Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.sql.compile.ParameterNode

Modifier and Type	Field and Description
private DataValueDescriptor	defaultValue
private JSQLType	jsqlType This ParameterNode may turn up as an argument to a replicated Work Unit.
private int	orderableVariantType
private int	parameterNumber
private ValueNode	returnOutputParameter By default, we assume we are just a normal, harmless little ole parameter.
private DataTypeDescriptor[]	userParameterTypes Pointer to the array in the CompilerContext that holds array of types for all the user-visible paramerers..
private ValueNode	valToGenerate If this parameter node was created as part of a "probe predicate" for an InListOperatorNode then it does not actually correspond to a specific value--we just created it as a start-key place-holder for IN-list values at execution time.

Access	Constructor and Description
pack-priv	ParameterNode(int The number of this parameter, (unique per query starting at 0) parameterNumber, DataValueDescriptor The default value for this parameter defaultValue, ContextManager The context manager cm) Constructor for a ParameterNode.

Method Summary

Modifier and Type	Method and Description
pack-priv ValueNode	Returns: The new top of the expression tree. bindExpression(FromList The FROM list for the query this expression is in, for binding columns. fromList, SubqueryList The subquery list being built as we find SubqueryNodes subqueryList, List<AggregateNode> The aggregate list being built as we find AggregateNodes aggregates) Overrides org.apache.derby.impl.sql.compile.ValueNode.bindExpression. Bind this expression.
pack-priv boolean	constantExpression(PredicateList whereClause) Overrides org.apache.derby.impl.sql.compile.ValueNode.constantExpression. Return whether or not this expression tree represents a constant value.
pack-priv void	generateExpression(ExpressionClassBuilder The ExpressionClassBuilder for the class being built acb, MethodBuilder The method the expression will go into mb) Overrides org.apache.derby.impl.sql.compile.ValueNode.generateExpression. For a ParameterNode, we generate for the return value: (<java type name>) ( (BaseActivation) this.getParameter(parameterNumber) )
pack-priv static void	generateParameterValueSet(ExpressionClassBuilder The ExpressionClassBuilder for the class we're building acb, int number of parameters for this statement numberOfParameters, List<ParameterNode> The parameter list for the statement. parameterList) Generate the code to create the ParameterValueSet, if necessary, when constructing the activation.
pack-priv DataValueDescriptor	Returns: the value, may be null getDefaultValue() Get the default value for the parameter.
public JSQLType	Returns: the JSQLType that the remote system assigned getJSQLType() Get the JSQLType associated with this parameter.
protected int	Returns: The variant type for the underlying expression. getOrderableVariantType() Overrides org.apache.derby.impl.sql.compile.ValueNode.getOrderableVariantType. Return the variant type for the underlying expression.
pack-priv int	Returns: The parameter number getParameterNumber() Get the parameter number
pack-priv TypeId	getTypeId() Overrides org.apache.derby.impl.sql.compile.ValueNode.getTypeId. Get the TypeId from this ValueNode.
pack-priv boolean	Returns: Whether or not this expression tree represents a constant expression. isConstantExpression() Overrides org.apache.derby.impl.sql.compile.ValueNode.isConstantExpression. Return whether or not this expression tree represents a constant expression.
pack-priv boolean	isEquivalent(ValueNode the node to compare this ValueNode against. o) Implements abstract org.apache.derby.impl.sql.compile.ValueNode.isEquivalent. Tests if this node is equivalent to the specified ValueNode.
pack-priv boolean	isParameterNode() Overrides org.apache.derby.impl.sql.compile.ValueNode.isParameterNode. Returns TRUE if this is a parameter node.
pack-priv boolean	Returns: true if it is a return param isReturnOutputParam() Is this as a return output parameter (e.g. ?
pack-priv boolean	requiresTypeFromContext() Overrides org.apache.derby.impl.sql.compile.ValueNode.requiresTypeFromContext. Returns TRUE if the type of this node will be determined from the context in which it is getting used.
pack-priv void	setDescriptors(DataTypeDescriptor[] The array of DataTypeServices to fill in when the parameters are bound. descriptors) Set the descriptor array
public void	setJSQLType(JSQLType the JSQLType associated with this parameter type) Set the JSQLType of this parameter.
pack-priv void	setOrderableVariantType(int type) In a special circumstance, we want to consider parameters as constants.
pack-priv void	setReturnOutputParam(ValueNode valueNode) Mark this as a return output parameter (e.g. ?
pack-priv void	setType(DataTypeDescriptor The DataTypeServices to set for this parameter descriptor) Overrides org.apache.derby.impl.sql.compile.ValueNode.setType. Set the DataTypeServices for this parameter
protected void	setValueToGenerate(ValueNode The ValueNode to generate in place of this ParameterNode. vn) Save the received ValueNode locally so that we can generate it (in place of "this") at generation time.

Inherited from org.apache.derby.impl.sql.compile.ValueNode:: bindExpression categorize changeToCNF checkIsBoolean checkTopPredicatesForEqualsConditions copyFields eliminateNots evaluateConstantExpressions genEqualsFalseTree generate genIsNullTree genSQLJavaSQLTree getClone getColumnName getConstantValueAsObject getDataValueFactory getSchemaName getSourceResultColumn getTableName getTablesReferenced getTransformed getTypeCompiler getTypeServices isBinaryEqualsOperatorNode isBooleanFalse isBooleanTrue isCloneable isInListProbeNode isRelationalOperator isSameNodeKind optimizableEqualityNode preprocess putAndsOnTop remapColumnReferencesToExpressions selectivity setCollationInfo setCollationInfo setCollationUsingCompilationSchema setCollationUsingCompilationSchema setNullability setTransformed setType setType toString updatableByCursor verifyChangeToCNF verifyEliminateNots verifyPutAndsOnTop

defaultValue	back to summary
private DataValueDescriptor defaultValue

jsqlType	back to summary
private JSQLType jsqlType This ParameterNode may turn up as an argument to a replicated Work Unit. If so, the remote system will have figured out the type of this node. That's what this variable is for.

orderableVariantType	back to summary
private int orderableVariantType

parameterNumber	back to summary
private int parameterNumber

returnOutputParameter	back to summary
private ValueNode returnOutputParameter By default, we assume we are just a normal, harmless little ole parameter. But sometimes we may be a return parameter (e.g. ? = CALL myMethod()).

userParameterTypes	back to summary
private DataTypeDescriptor[] userParameterTypes Pointer to the array in the CompilerContext that holds array of types for all the user-visible paramerers.. When each parameter is bound, it fills in its type descriptor in this array. Note that the array is allocated in the parser, but the individual elements are not filled in until their corresponding parameters are bound. This array is not read in this class, but is read from the CompilerContext on completion of compiling the statement. In some case a parameter node may exist but is not a visble user parameter, in this case typeServices will be null so that setting its type will not modify the user's set.

valToGenerate	back to summary
private ValueNode valToGenerate If this parameter node was created as part of a "probe predicate" for an InListOperatorNode then it does not actually correspond to a specific value--we just created it as a start-key place-holder for IN-list values at execution time. In order to serve that purpose we need to generate some value that can be used as the place-holder. Since this parameter node is "fake" and does not correspond to an actual parameter, we can't really generate it; so the following field holds some legitimate ValueNode--either a constant node or a "real" parameter node--that we can generate to serve as the place-holder.

ParameterNode	back to summary
pack-priv ParameterNode(int parameterNumber, DataValueDescriptor defaultValue, ContextManager cm) Constructor for a ParameterNode. Parameters parameterNumber:int The number of this parameter, (unique per query starting at 0) defaultValue:DataValueDescriptor The default value for this parameter cm:ContextManager The context manager

Method Detail

bindExpression	back to summary
pack-priv ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, List<AggregateNode> aggregates) throws StandardException Overrides org.apache.derby.impl.sql.compile.ValueNode.bindExpression. Bind this expression. A parameter can't figure out what its type is without knowing where it appears, so this method does nothing. It is up to the node that points to this parameter node to figure out the type of the parameter and set it, using the setType() method above. Parameters fromList:FromList The FROM list for the query this expression is in, for binding columns. subqueryList:SubqueryList The subquery list being built as we find SubqueryNodes aggregates:List<AggregateNode> The aggregate list being built as we find AggregateNodes Returns:ValueNode The new top of the expression tree. Annotations @Override Exceptions StandardException: Thrown on error

bindExpression

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pack-priv ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, List<AggregateNode> aggregates) throws StandardException

Overrides org.apache.derby.impl.sql.compile.ValueNode.bindExpression.

Bind this expression. A parameter can't figure out what its type is without knowing where it appears, so this method does nothing. It is up to the node that points to this parameter node to figure out the type of the parameter and set it, using the setType() method above.

Parameters

fromList:FromList: The FROM list for the query this expression is in, for binding columns.
subqueryList:SubqueryList: The subquery list being built as we find SubqueryNodes
aggregates:List<AggregateNode>: The aggregate list being built as we find AggregateNodes

Returns:ValueNode

The new top of the expression tree.

Annotations

@Override

Exceptions

StandardException:: Thrown on error

constantExpression back to summary

constantExpression	back to summary
pack-priv boolean constantExpression(PredicateList whereClause) Overrides org.apache.derby.impl.sql.compile.ValueNode.constantExpression. Doc from org.apache.derby.impl.sql.compile.ValueNode.constantExpression. Return whether or not this expression tree represents a constant value. In this case, "constant" means that it will always evaluate to the same thing, even if it includes columns. A column is constant if it is compared to a constant expression. Returns:boolean True means this expression tree represents a constant value. Annotations @Override See Also `ValueNode#constantExpression`

pack-priv boolean constantExpression(PredicateList whereClause)

Overrides org.apache.derby.impl.sql.compile.ValueNode.constantExpression.

Doc from org.apache.derby.impl.sql.compile.ValueNode.constantExpression.

Return whether or not this expression tree represents a constant value. In this case, "constant" means that it will always evaluate to the same thing, even if it includes columns. A column is constant if it is compared to a constant expression.

Returns:boolean

True means this expression tree represents a constant value.

Annotations

@Override

See Also

ValueNode#constantExpression

generateExpression	back to summary
pack-priv void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException Overrides org.apache.derby.impl.sql.compile.ValueNode.generateExpression. For a ParameterNode, we generate for the return value: () ( (BaseActivation) this.getParameter(parameterNumber) ) Parameters acb:ExpressionClassBuilder The ExpressionClassBuilder for the class being built mb:MethodBuilder The method the expression will go into Annotations @Override Exceptions StandardException: Thrown on error

generateExpression

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pack-priv void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException

Overrides org.apache.derby.impl.sql.compile.ValueNode.generateExpression.

For a ParameterNode, we generate for the return value: () ( (BaseActivation) this.getParameter(parameterNumber) )

Parameters

acb:ExpressionClassBuilder: The ExpressionClassBuilder for the class being built
mb:MethodBuilder: The method the expression will go into

Annotations

@Override

Exceptions

StandardException:: Thrown on error

generateParameterValueSet	back to summary
pack-priv static void generateParameterValueSet(ExpressionClassBuilder acb, int numberOfParameters, List<ParameterNode> parameterList) throws StandardException Generate the code to create the ParameterValueSet, if necessary, when constructing the activation. Also generate the code to call a method that will throw an exception if we try to execute without all the parameters being set. This generated code goes into the Activation's constructor early on. Parameters acb:ExpressionClassBuilder The ExpressionClassBuilder for the class we're building numberOfParameters:int number of parameters for this statement parameterList:List<ParameterNode> The parameter list for the statement. Exceptions StandardException: on error

generateParameterValueSet

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pack-priv static void generateParameterValueSet(ExpressionClassBuilder acb, int numberOfParameters, List<ParameterNode> parameterList) throws StandardException

Generate the code to create the ParameterValueSet, if necessary, when constructing the activation. Also generate the code to call a method that will throw an exception if we try to execute without all the parameters being set. This generated code goes into the Activation's constructor early on.

Parameters

acb:ExpressionClassBuilder: The ExpressionClassBuilder for the class we're building
numberOfParameters:int: number of parameters for this statement
parameterList:List<ParameterNode>: The parameter list for the statement.

Exceptions

StandardException:: on error

getDefaultValue	back to summary
pack-priv DataValueDescriptor getDefaultValue() Get the default value for the parameter. Parameters may get default values for optimization purposes. Returns:DataValueDescriptor the value, may be null

getDefaultValue

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pack-priv DataValueDescriptor getDefaultValue()

Get the default value for the parameter. Parameters may get default values for optimization purposes.

Returns:DataValueDescriptor: the value, may be null

getJSQLType	back to summary
public JSQLType getJSQLType() Get the JSQLType associated with this parameter. Again, part of method resolution for replicated work units. Returns:JSQLType the JSQLType that the remote system assigned

getJSQLType

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public JSQLType getJSQLType()

Get the JSQLType associated with this parameter. Again, part of method resolution for replicated work units.

Returns:JSQLType: the JSQLType that the remote system assigned

getOrderableVariantType	back to summary
protected int getOrderableVariantType() Overrides org.apache.derby.impl.sql.compile.ValueNode.getOrderableVariantType. Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions) Returns:int The variant type for the underlying expression. Annotations @Override

getOrderableVariantType

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protected int getOrderableVariantType()

Overrides org.apache.derby.impl.sql.compile.ValueNode.getOrderableVariantType.

Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions)

Returns:int

The variant type for the underlying expression.

Annotations

@Override

getParameterNumber	back to summary
pack-priv int getParameterNumber() Get the parameter number Returns:int The parameter number

getParameterNumber

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pack-priv int getParameterNumber()

Get the parameter number

Returns:int: The parameter number

getTypeId	back to summary
pack-priv TypeId getTypeId() throws StandardException Overrides org.apache.derby.impl.sql.compile.ValueNode.getTypeId. Doc from org.apache.derby.impl.sql.compile.ValueNode.getTypeId. Get the TypeId from this ValueNode. Returns:TypeId The TypeId from this ValueNode. This may be null if the node isn't bound yet. Annotations @Override

getTypeId

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pack-priv TypeId getTypeId() throws StandardException

Overrides org.apache.derby.impl.sql.compile.ValueNode.getTypeId.

Doc from org.apache.derby.impl.sql.compile.ValueNode.getTypeId.

Get the TypeId from this ValueNode.

Returns:TypeId

The TypeId from this ValueNode. This may be null if the node isn't bound yet.

Annotations

@Override

isConstantExpression	back to summary
pack-priv boolean isConstantExpression() Overrides org.apache.derby.impl.sql.compile.ValueNode.isConstantExpression. Return whether or not this expression tree represents a constant expression. Returns:boolean Whether or not this expression tree represents a constant expression. Annotations @Override

isConstantExpression

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pack-priv boolean isConstantExpression()

Overrides org.apache.derby.impl.sql.compile.ValueNode.isConstantExpression.

Return whether or not this expression tree represents a constant expression.

Returns:boolean

Whether or not this expression tree represents a constant expression.

Annotations

@Override

isEquivalent back to summary

isEquivalent	back to summary
pack-priv boolean isEquivalent(ValueNode o) Implements abstract org.apache.derby.impl.sql.compile.ValueNode.isEquivalent. Doc from org.apache.derby.impl.sql.compile.ValueNode.isEquivalent. Tests if this node is equivalent to the specified ValueNode. Two ValueNodes are considered equivalent if they will evaluate to the same value during query execution. This method provides basic expression matching facility for the derived class of ValueNode and it is used by the language layer to compare the node structural form of the two expressions for equivalence at bind phase. Note that it is not comparing the actual row values at runtime to produce a result; hence, when comparing SQL NULLs, they are considered to be equivalent and not unknown. One usage case of this method in this context is to compare the select column expression against the group by expression to check if they are equivalent. e.g.: SELECT c1+c2 FROM t1 GROUP BY c1+c2 In general, node equivalence is determined by the derived class of ValueNode. But they generally abide to the rules below: The two ValueNodes must be of the same node type to be considered equivalent. e.g.: CastNode vs. CastNode - equivalent (if their args also match), ColumnReference vs CastNode - not equivalent. If node P contains other ValueNode(s) and so on, those node(s) must also be of the same node type to be considered equivalent. If node P takes a parameter list, then the number of arguments and its arguments for the two nodes must also match to be considered equivalent. e.g.: CAST(c1 as INTEGER) vs CAST(c1 as SMALLINT), they are not equivalent. When comparing SQL NULLs in this context, they are considered to be equivalent. If this does not apply or it is determined that the two nodes are not equivalent then the derived class of this method should return false; otherwise, return true. Parameters o:ValueNode the node to compare this ValueNode against. Returns:boolean `true` if the two nodes are equivalent, `false` otherwise.

pack-priv boolean isEquivalent(ValueNode o)

Implements abstract org.apache.derby.impl.sql.compile.ValueNode.isEquivalent.

Doc from org.apache.derby.impl.sql.compile.ValueNode.isEquivalent.

Tests if this node is equivalent to the specified ValueNode. Two ValueNodes are considered equivalent if they will evaluate to the same value during query execution.

This method provides basic expression matching facility for the derived class of ValueNode and it is used by the language layer to compare the node structural form of the two expressions for equivalence at bind phase.

Note that it is not comparing the actual row values at runtime to produce a result; hence, when comparing SQL NULLs, they are considered to be equivalent and not unknown.

One usage case of this method in this context is to compare the select column expression against the group by expression to check if they are equivalent. e.g.:

SELECT c1+c2 FROM t1 GROUP BY c1+c2

In general, node equivalence is determined by the derived class of ValueNode. But they generally abide to the rules below:

The two ValueNodes must be of the same node type to be considered equivalent. e.g.: CastNode vs. CastNode - equivalent (if their args also match), ColumnReference vs CastNode - not equivalent.
If node P contains other ValueNode(s) and so on, those node(s) must also be of the same node type to be considered equivalent.
If node P takes a parameter list, then the number of arguments and its arguments for the two nodes must also match to be considered equivalent. e.g.: CAST(c1 as INTEGER) vs CAST(c1 as SMALLINT), they are not equivalent.
When comparing SQL NULLs in this context, they are considered to be equivalent.
If this does not apply or it is determined that the two nodes are not equivalent then the derived class of this method should return false; otherwise, return true.

Parameters

o:ValueNode: the node to compare this ValueNode against.

Returns:boolean

true if the two nodes are equivalent, false otherwise.

isParameterNode back to summary

isParameterNode	back to summary
pack-priv boolean isParameterNode() Overrides org.apache.derby.impl.sql.compile.ValueNode.isParameterNode. Doc from org.apache.derby.impl.sql.compile.ValueNode.isParameterNode. Returns TRUE if this is a parameter node. We do lots of special things with Parameter Nodes. Annotations @Override See Also `ValueNode#isParameterNode`

pack-priv boolean isParameterNode()

Overrides org.apache.derby.impl.sql.compile.ValueNode.isParameterNode.

Doc from org.apache.derby.impl.sql.compile.ValueNode.isParameterNode.

Returns TRUE if this is a parameter node. We do lots of special things with Parameter Nodes.

Annotations

@Override

See Also

ValueNode#isParameterNode

isReturnOutputParam	back to summary
pack-priv boolean isReturnOutputParam() Is this as a return output parameter (e.g. ? = CALL myMethod()) Returns:boolean true if it is a return param

isReturnOutputParam

back to summary

pack-priv boolean isReturnOutputParam()

Is this as a return output parameter (e.g. ? = CALL myMethod())

Returns:boolean: true if it is a return param

requiresTypeFromContext back to summary

requiresTypeFromContext	back to summary
pack-priv boolean requiresTypeFromContext() Overrides org.apache.derby.impl.sql.compile.ValueNode.requiresTypeFromContext. Doc from org.apache.derby.impl.sql.compile.ValueNode.requiresTypeFromContext. Returns TRUE if the type of this node will be determined from the context in which it is getting used. If true is returned then after bindExpression() is called on the node, its type must be set (from the relevant context) using setType(). Returns:boolean Whether this node's type will be determined from the context Annotations @Override See Also `ValueNode#requiresTypeFromContext`

pack-priv boolean requiresTypeFromContext()

Overrides org.apache.derby.impl.sql.compile.ValueNode.requiresTypeFromContext.

Doc from org.apache.derby.impl.sql.compile.ValueNode.requiresTypeFromContext.

Returns TRUE if the type of this node will be determined from the context in which it is getting used. If true is returned then after bindExpression() is called on the node, its type must be set (from the relevant context) using setType().

Returns:boolean

Whether this node's type will be determined from the context

Annotations

@Override

See Also

ValueNode#requiresTypeFromContext

setDescriptors	back to summary
pack-priv void setDescriptors(DataTypeDescriptor[] descriptors) Set the descriptor array Parameters descriptors:DataTypeDescriptor[] The array of DataTypeServices to fill in when the parameters are bound.

setDescriptors

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pack-priv void setDescriptors(DataTypeDescriptor[] descriptors)

Set the descriptor array

Parameters

descriptors:DataTypeDescriptor[]: The array of DataTypeServices to fill in when the parameters are bound.

setJSQLType	back to summary
public void setJSQLType(JSQLType type) Set the JSQLType of this parameter. This supports the unnamed parameters that we use for replicated work units. Parameters type:JSQLType the JSQLType associated with this parameter

setJSQLType

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public void setJSQLType(JSQLType type)

Set the JSQLType of this parameter. This supports the unnamed parameters that we use for replicated work units.

Parameters

type:JSQLType: the JSQLType associated with this parameter

setOrderableVariantType	back to summary
pack-priv void setOrderableVariantType(int type) In a special circumstance, we want to consider parameters as constants. For that situation, we allow a caller to temporarily set us to CONSTANT and then restore us.

setReturnOutputParam	back to summary
pack-priv void setReturnOutputParam(ValueNode valueNode) Mark this as a return output parameter (e.g. ? = CALL myMethod())

setType	back to summary
pack-priv void setType(DataTypeDescriptor descriptor) throws StandardException Overrides org.apache.derby.impl.sql.compile.ValueNode.setType. Set the DataTypeServices for this parameter Parameters descriptor:DataTypeDescriptor The DataTypeServices to set for this parameter Annotations @Override

setType

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pack-priv void setType(DataTypeDescriptor descriptor) throws StandardException

Overrides org.apache.derby.impl.sql.compile.ValueNode.setType.

Set the DataTypeServices for this parameter

Parameters

descriptor:DataTypeDescriptor: The DataTypeServices to set for this parameter

Annotations

@Override

setValueToGenerate	back to summary
protected void setValueToGenerate(ValueNode vn) Save the received ValueNode locally so that we can generate it (in place of "this") at generation time. See the preprocess() method of InListOperatorNode for more on how this is used. Parameters vn:ValueNode The ValueNode to generate in place of this ParameterNode.

setValueToGenerate

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protected void setValueToGenerate(ValueNode vn)

Save the received ValueNode locally so that we can generate it (in place of "this") at generation time. See the preprocess() method of InListOperatorNode for more on how this is used.

Parameters

vn:ValueNode: The ValueNode to generate in place of this ParameterNode.

public Class ParameterNode

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