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

Record Class CompositionNode

java.lang.Object
java.lang.Record
com.darkcollective.relix.ast.CompositionNode
Record Components:
left - the left input relation; must not be null
right - the right input relation; must not be null
location - the source location of this node; never null
All Implemented Interfaces:
RelNode
public record CompositionNode(RelNode left, RelNode right, SourceLocation location) extends Record implements RelNode
Relational composition (∘) — composes two relations on their shared columns, like function composition. For R(a, b) ∘ S(b, c) the result relates a to c: it natural-joins the two inputs on their common columns and then projects those shared columns away.

Equivalent to π (non-shared columns) (R ⋈ S), but composition is a named algebraic operation in its own right (and division's sibling), so it is a first-class operator rather than that join-then-project idiom.

Example: (R) ∘ (S)

  • Constructor Details

    • CompositionNode

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

    • CompositionNode

      public CompositionNode(RelNode left, RelNode right)
      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.

    • left

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

    • right

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