Package org.qdl_lang.expressions

Class ESN2

java.lang.Object

org.qdl_lang.expressions.ExpressionImpl

org.qdl_lang.expressions.ESN2

All Implemented Interfaces:

Serializable, ExpressionNode, ExpressionInterface, HasResultInterface, Statement

public class ESN2
extends ExpressionImpl

After a parser change to treat the dot as an operator, this was introduced. It mostly has replaced the older ExpressionStemNode, but not quite everywhere yet.

Created by Jeff Gaynor
on 6/12/21 at 6:42 AM

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, AXIS_RESTRICTION_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
ESN2()

Method Summary

Modifier and Type	Method	Description
protected void	computeNullity(IndexList indexList)	Actual stem contract: Evaluates the indices from right to left and does the evaluations, Nullity refers to how many of the indices "go away" on actual evaluation.
QDLValue	evaluate(State state)
protected QDLValue	get(State state)
QDLValue	getDefaultValue()
ExpressionInterface	getLeftArg()
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.
ExpressionInterface	getRightArg()
boolean	isDefaultValueNode()
ExpressionInterface	makeCopy()
boolean	remove(State state)
void	set(State state, QDLValue newValue)
void	setDefaultValue(QDLValue defaultValue)
void	setDefaultValueNode(boolean defaultValueNode)
void	setLeftArg(ExpressionInterface swri)
void	setRightArg(ExpressionInterface swri)

Methods inherited from class org.qdl_lang.expressions.ExpressionImpl

addArgument, 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, setResult, setSizeQuery, setSourceCode, setTokenPosition, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ESN2

public ESN2()

Method Detail

evaluate

public QDLValue evaluate(State state)

isDefaultValueNode

public boolean isDefaultValueNode()

setDefaultValueNode

public void setDefaultValueNode(boolean defaultValueNode)

makeCopy

public ExpressionInterface makeCopy()

getLeftArg

public ExpressionInterface getLeftArg()

setLeftArg

public void setLeftArg(ExpressionInterface swri)

setRightArg

public void setRightArg(ExpressionInterface swri)

getRightArg

public ExpressionInterface getRightArg()

getDefaultValue

public QDLValue getDefaultValue()

setDefaultValue

public void setDefaultValue(QDLValue defaultValue)

get

protected QDLValue get(State state)

computeNullity

protected void computeNullity(IndexList indexList)

Actual stem contract: Evaluates the indices from right to left and does the evaluations, Nullity refers to how many of the indices "go away" on actual evaluation. When this is done, the index set is simply indices, ready for set or get in the stem:

     rank(stem) + nullity(stem) == dim(stem)
 

for a given index. So if we have

     x.1.2 := 5; p := 1; q := 2;
 

Computing

     w.x.p.q
       |---|  = dim is 3
         => x.1.2 = 5
              |-|
                + - nullity is 2, since these 2 go away
     = w.5
         |
         +- rank is 1
 

hence

     rank + nullity = dim
       1  +   2     =  3
 

Parameters:

indexList -

remove

public boolean remove(State state)

set

public void set(State state,
                QDLValue newValue)

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: