Module com.darkcollective.relix.ast
Package com.darkcollective.relix.ast

Record Class WhyNode

java.lang.Object
java.lang.Record
com.darkcollective.relix.ast.WhyNode
Record Components:
input - the source relation whose lineage is reified; must not be null
location - the source location of this node; never null
All Implemented Interfaces:
RelNode
public record WhyNode(RelNode input, SourceLocation location) extends Record implements RelNode
Why (ω) — reifies the lineage provenance of input as queryable data.

WHY(R) is a self-terminating reification boundary. Below it the lineage semiring threads exactly as on today's provenance side-channel; at it each result tuple's lineage polynomial is frozen into one added nested column; above it the value is inert data that ordinary σ/π/μ views slice. It is therefore not the rejected always-on annotation column — nothing above WHY is re-threaded.

Output schema: input columns ⊕ provenance:ANY, where the appended provenance column holds the tuple's polynomial as a faithful two-level document: [{coefficient, variables:[{relation, ordinal, columns}]}] — one array element per monomial (distinct derivation), one variables element per contributing base-tuple occurrence.

Evaluation reuses the existing lineage K-relation path (ProvenanceEvaluator over the polynomial semiring) — no new evaluation concepts. The canonical K-relation must be built before output, so the operator is blocking (MaterializationMode.BAG), and it is a hard optimizer barrier that never pushes down.

Surface syntax: WHY (R) (ASCII) or ω (R) (glyph).

  • Field Details

    • PROVENANCE_COLUMN

      public static final String PROVENANCE_COLUMN
      The reserved name of the appended provenance column (provenance). The reification adds one column of this name at type ANY; a clash with an existing input column is a validation error — there is no ρ-style rename escape hatch.
      See Also:

  • Constructor Details

    • WhyNode

      public WhyNode(RelNode input, SourceLocation location)
      Creates an instance of a WhyNode record class.
      Parameters:
      input - the value for the input record component
      location - the value for the location record component

    • WhyNode

      public WhyNode(RelNode input)
      Convenience constructor for tests; uses SourceLocation.UNKNOWN.

  • Method Details

    • accept

      public <R> R accept(RelNodeVisitor<R> visitor)
      Specified by:
      accept in interface RelNode

    • toString

      public final String toString()
      Returns a string representation of this record class. The representation contains the name of the class, followed by the name and value of each of the record components.
      Specified by:
      toString in class Record
      Returns:
      a string representation of this object

    • hashCode

      public final int hashCode()
      Returns a hash code value for this object. The value is derived from the hash code of each of the record components.
      Specified by:
      hashCode in class Record
      Returns:
      a hash code value for this object

    • equals

      public final boolean equals(Object o)
      Indicates whether some other object is "equal to" this one. The objects are equal if the other object is of the same class and if all the record components are equal. All components in this record class are compared with Objects::equals(Object,Object).
      Specified by:
      equals in class Record
      Parameters:
      o - the object with which to compare
      Returns:
      true if this object is the same as the o argument; false otherwise.

    • input

      public RelNode input()
      Returns the value of the input record component.
      Returns:
      the value of the input record component

    • location

      public SourceLocation location()
      Returns the value of the location record component.
      Specified by:
      location in interface RelNode
      Returns:
      the value of the location record component