Record Class CollectionStateValue

java.lang.Object
java.lang.Record
org.ek9lang.compiler.phase5.flow.CollectionStateValue
All Implemented Interfaces:
AbstractValue
public record CollectionStateValue(boolean isSet, boolean isEmpty) extends Record implements AbstractValue
Represents a variable known to be a collection or container type with both SET/UNSET and EMPTY/NON-EMPTY state tracked.

Extends the lattice for built-in collection and container types (List, Dict, Optional, Result) whose construction semantics provide compile-time knowledge of both their isSet state and their emptiness state.

Examples:

  • List() of String → SET and EMPTY (created but no elements)
  • [1, 2, 3] → SET and NON-EMPTY (literal list with elements)
  • Dict() of (String, Integer) → SET and EMPTY
  • {"key": 1} → SET and NON-EMPTY (literal dict with entries)
  • Optional("hello") → SET and NON-EMPTY (has a value)
  • Optional() of String → UNSET and EMPTY (no value)

Lattice join rules:

  • Same state join same state = same state
  • Different states = TOP (disagreement)
  • CollectionStateValue(SET, _) join SetStateValue(SET) = this (more precise)
  • CollectionStateValue(SET, _) join ConstantValue = ConstantValue (more precise)
  • CollectionStateValue(UNSET, _) join SetStateValue(SET) = TOP (disagreement)

  • Field Details

    • SET_AND_EMPTY

      public static final CollectionStateValue SET_AND_EMPTY
      Collection/container that is SET and EMPTY (e.g., List() of String).

    • SET_AND_NON_EMPTY

      public static final CollectionStateValue SET_AND_NON_EMPTY
      Collection/container that is SET and NON-EMPTY (e.g., [1, 2, 3]).

    • UNSET_AND_EMPTY

      public static final CollectionStateValue UNSET_AND_EMPTY
      Collection/container that is UNSET and EMPTY (e.g., Optional() of String).

  • Constructor Details

    • CollectionStateValue

      public CollectionStateValue(boolean isSet, boolean isEmpty)
      Creates an instance of a CollectionStateValue record class.
      Parameters:
      isSet - the value for the isSet record component
      isEmpty - the value for the isEmpty record component

  • 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. All components in this record class are compared with the compare method from their corresponding wrapper classes.
      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.

    • isSet

      public boolean isSet()
      Returns the value of the isSet record component.
      Returns:
      the value of the isSet record component

    • isEmpty

      public boolean isEmpty()
      Returns the value of the isEmpty record component.
      Returns:
      the value of the isEmpty record component