Module com.darkcollective.relix.ast

Package com.darkcollective.relix.ast.visitor.internal

Class PrettyPrinter

java.lang.Object

com.darkcollective.relix.ast.visitor.internal.PrettyPrinter

All Implemented Interfaces:

RelNodeVisitor<String>

public final class PrettyPrinter
extends Object
implements RelNodeVisitor<String>

Serialises a RelNode tree to a Unicode relational algebra string.

The output uses standard relational algebra symbols (π σ ρ ⋈ ⨝ ⟕ ⟖ ⟗ ⋉ ▷ × ∪ ⊎ − ∩ ÷ ∆ ∘ ∀ γ τ λ δ ω) and is designed to round-trip through the relix-parser module.

Predicate and operand formatting is delegated to PredicatePrettyPrinter and OperandPrettyPrinter respectively.

Instances are stateless and safe for concurrent use.

See Also:

• RelNode.prettyPrint()

Constructor Summary

Constructors

Constructor	Description
PrettyPrinter()

Method Summary

Modifier and Type	Method	Description
String	visit(AggregationNode node)	Visits an aggregation (γ) node.
String	visit(AntiJoinNode node)	Visits an anti-join (▷) node.
String	visit(AsOfJoinNode node)	Visits an AS-OF temporal join (ASOF) node.
String	visit(ClosureNode node)	Visits a transitive-closure (CLOSURE/RCLOSURE) node.
String	visit(ClusterNode node)	Visits a connected-components (CLUSTER) node.
String	visit(CompositionNode node)	Visits a relational composition (∘) node.
String	visit(CoverNode node)	Visits a covering-reduction (COVER) node.
String	visit(DifferenceNode node)	Visits a set difference (−) node.
String	visit(DistinctNode node)	Visits a distinct (δ) node.
String	visit(DivisionNode node)	Visits a relational division (÷) node.
String	visit(DownsampleNode node)	Visits a time-series downsampling (DOWNSAMPLE) node.
String	visit(EmptyRelationNode node)	Renders the optimizer-introduced empty relation as ∅⟨heading⟩.
String	visit(FixpointNode node)	Visits a general-recursion fixpoint (FIX) node.
String	visit(FullOuterJoinNode node)	Visits a full outer join (⟗) node.
String	visit(IntersectionNode node)	Visits a set intersection (∩) node.
String	visit(IntervalJoinNode node)	Visits an interval join (IJOIN) node.
String	visit(IterateNode node)	Visits a replace-each-round iteration (ITERATE) node.
String	visit(LateralJoinNode node)	Visits a lateral (correlated) table-valued function join node.
String	visit(LeftOuterJoinNode node)	Visits a left outer join (⟕) node.
String	visit(LimitNode node)	Visits a limit (λ) node.
String	visit(NaturalJoinNode node)	Visits a natural join (⋈) node.
String	visit(OptimizeNode node)	Visits a declarative-optimisation (OPTIMIZE) node.
String	visit(OuterUnionNode node)	Visits an outer-union (⊔) node.
String	visit(PairwiseUniversalNode node)	Visits a pairwise-universal semi-join (USEMI) node.
String	visit(PathNode node)	Visits a bounded variable-length path (PATH) node.
String	visit(PivotNode node)	Visits a row-pivoting (PIVOT) node.
String	visit(ProductNode node)	Visits a Cartesian product (×) node.
String	visit(ProjectionNode node)	Visits a projection (π) node.
String	visit(RecursiveRefNode node)	Visits a recursive-reference (FIX- or ITERATE-bound name) node.
String	visit(RelationFunctionCall node)	Visits a table-valued (relation-returning) function call.
String	visit(RelationNode node)	Visits a base relation reference.
String	visit(RenameNode node)	Visits a rename (ρ) node.
String	visit(ReservoirSampleNode node)	Visits a reservoir (fixed-count) sampling (SAMPLE … ROWS) node.
String	visit(RightOuterJoinNode node)	Visits a right outer join (⟖) node.
String	visit(SampleNode node)	Visits a Bernoulli-sampling (SAMPLE) node.
String	visit(SelectionNode node)	Visits a selection (σ) node.
String	visit(SemiJoinNode node)	Visits a semi-join (⋉) node.
String	visit(SessionizeNode node)	Visits a gap-and-island / sessionization (SESSIONIZE) node.
String	visit(SolveNode node)	Visits a goal-seek (SOLVE) node.
String	visit(SortNode node)	Visits a sort (τ) node.
String	visit(SymmetricDifferenceNode node)	Visits a symmetric-difference (∆) node.
String	visit(ThetaJoinNode node)	Visits a theta join (⨝) node.
String	visit(TopKNode node)	Visits a top-k-per-group (TOP) node.
String	visit(TraceNode node)	Visits an optimal-path extraction (TRACE) node.
String	visit(TreeNode node)	Visits an adjacency-to-forest nesting (TREE) node.
String	visit(TruthRelationNode node)	Visits a nullary truth-relation literal (UNIT/DEE or EMPTY/DUM).
String	visit(UnionAllNode node)	Visits a multiset union (⊎) node.
String	visit(UnionNode node)	Visits a set union (∪) node.
String	visit(UniversalNode node)	Visits a universal-quantification (∀) node.
String	visit(UnnestNode node)	Visits an unnest (μ) node.
String	visit(UnpivotNode node)	Visits a column-folding (UNPIVOT) node.
String	visit(WhyNode node)	Visits a lineage-reification (WHY) node.
String	visit(WindowNode node)	Visits a window (ROLLING / WINDOW) node.

Methods inherited from class java.lang.Object

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

Constructor Details

PrettyPrinter

public PrettyPrinter()

Method Details

visit

public String visit(RelationNode node)

Description copied from interface: RelNodeVisitor

Visits a base relation reference.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(RelationFunctionCall node)

Description copied from interface: RelNodeVisitor

Visits a table-valued (relation-returning) function call.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(TruthRelationNode node)

Description copied from interface: RelNodeVisitor

Visits a nullary truth-relation literal (UNIT/DEE or EMPTY/DUM).

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(EmptyRelationNode node)

Renders the optimizer-introduced empty relation as ∅⟨heading⟩.

This is the one node whose printed form does not parse back: EmptyRelationNode has no surface syntax, because only the optimizer creates it. The form is still injective — two empty relations print alike exactly when their headings do — which is the property AstEquivalence relies on; it is the round-trip that is unavailable, and only for a node the parser can never produce.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(ProjectionNode node)

Description copied from interface: RelNodeVisitor

Visits a projection (π) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SelectionNode node)

Description copied from interface: RelNodeVisitor

Visits a selection (σ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(RenameNode node)

Description copied from interface: RelNodeVisitor

Visits a rename (ρ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(NaturalJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a natural join (⋈) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(ThetaJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a theta join (⨝) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(LeftOuterJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a left outer join (⟕) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(RightOuterJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a right outer join (⟖) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(FullOuterJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a full outer join (⟗) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SemiJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a semi-join (⋉) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(AntiJoinNode node)

Description copied from interface: RelNodeVisitor

Visits an anti-join (▷) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(PairwiseUniversalNode node)

Description copied from interface: RelNodeVisitor

Visits a pairwise-universal semi-join (USEMI) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(AsOfJoinNode node)

Description copied from interface: RelNodeVisitor

Visits an AS-OF temporal join (ASOF) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(IntervalJoinNode node)

Description copied from interface: RelNodeVisitor

Visits an interval join (IJOIN) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(ProductNode node)

Description copied from interface: RelNodeVisitor

Visits a Cartesian product (×) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(UnionNode node)

Description copied from interface: RelNodeVisitor

Visits a set union (∪) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(UnionAllNode node)

Description copied from interface: RelNodeVisitor

Visits a multiset union (⊎) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(OuterUnionNode node)

Description copied from interface: RelNodeVisitor

Visits an outer-union (⊔) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(DifferenceNode node)

Description copied from interface: RelNodeVisitor

Visits a set difference (−) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(IntersectionNode node)

Description copied from interface: RelNodeVisitor

Visits a set intersection (∩) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(DivisionNode node)

Description copied from interface: RelNodeVisitor

Visits a relational division (÷) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SymmetricDifferenceNode node)

Description copied from interface: RelNodeVisitor

Visits a symmetric-difference (∆) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(CompositionNode node)

Description copied from interface: RelNodeVisitor

Visits a relational composition (∘) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(UniversalNode node)

Description copied from interface: RelNodeVisitor

Visits a universal-quantification (∀) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SampleNode node)

Description copied from interface: RelNodeVisitor

Visits a Bernoulli-sampling (SAMPLE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(ReservoirSampleNode node)

Description copied from interface: RelNodeVisitor

Visits a reservoir (fixed-count) sampling (SAMPLE … ROWS) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SolveNode node)

Description copied from interface: RelNodeVisitor

Visits a goal-seek (SOLVE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(OptimizeNode node)

Description copied from interface: RelNodeVisitor

Visits a declarative-optimisation (OPTIMIZE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(TopKNode node)

Description copied from interface: RelNodeVisitor

Visits a top-k-per-group (TOP) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(AggregationNode node)

Description copied from interface: RelNodeVisitor

Visits an aggregation (γ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SortNode node)

Description copied from interface: RelNodeVisitor

Visits a sort (τ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(LimitNode node)

Description copied from interface: RelNodeVisitor

Visits a limit (λ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(DistinctNode node)

Description copied from interface: RelNodeVisitor

Visits a distinct (δ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(WhyNode node)

Description copied from interface: RelNodeVisitor

Visits a lineage-reification (WHY) node.

A default that throws rather than an abstract method: a visitor with no meaningful answer for a lineage reification inherits the failure instead of being forced to carry a stub. Visitors that do handle it — schema inference, validation, cost, planning, execution — override this method.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(UnnestNode node)

Description copied from interface: RelNodeVisitor

Visits an unnest (μ) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(ClosureNode node)

Description copied from interface: RelNodeVisitor

Visits a transitive-closure (CLOSURE/RCLOSURE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(ClusterNode node)

Description copied from interface: RelNodeVisitor

Visits a connected-components (CLUSTER) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(PathNode node)

Description copied from interface: RelNodeVisitor

Visits a bounded variable-length path (PATH) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(TraceNode node)

Description copied from interface: RelNodeVisitor

Visits an optimal-path extraction (TRACE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(CoverNode node)

Description copied from interface: RelNodeVisitor

Visits a covering-reduction (COVER) node.

A default that throws rather than an abstract method: a visitor with no meaningful answer for a covering reduction inherits the failure instead of being forced to carry a stub. Visitors that do handle it — schema inference, validation, the executor — override this method.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(DownsampleNode node)

Description copied from interface: RelNodeVisitor

Visits a time-series downsampling (DOWNSAMPLE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(WindowNode node)

Description copied from interface: RelNodeVisitor

Visits a window (ROLLING / WINDOW) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(SessionizeNode node)

Description copied from interface: RelNodeVisitor

Visits a gap-and-island / sessionization (SESSIONIZE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(TreeNode node)

Description copied from interface: RelNodeVisitor

Visits an adjacency-to-forest nesting (TREE) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(UnpivotNode node)

Description copied from interface: RelNodeVisitor

Visits a column-folding (UNPIVOT) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(PivotNode node)

Description copied from interface: RelNodeVisitor

Visits a row-pivoting (PIVOT) node.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(FixpointNode node)

Description copied from interface: RelNodeVisitor

Visits a general-recursion fixpoint (FIX) node.

A default that throws rather than an abstract method: a visitor with no meaningful answer for a least fixpoint inherits the failure instead of being forced to carry a stub. Visitors that do handle it — schema inference, validation, the semi-naïve executor — override this method.

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(IterateNode node)

Description copied from interface: RelNodeVisitor

Visits a replace-each-round iteration (ITERATE) node.

Provided as a default that throws — see RelNodeVisitor.visit(FixpointNode).

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(RecursiveRefNode node)

Description copied from interface: RelNodeVisitor

Visits a recursive-reference (FIX- or ITERATE-bound name) node.

Provided as a default that throws — see RelNodeVisitor.visit(FixpointNode).

Specified by:

visit in interface RelNodeVisitor<String>

visit

public String visit(LateralJoinNode node)

Description copied from interface: RelNodeVisitor

Visits a lateral (correlated) table-valued function join node.

A default that throws rather than an abstract method: a visitor with no meaningful answer for a correlated TVF join inherits the failure instead of being forced to carry a stub. Visitors that do handle it — schema inference, validation, the executor — override this method.

Specified by:

visit in interface RelNodeVisitor<String>