Module com.darkcollective.relix.semantic

Package com.darkcollective.relix.semantic.internal

Class PredicateValidator

java.lang.Object

com.darkcollective.relix.semantic.internal.PredicateValidator

All Implemented Interfaces:

PredicateVisitor<Void>

public final class PredicateValidator
extends Object
implements PredicateVisitor<Void>

Validates attribute references and function calls within a predicate tree.

Used by RelAlgebraValidator to check the boolean conditions that appear in:

• Selection nodes (σ) — predicate checked against the input relation's schema.
• Conditioned join nodes (⋈, ⟕, ⟖, ⟗, ⋉, ▷) — predicate checked against the combined left+right schema produced by the visitor's schema concatenation.

Checks performed

• AttributeOperand — the column name (qualifier stripped) must exist in the available schema.
• FunctionCall — the function must be registered in the symbol table, and the argument count must match at least one overload. Arguments are recursively validated.
• Compound operands (BinaryArithmeticExpression, UnaryOperand, SetLiteralOperand) — recursed into.
• Compound predicates (AndPredicate, OrPredicate, NotPredicate) — recursed into.
• Literals (NumberOperand, StringOperand, BooleanOperand) — no checks needed.

All errors are appended to the mutable errors list supplied at construction time; the visitor never throws.

Method Summary

Modifier and Type	Method	Description
Void	visit(AndPredicate node)	Visits a logical conjunction (∧).
Void	visit(ComparisonPredicate node)	Visits a comparison predicate (=, ≠, <, ≤, >, ≥).
Void	visit(ElementOfPredicate node)	Visits a set-membership test (∈ or ∉).
Void	visit(NotPredicate node)	Visits a logical negation (¬).
Void	visit(NullPredicate node)	Visits a null test (= ⊥ or ≠ ⊥).
Void	visit(OrPredicate node)	Visits a logical disjunction (∨).
Void	visit(PatternPredicate node)	Visits a pattern-matching test (LIKE or NOT LIKE).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

visit

public Void visit(AndPredicate node)

Description copied from interface: PredicateVisitor

Visits a logical conjunction (∧).

Specified by:

visit in interface PredicateVisitor<Void>

visit

public Void visit(OrPredicate node)

Description copied from interface: PredicateVisitor

Visits a logical disjunction (∨).

Specified by:

visit in interface PredicateVisitor<Void>

visit

public Void visit(NotPredicate node)

Description copied from interface: PredicateVisitor

Visits a logical negation (¬).

Specified by:

visit in interface PredicateVisitor<Void>

visit

public Void visit(ComparisonPredicate node)

Description copied from interface: PredicateVisitor

Visits a comparison predicate (=, ≠, <, ≤, >, ≥).

Specified by:

visit in interface PredicateVisitor<Void>

visit

public Void visit(NullPredicate node)

Description copied from interface: PredicateVisitor

Visits a null test (= ⊥ or ≠ ⊥).

Specified by:

visit in interface PredicateVisitor<Void>

visit

public Void visit(ElementOfPredicate node)

Description copied from interface: PredicateVisitor

Visits a set-membership test (∈ or ∉).

Specified by:

visit in interface PredicateVisitor<Void>

visit

public Void visit(PatternPredicate node)

Description copied from interface: PredicateVisitor

Visits a pattern-matching test (LIKE or NOT LIKE).

Specified by:

visit in interface PredicateVisitor<Void>