RexSimplify (Flink : 1.16-SNAPSHOT API)

java.lang.Object
- org.apache.calcite.rex.RexSimplify

```
public class RexSimplify
extends Object
```
Context required to simplify a row-expression.
Copied to fix Calcite 1.26 bugs, should be removed for the next Calcite upgrade.
Changes (line numbers are from the original RexSimplify file):
1. CALCITE-4364 & FLINK-19811: Line 1307, Line 1764, Line 2638 ~ Line 2656.
2. CALCITE-4446 & FLINK-22015: Line 2542 ~ Line 2548, Line 2614 ~ Line 2619.

Field Summary

Fields
Modifier and Type Field and Description

org.apache.calcite.rex.RexBuilder rexBuilder

Fields
Modifier and Type	Field and Description
`org.apache.calcite.rex.RexBuilder`	`rexBuilder`

Constructor Summary

Constructors
Constructor and Description
`RexSimplify(org.apache.calcite.rex.RexBuilder rexBuilder, boolean unknownAsFalse, org.apache.calcite.rex.RexExecutor executor)` Deprecated.
`RexSimplify(org.apache.calcite.rex.RexBuilder rexBuilder, org.apache.calcite.plan.RelOptPredicateList predicates, boolean unknownAsFalse, org.apache.calcite.rex.RexExecutor executor)` Deprecated.
`RexSimplify(org.apache.calcite.rex.RexBuilder rexBuilder, org.apache.calcite.plan.RelOptPredicateList predicates, org.apache.calcite.rex.RexExecutor executor)` Creates a RexSimplify.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`org.apache.calcite.rex.RexNode`	`removeNullabilityCast(org.apache.calcite.rex.RexNode e)` Removes any casts that change nullability but not type.
`org.apache.calcite.rex.RexNode`	`simplify(org.apache.calcite.rex.RexNode e)` Simplifies a boolean expression.
`org.apache.calcite.rex.RexNode`	`simplifyAnd(org.apache.calcite.rex.RexCall e)` Deprecated.
`org.apache.calcite.rex.RexNode`	`simplifyAnds(Iterable<? extends org.apache.calcite.rex.RexNode> nodes)` Deprecated.
`org.apache.calcite.rex.RexNode`	`simplifyFilterPredicates(Iterable<? extends org.apache.calcite.rex.RexNode> predicates)` Combines predicates AND, optimizes, and returns null if the result is always false.
`org.apache.calcite.rex.RexNode`	`simplifyOr(org.apache.calcite.rex.RexCall call)` Deprecated.
`org.apache.calcite.rex.RexNode`	`simplifyOrs(List<org.apache.calcite.rex.RexNode> terms)` Deprecated.
`org.apache.calcite.rex.RexNode`	`simplifyPreservingType(org.apache.calcite.rex.RexNode e)` Simplifies a boolean expression, always preserving its type and its nullability.
`org.apache.calcite.rex.RexNode`	`simplifyPreservingType(org.apache.calcite.rex.RexNode e, org.apache.calcite.rex.RexUnknownAs unknownAs, boolean matchNullability)`
`org.apache.calcite.rex.RexNode`	`simplifyUnknownAs(org.apache.calcite.rex.RexNode e, org.apache.calcite.rex.RexUnknownAs unknownAs)` As `simplify(RexNode)`, but specifying how UNKNOWN values are to be treated.
`org.apache.calcite.rex.RexNode`	`simplifyUnknownAsFalse(org.apache.calcite.rex.RexNode e)` As `simplify(RexNode)`, but for a boolean expression for which a result of UNKNOWN will be treated as FALSE.
`RexSimplify`	`withParanoid(boolean paranoid)` Returns a RexSimplify the same as this but which verifies that the expression before and after simplification are equivalent.
`RexSimplify`	`withPredicates(org.apache.calcite.plan.RelOptPredicateList predicates)` Returns a RexSimplify the same as this but with a specified `predicates` value.
`RexSimplify`	`withUnknownAsFalse(boolean unknownAsFalse)` Deprecated. Use methods with a `RexUnknownAs` argument, such as `simplify(RexNode, RexUnknownAs)`.

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

- Field Detail
  - rexBuilder
```
public final org.apache.calcite.rex.RexBuilder rexBuilder
```
- Constructor Detail
  - RexSimplify
```
public RexSimplify(org.apache.calcite.rex.RexBuilder rexBuilder,
                   org.apache.calcite.plan.RelOptPredicateList predicates,
                   org.apache.calcite.rex.RexExecutor executor)
```
    Creates a RexSimplify.
    
    Parameters:
    
    rexBuilder - Rex builder
    
    predicates - Predicates known to hold on input fields
    
    executor - Executor for constant reduction, not null
  - RexSimplify
```
@Deprecated
public RexSimplify(org.apache.calcite.rex.RexBuilder rexBuilder,
                               boolean unknownAsFalse,
                               org.apache.calcite.rex.RexExecutor executor)
```
    Deprecated.
  - RexSimplify
```
@Deprecated
public RexSimplify(org.apache.calcite.rex.RexBuilder rexBuilder,
                               org.apache.calcite.plan.RelOptPredicateList predicates,
                               boolean unknownAsFalse,
                               org.apache.calcite.rex.RexExecutor executor)
```
    Deprecated.
- Method Detail
  - withUnknownAsFalse
```
@Deprecated
public RexSimplify withUnknownAsFalse(boolean unknownAsFalse)
```
    Deprecated. Use methods with a RexUnknownAs argument, such as simplify(RexNode, RexUnknownAs).
    
    Returns a RexSimplify the same as this but with a specified defaultUnknownAs value.
  - withPredicates
```
public RexSimplify withPredicates(org.apache.calcite.plan.RelOptPredicateList predicates)
```
    Returns a RexSimplify the same as this but with a specified predicates value.
  - withParanoid
```
public RexSimplify withParanoid(boolean paranoid)
```
    Returns a RexSimplify the same as this but which verifies that the expression before and after simplification are equivalent.
    
    See Also:
    
    verify(org.apache.calcite.rex.RexNode, org.apache.calcite.rex.RexNode, org.apache.calcite.rex.RexUnknownAs)
  - simplifyPreservingType
```
public org.apache.calcite.rex.RexNode simplifyPreservingType(org.apache.calcite.rex.RexNode e)
```
    Simplifies a boolean expression, always preserving its type and its nullability.
    This is useful if you are simplifying expressions in a Project.
  - simplifyPreservingType
```
public org.apache.calcite.rex.RexNode simplifyPreservingType(org.apache.calcite.rex.RexNode e,
                                                             org.apache.calcite.rex.RexUnknownAs unknownAs,
                                                             boolean matchNullability)
```
  - simplify
```
public org.apache.calcite.rex.RexNode simplify(org.apache.calcite.rex.RexNode e)
```
    Simplifies a boolean expression.
    In particular:
    - simplify(x = 1 AND y = 2 AND NOT x = 1) returns y = 2
    - simplify(x = 1 AND FALSE) returns FALSE
    Handles UNKNOWN values using the policy specified when you created this RexSimplify. Unless you used a deprecated constructor, that policy is RexUnknownAs.UNKNOWN.
    If the expression is a predicate in a WHERE clause, consider instead using simplifyUnknownAsFalse(RexNode).
    Parameters:
    
    e - Expression to simplify
  - simplifyUnknownAsFalse
```
public final org.apache.calcite.rex.RexNode simplifyUnknownAsFalse(org.apache.calcite.rex.RexNode e)
```
    As simplify(RexNode), but for a boolean expression for which a result of UNKNOWN will be treated as FALSE.
    Use this form for expressions on a WHERE, ON, HAVING or FILTER(WHERE) clause.
    This may allow certain additional simplifications. A result of UNKNOWN may yield FALSE, however it may still yield UNKNOWN. (If the simplified expression has type BOOLEAN NOT NULL, then of course it can only return FALSE.)
  - simplifyUnknownAs
```
public org.apache.calcite.rex.RexNode simplifyUnknownAs(org.apache.calcite.rex.RexNode e,
                                                        org.apache.calcite.rex.RexUnknownAs unknownAs)
```
    As simplify(RexNode), but specifying how UNKNOWN values are to be treated.
    If UNKNOWN is treated as FALSE, this may allow certain additional simplifications. A result of UNKNOWN may yield FALSE, however it may still yield UNKNOWN. (If the simplified expression has type BOOLEAN NOT NULL, then of course it can only return FALSE.)
  - simplifyAnds
```
@Deprecated
public org.apache.calcite.rex.RexNode simplifyAnds(Iterable<? extends org.apache.calcite.rex.RexNode> nodes)
```
    Deprecated.
    
    Simplifies a conjunction of boolean expressions.
  - simplifyAnd
```
@Deprecated
public org.apache.calcite.rex.RexNode simplifyAnd(org.apache.calcite.rex.RexCall e)
```
    Deprecated.
  - simplifyOr
```
@Deprecated
public org.apache.calcite.rex.RexNode simplifyOr(org.apache.calcite.rex.RexCall call)
```
    Deprecated.
    
    Simplifies OR(x, x) into x, and similar. The simplified expression returns UNKNOWN values as is (not as FALSE).
  - simplifyOrs
```
@Deprecated
public org.apache.calcite.rex.RexNode simplifyOrs(List<org.apache.calcite.rex.RexNode> terms)
```
    Deprecated.
    
    Simplifies a list of terms and combines them into an OR. Modifies the list in place. The simplified expression returns UNKNOWN values as is (not as FALSE).
  - removeNullabilityCast
```
public org.apache.calcite.rex.RexNode removeNullabilityCast(org.apache.calcite.rex.RexNode e)
```
    Removes any casts that change nullability but not type.
    For example, CAST(1 = 0 AS BOOLEAN) becomes 1 = 0.
  - simplifyFilterPredicates
```
public org.apache.calcite.rex.RexNode simplifyFilterPredicates(Iterable<? extends org.apache.calcite.rex.RexNode> predicates)
```
    Combines predicates AND, optimizes, and returns null if the result is always false.
    The expression is simplified on the assumption that an UNKNOWN value is always treated as FALSE. Therefore the simplified expression may sometimes evaluate to FALSE where the original expression would evaluate to UNKNOWN.
    
    Parameters:
    
    predicates - Filter condition predicates
    
    Returns:
    
    simplified conjunction of predicates for the filter, null if always false

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Class RexSimplify

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

rexBuilder

Constructor Detail

RexSimplify

RexSimplify

RexSimplify

Method Detail

withUnknownAsFalse

withPredicates

withParanoid

simplifyPreservingType

simplifyPreservingType

simplify

simplifyUnknownAsFalse

simplifyUnknownAs

simplifyAnds

simplifyAnd

simplifyOr

simplifyOrs

removeNullabilityCast

simplifyFilterPredicates

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