Package org.qdl_lang.expressions

Class ComparisonDyad

java.lang.Object

org.qdl_lang.expressions.ExpressionImpl

org.qdl_lang.expressions.Dyad

org.qdl_lang.expressions.ComparisonDyad

All Implemented Interfaces:

Serializable, ExpressionNode, ExpressionInterface, HasResultInterface, Statement

public class ComparisonDyad
extends Dyad

Dyad that compares the arguments, such as with comparisons, regex matching and types of equality.

Created by Jeff Gaynor
on 10/26/21 at 12:34 PM

See Also:

Serialized Form

Field Summary

Fields inherited from class org.qdl_lang.expressions.ExpressionImpl

arguments, result, valence

Fields inherited from interface org.qdl_lang.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
ComparisonDyad(int operatorType)
ComparisonDyad(int operatorType, ExpressionNode leftNode, ExpressionNode rightNode)
ComparisonDyad(int operatorType, TokenPosition tokenPosition)

Method Summary

Modifier and Type	Method	Description
Object	evaluate(State state)
protected ComparisonDyad	getLeftCD()
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.
protected Object	handleEquals(State state)	In this case, we have A == B or A != B.
protected boolean	isLeftArgCD()
protected boolean	isOpEquality()
protected ExpressionInterface	leftmostNode()
protected Object	newEvaluate(State state)

Methods inherited from class org.qdl_lang.expressions.Dyad

getLeftArgument, getRightArgument, isUnary, makeCopy, setLeftArgument, setRightArgument, setUnary

Methods inherited from class org.qdl_lang.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

ComparisonDyad

public ComparisonDyad(int operatorType,
                      TokenPosition tokenPosition)

ComparisonDyad

public ComparisonDyad(int operatorType)

ComparisonDyad

public ComparisonDyad(int operatorType,
                      ExpressionNode leftNode,
                      ExpressionNode rightNode)

Method Detail

evaluate

public Object evaluate(State state)

Specified by:

evaluate in interface Statement

Overrides:

evaluate in class Dyad

newEvaluate

protected Object newEvaluate(State state)

isLeftArgCD

protected boolean isLeftArgCD()

getLeftCD

protected ComparisonDyad getLeftCD()

isOpEquality

protected boolean isOpEquality()

handleEquals

protected Object handleEquals(State state)

In this case, we have A == B or A != B. Complications is that A or B may be comparison dyads. So there are 4 cases to handle

Parameters:

state -

Returns:

leftmostNode

protected ExpressionInterface leftmostNode()

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).

Specified by:

getNodeType in interface ExpressionInterface

Overrides:

getNodeType in class Dyad

Returns: