ConstantNode (QDL root module 1.5.6 API)

java.lang.Object
- edu.uiuc.ncsa.qdl.expressions.ExpressionImpl
- - edu.uiuc.ncsa.qdl.expressions.ConstantNode

All Implemented Interfaces:

ExpressionNode, ExpressionInterface, HasResultInterface, Statement, Serializable

Direct Known Subclasses:

AllIndices, QDLNull
```
public class ConstantNode
extends ExpressionImpl
```
Created by Jeff Gaynor
on 1/13/20 at 4:08 PM

See Also:

Serialized Form

Field Summary
- Fields inherited from class edu.uiuc.ncsa.qdl.expressions.ExpressionImpl
  arguments, result, valence
- Fields inherited from interface edu.uiuc.ncsa.qdl.statements.ExpressionInterface
  ALL_INDICES_NODE, ALT_IF_NODE, ASSIGNMENT_NODE, CLOSED_SLICE_NODE, COMPARISON_DYAD_NODE, CONSTANT_NODE, DYAD_NODE, DYADIC_FUNCTION_REFERENCE_NODE, EXPRESSION_STEM_NODE, EXPRESSION_STEM2_NODE, FUNCTION_REFERENCE_NODE, LAMBDA_DEFINITION_NODE, LIST_NODE, MODULE_NODE, MONAD_NODE, NILAD_NODE, OPEN_SLICE_NODE, PARENTHESIZED_NODE, PARSE_EXPRESSION_BLOCK_NODE, PARSE_STATEMENT_BLOCK_NODE, POLYAD_NODE, QDL_NULL_NODE, SELECT_NODE, SET_NODE, STEM_ENTRY_NODE, STEM_EXTRACTION_NODE, STEM_NODE, UNKNOWN_NODE, VARIABLE_NODE

Constructor Summary

Constructors
Constructor	Description
`ConstantNode(QDLNull result)`
`ConstantNode(Boolean result)`
`ConstantNode(Long result)`
`ConstantNode(Object result)`
`ConstantNode(Object result, int resultType)`
`ConstantNode(String result)`
`ConstantNode(BigDecimal result)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Object`	`evaluate(State state)`
`int`	`getNodeType()`	QDL is not strongly typed but Java is, so each node type should have a unique integer and conditionals should use that, not the instanceof operator.
`ExpressionNode`	`makeCopy()`

Methods inherited from class edu.uiuc.ncsa.qdl.expressions.ExpressionImpl
evalArg, evalLastArg, evaluatedArgs, getAlias, getArgAt, getArgCount, getArguments, getEvaluatedArgs, getLastArg, getOperatorType, getResult, getResultType, getSourceCode, getTokenPosition, hasAlias, hasEvaluatedArgs, hasTokenPosition, isEvaluated, isSizeQuery, setAlias, setArguments, setEvaluated, setEvaluatedArgs, setOperatorType, setResult, setResultType, setSizeQuery, setSourceCode, setTokenPosition, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - ConstantNode
```
public ConstantNode(String result)
```
  - ConstantNode
```
public ConstantNode(Long result)
```
  - ConstantNode
```
public ConstantNode(BigDecimal result)
```
  - ConstantNode
```
public ConstantNode(Boolean result)
```
  - ConstantNode
```
public ConstantNode(QDLNull result)
```
  - ConstantNode
```
public ConstantNode(Object result)
```
  - ConstantNode
```
public ConstantNode(Object result,
                    int resultType)
```
- Method Detail
  - evaluate
```
public Object evaluate(State state)
```
  - makeCopy
```
public ExpressionNode makeCopy()
```
  - getNodeType
```
public int getNodeType()
```
    Description copied from interface: ExpressionInterface
    
    QDL is not strongly typed but Java is, so each node type should have a unique integer and conditionals should use that, not the instanceof operator. This allows for efficient programming with switch statements rather than a bevy of conditionals (potentially each of which gets done even if the correct case has been handled).
    
    Returns: