Package org.qdl_lang.variables.values

Class QDLKey

java.lang.Object

org.qdl_lang.variables.values.QDLValue

org.qdl_lang.variables.values.QDLKey

All Implemented Interfaces:

Serializable, Comparable<QDLValue>, Constants

Direct Known Subclasses:

LongValue, StemValue, StringValue

public class QDLKey
extends QDLValue

A marker class for those QDLValues that may also function as keys to stems and lists.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.qdl_lang.variables.values.QDLValue

axisValue, booleanValue, decimalValue, dyadicFunctionValue, functionValue, longValue, moduleValue, nullValue, setValue, stemValue, stringValue

Fields inherited from interface org.qdl_lang.variables.Constants

ALL_INDICES_NAME, ALL_INDICES_TYPE, ARG_COUNT_TYPE, AXIS_RESTRICTION_NAME, AXIS_RESTRICTION_TYPE, BOOLEAN_NAME, BOOLEAN_TYPE, DECIMAL_NAME, DECIMAL_TYPE, DYADIC_FUNCTION_NAME, DYADIC_FUNCTION_TYPE, FUNCTION_NAME, FUNCTION_TYPE, INTEGER_TYPE, LIST_NAME, LIST_TYPE, LONG_NAME, LONG_TYPE, MODULE_NAME, MODULE_TYPE, NULL_NAME, NULL_TYPE, SET_NAME, SET_TYPE, STEM_NAME, STEM_TYPE, STRING_NAME, STRING_TYPE, UNKNOWN_NAME, UNKNOWN_TYPE

Constructor Summary

Constructors

Constructor	Description
QDLKey(Object value)

Method Summary

Modifier and Type	Method	Description
protected static LongValue	decimalToLong(BigDecimal decimal)	Decimals may be used as keys if they have a trivial fractional part.
static QDLKey	from(Object value)	This will convert the POJO to a key.
static Collection<QDLKey>	from(Collection<Object> values)	Converts a collection -- a list or set -- of objects to keys.

Methods inherited from class org.qdl_lang.variables.values.QDLValue

asAxisExpression, asBoolean, asDecimal, asDyadicFunction, asFunction, asJavaValue, asLong, asModule, asNull, asQDLValue, asSet, asStem, asString, castToJavaValues, castToJavaValues, castToQDLValueList, castToQDLValues, castToQDLValues, castToQDLValues, castToQDLValues, compareTo, equals, getInputForm, getNullValue, getType, getValue, hashCode, hasValue, isAllIndices, isAxisRestriction, isBoolean, isDecimal, isDyadicFunction, isFunction, isList, isListOrStem, isLong, isModule, isNull, isScalar, isSet, isStem, isString, setValue, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

QDLKey

public QDLKey(Object value)

Method Detail

from

public static QDLKey from(Object value)

This will convert the POJO to a key. It does try to return the correct actual type so feeding in a string like "2" will result in a LongValue of 2. By the same token, decimal values are checked to see if they are actually integers

Parameters:

value -

Returns:

decimalToLong

protected static LongValue decimalToLong(BigDecimal decimal)

Decimals may be used as keys if they have a trivial fractional part. Since an expression like

     a := 6.0/3.0;
 

would reliably yield the value 2.0, This should be usable as a stem index as the integer 2.

Parameters:

decimal -

Returns:

from

public static Collection<QDLKey> from(Collection<Object> values)

Converts a collection -- a list or set -- of objects to keys. Note that non-key values will cause an error.

Parameters:

values -

Returns: