org.jsimpledb.parse.expr

Interface Value

All Known Subinterfaces:

LValue

All Known Implementing Classes:

AbstractLValue, AbstractValue, BeanPropertyValue, ConstValue, FieldValue, InstanceFieldValue, JFieldValue, JSimpleFieldValue, MutableBeanPropertyValue, SimpleFieldValue, StaticFieldValue, ValueValue, VarValue

public interface Value

Holds a value for use during expression evaluation.

Field Summary

Fields

Modifier and Type	Field and Description
static int	EQ Flag mask value for use with compare().
static int	GT Flag mask value for use with compare().
static int	LT Flag mask value for use with compare().
static Value	NO_VALUE Special value that can be used to indicate "no value" in certain situations, such as return value from a method returning void.

Method Summary

Modifier and Type	Method and Description
Value	add(ParseSession session, Value that) Add or concatenate this value.
Value	and(ParseSession session, Value that) And this value.
LValue	asLValue(String operation) Verify that this instance is actually an LValue.
boolean	checkBoolean(ParseSession session, String operation) Evaluate this value, verify that it has boolean type, and return it.
int	checkIntegral(ParseSession session, String operation) Evaluate this value, verify that it has integral type (i.e., byte, char, short, or int), and return it.
Object	checkNotNull(ParseSession session, String operation) Evaluate this value, verify that it is not null, and return it.
Number	checkNumeric(ParseSession session, String operation) Evaluate this value, verify that it has numeric type (i.e., Number), and return it.
<T> T	checkType(ParseSession session, String operation, Class<T> type) Evaluate this value, verify that it has the expected type (or any sub-type), and return it.
Value	compare(ParseSession session, Value that, int mask) Ordered comparison to another value.
Value	divide(ParseSession session, Value that) Divide this value.
Object	get(ParseSession session) Evaluate this value within the given context.
Class<?>	getType(ParseSession session) Get the type of this value without evaluating it.
Value	invert(ParseSession session) Bitwise invert this value.
Value	lshift(ParseSession session, Value arg) Left shift this value.
Value	mod(ParseSession session, Value that) Modulo this value.
Value	multiply(ParseSession session, Value that) Multiply this value.
Value	negate(ParseSession session) Negate this value.
Value	or(ParseSession session, Value that) Or this value.
Value	rshift(ParseSession session, Value arg) Right shift this value.
Value	subtract(ParseSession session, Value that) Subtract this value.
Value	urshift(ParseSession session, Value arg) Unsigned right shift this value.
Value	xor(ParseSession session, Value that) Xor this value.
Value	xxcrement(ParseSession session, String operation, boolean increment) Increment/decrement this value.

Field Detail

LT

static final int LT

Flag mask value for use with compare().

See Also:

Constant Field Values

GT

static final int GT

Flag mask value for use with compare().

See Also:

Constant Field Values

EQ

static final int EQ

Flag mask value for use with compare().

See Also:

Constant Field Values

NO_VALUE

static final Value NO_VALUE

Special value that can be used to indicate "no value" in certain situations, such as return value from a method returning void. Actually evaluates to null.

Method Detail

get

Object get(ParseSession session)

Evaluate this value within the given context.

Normally this method should only be invoked once, and the result cached, because evaluation could have side effects.

Parameters:

session - parse session

Returns:

the evaluated result

getType

Class<?> getType(ParseSession session)

Get the type of this value without evaluating it.

This should perform a best-effort attempt to determine the type, but should not invoke get(). If the type is unknown, Object.class should be returned.

Parameters:

session - parse session

Returns:

the expected type of the evaluated result

checkNotNull

Object checkNotNull(ParseSession session,
                    String operation)

Evaluate this value, verify that it is not null, and return it.

Parameters:

session - current session

operation - description of operation for error messages

Returns:

the evaluated result

Throws:

EvalException - if this value is null

checkBoolean

boolean checkBoolean(ParseSession session,
                     String operation)

Evaluate this value, verify that it has boolean type, and return it.

Parameters:

session - current session

operation - description of operation for error messages

Returns:

the evaluated boolean value

Throws:

EvalException - if this value is not boolean

checkNumeric

Number checkNumeric(ParseSession session,
                    String operation)

Evaluate this value, verify that it has numeric type (i.e., Number), and return it.

Parameters:

session - current session

operation - description of operation for error messages

Returns:

the evaluated numeric value

Throws:

EvalException - if this value is not numeric

checkIntegral

int checkIntegral(ParseSession session,
                  String operation)

Evaluate this value, verify that it has integral type (i.e., byte, char, short, or int), and return it. Return its integer value.

Parameters:

session - current session

operation - description of operation for error messages

Returns:

the evaluated integer value

Throws:

EvalException - if this value is not integral

checkType

<T> T checkType(ParseSession session,
                String operation,
                Class<T> type)

Evaluate this value, verify that it has the expected type (or any sub-type), and return it. Return its value cast to that type.

Type Parameters:

T - expected type

Parameters:

session - current session

operation - description of operation for error messages

type - expected type

Returns:

the evaluated value cast to type

Throws:

EvalException - if this value does not have the expected type

xxcrement

Value xxcrement(ParseSession session,
                String operation,
                boolean increment)

Increment/decrement this value. Also supports BigInteger and BigDecimal. This value must be an LValue.

Parameters:

session - current session

operation - description of operation for error messages

increment - true to increment, false to decrement

Returns:

the adjusted value (which will not be an LValue)

Throws:

EvalException - if this value is not an LValue

EvalException - if this value is not numeric, BigInteger or BigDecimal

negate

Value negate(ParseSession session)

Negate this value.

Parameters:

session - current session

Returns:

negated result

Throws:

EvalException - if this value is not numeric

invert

Value invert(ParseSession session)

Bitwise invert this value.

Parameters:

session - current session

Returns:

inverted result

Throws:

EvalException - if this value is not numeric

multiply

Value multiply(ParseSession session,
               Value that)

Multiply this value.

Parameters:

session - current session

that - multiplicand

Returns:

multiplied result

Throws:

EvalException - if value(s) are not numeric

divide

Value divide(ParseSession session,
             Value that)

Divide this value.

Parameters:

session - current session

that - divisor

Returns:

divided result

Throws:

EvalException - if value(s) are not numeric

mod

Value mod(ParseSession session,
          Value that)

Modulo this value.

Parameters:

session - current session

that - divisor

Returns:

remaindered result

Throws:

EvalException - if value(s) are not numeric

add

Value add(ParseSession session,
          Value that)

Add or concatenate this value.

Parameters:

session - current session

that - addend

Returns:

added result

Throws:

EvalException - if value(s) are not numeric or String

subtract

Value subtract(ParseSession session,
               Value that)

Subtract this value. Also supports Set and NavigableSet difference.

Parameters:

session - current session

that - subtrahend

Returns:

subtracted result

Throws:

EvalException - if value(s) are not numeric or Set

lshift

Value lshift(ParseSession session,
             Value arg)

Left shift this value.

Parameters:

session - current session

arg - shift amount

Returns:

shifted result

Throws:

EvalException - if value(s) are not numeric

rshift

Value rshift(ParseSession session,
             Value arg)

Right shift this value.

Parameters:

session - current session

arg - shift amount

Returns:

shifted result

Throws:

EvalException - if value(s) are not numeric

urshift

Value urshift(ParseSession session,
              Value arg)

Unsigned right shift this value.

Parameters:

session - current session

arg - shift amount

Returns:

shifted result

Throws:

EvalException - if value(s) are not numeric

and

Value and(ParseSession session,
          Value that)

And this value. Also supports Set and NavigableSet intersection.

Parameters:

session - current session

that - and value

Returns:

and'ed result

Throws:

EvalException - if value(s) are not numeric, boolean, or Set

or

Value or(ParseSession session,
         Value that)

Or this value. Also supports Set and NavigableSet union.

Parameters:

session - current session

that - or value

Returns:

or'ed result

Throws:

EvalException - if value(s) are not numeric, boolean, or Set

xor

Value xor(ParseSession session,
          Value that)

Xor this value. Also supports Set and NavigableSet symmetric difference.

Parameters:

session - current session

that - xor value

Returns:

exclusive or'ed result

Throws:

EvalException - if value(s) are not numeric or boolean

compare

Value compare(ParseSession session,
              Value that,
              int mask)

Ordered comparison to another value. Supports numeric and Comparable comparison.

Parameters:

session - current session

that - value to compare to

mask - bit mask with bits LT, GT, and/or EQ

Returns:

boolean value which will be true if the comparison is true

Throws:

EvalException - if value(s) are not numeric or mutually Comparable

asLValue

LValue asLValue(String operation)

Verify that this instance is actually an LValue.

Parameters:

operation - description of operation for error messages

Returns:

this instance cast to LValue

Throws:

EvalException - if this instance is not an LValue