Record Class SymbolicTermValue

java.lang.Object
java.lang.Record
org.ek9lang.compiler.phase5.flow.SymbolicTermValue
Record Components:
name - the term's name (today the source symbol name; hardening: key by symbol identity)
All Implemented Interfaces:
AbstractValue
public record SymbolicTermValue(String name) extends Record implements AbstractValue
A symbolic (named) term in the flow lattice — a fresh, unconstrained parameter or local carried as itself instead of collapsing to TopValue.

This is the value the ∃-polarity symbolic engine (the Contract/Symbolic scanner, M3) seeds where the analyzer would otherwise record TOP. TOP means "no information" and collapses at a branch merge; a symbolic term means "some specific but unknown input value", and it must survive a merge so a path condition can be accumulated across branches. That survival is the entire mechanism: join(AbstractValue) returns this when merged with the same named term (both paths agree it is the same input), and widens to TOP otherwise — so it rides the existing ConstraintState/branch-stack unchanged, with no parallel store.

It is deliberately NOT known-set (see AbstractValue.isKnownSet()): the engine reasons about "for some input", so a symbolic term must never be treated as a proven value. It answers evaluateCondition(String, AbstractValue) as UNKNOWN — relational reasoning about terms is done by the orthogonal PathCondition, not by the per-value lattice.

Design proven by spikes S1/S3 (see EK9_SYMBOLIC_SCANNER_IMPLEMENTATION_SPEC.md §11 and the preserved body in EK9_SYMBOLIC_SCANNER_SPIKE_REFERENCE.md §4.2): the only change to existing lattice code is adding this to the AbstractValue permits clause + one isKnownSet case.

  • Constructor Details

    • SymbolicTermValue

      public SymbolicTermValue(String name)
      Creates an instance of a SymbolicTermValue record class.
      Parameters:
      name - the value for the name 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 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.

    • name

      public String name()
      Returns the value of the name record component.
      Returns:
      the value of the name record component