Package org.eclipse.rdf4j.federated.algebra

## Interface VariableExpr

- All Known Subinterfaces:
    `ExclusiveTupleExpr`, `ExclusiveTupleExprRenderer`, `FedXTupleExpr`, `StatementTupleExpr`
  All Known Implementing Classes:
    `CheckStatementPattern`, `ExclusiveArbitraryLengthPath`, `ExclusiveGroup`, `ExclusiveStatement`, `FedXStatementPattern`, `PassThroughTupleExpr`, `StatementSourcePattern`

      public interface VariableExpr

  Interface for algebra nodes that can return the free variables of the expression.
  Author:
    Andreas Schwarte
  See Also:
    `QueryAlgebraUtil.getFreeVars(org.eclipse.rdf4j.query.algebra.TupleExpr)`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `List<String>` | `getFreeVars()` |

- - ### Method Detail

    - #### getFreeVars

          List<String> getFreeVars()

      Returns:
        a list of free (i.e. unbound) variables in this expression