Record Class BottomValue

java.lang.Object
java.lang.Record
org.ek9lang.compiler.phase5.flow.BottomValue
All Implemented Interfaces:
AbstractValue
public record BottomValue() extends Record implements AbstractValue
Represents an unreachable program point — a contradiction in constraints.

This is the bottom of the lattice. A state becomes BOTTOM after a throw statement or when a condition creates a contradiction (e.g., x == 5 when x is known to be 7).

Key property: BOTTOM join X = X (unreachable paths are ignored at join points).

Singleton — use INSTANCE.

  • Field Details

    • INSTANCE

      public static final BottomValue INSTANCE
      Shared singleton instance.

  • Constructor Details

    • BottomValue

      public BottomValue()
      Creates an instance of a BottomValue record class.

  • Method Details

    • join

      public AbstractValue join(AbstractValue other)
      Description copied from interface: AbstractValue
      Join this value with another at a branch convergence point. Returns the least upper bound of the two values.

      Key rules:

      • BOTTOM join X = X (unreachable path is ignored)
      • X join BOTTOM = X
      • TOP join X = TOP
      • Constant(a) join Constant(a) = Constant(a) (both agree)
      • Constant(a) join Constant(b) = TOP (disagreement)
      Specified by:
      join in interface AbstractValue

    • evaluateCondition

      public ConditionResult evaluateCondition(String operator, AbstractValue operand)
      Description copied from interface: AbstractValue
      Evaluate whether this abstract value satisfies a comparison condition.
      Specified by:
      evaluateCondition in interface AbstractValue
      Parameters:
      operator - the comparison operator (==, <>, <, >, etc.)
      operand - the right-hand side value to compare against
      Returns:
      TRUE if condition is always satisfied, FALSE if never satisfied, UNKNOWN if indeterminate

    • isKnown

      public boolean isKnown()
      Description copied from interface: AbstractValue
      Check if this value represents a known state (not TOP and not BOTTOM).
      Specified by:
      isKnown in interface AbstractValue

    • isBottom

      public boolean isBottom()
      Description copied from interface: AbstractValue
      Check if this value represents an unreachable program point.
      Specified by:
      isBottom in interface AbstractValue

    • toString

      public 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.
      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.