state)
                            throws EvaluationException

Specified by:

getValueInternal in class SpelNodeImpl

Throws:

EvaluationException

toStringAST

public String toStringAST()

Description copied from class: Operator

String format for all operators is the same '(' [operand] [operator] [operand] ')'.

Specified by:

toStringAST in interface SpelNode

Overrides:

toStringAST in class Operator

Returns:

the string form

getRightOperand

public SpelNodeImpl getRightOperand()

Overrides:

getRightOperand in class Operator

isCompilable

public boolean isCompilable()

Description copied from interface: SpelNode

Determine if this node can be compiled to bytecode.

The reasoning in each node may be different but will typically involve checking whether the exit type descriptor of the node is known and any relevant child nodes are compilable.

The default implementation returns false.

If you override this method, you must also override SpelNode.generateCode(MethodVisitor, CodeFlow).

Returns:

true if this node can be compiled to bytecode

See Also:

• SpelNode.generateCode(MethodVisitor, CodeFlow)

generateCode

public void generateCode(MethodVisitor mv,
 CodeFlow cf)

Description copied from interface: SpelNode

Generate the bytecode for this node into the supplied MethodVisitor.

Context information about the current expression being compiled is available in the supplied CodeFlow object — for example, information about the type of the object currently on the stack.

This method will not be invoked unless SpelNode.isCompilable() returns true.

The default implementation throws an IllegalStateException since SpelNode.isCompilable() returns false by default.

If you override this method, you must also override SpelNode.isCompilable().

Parameters:

mv - the ASM MethodVisitor into which code should be generated

cf - a context object with information about what is on the stack

See Also:

• SpelNode.isCompilable()