Package com.e1c.langtool.history.db.query

Interface IExpression

All Known Subinterfaces:
ICriteria, IOperation
All Known Implementing Classes:
Criteria, Operation
public interface IExpression
A query expression that is common interface for criteries and operations.

This interface encapsulates query expressions to select translations from a storage in scope of project. An expression is base interface for two types of terms that composes an expression:

  • criteria to describe single predicate of expression from comparing the field with some value
  • operation to compose criteries and other operations to a tree

To iterate through terms of the expression using the visitor pattern. IExpressionVisitor allows iterating over criteries and operations in necessary way without changing the structure of the tree.

In this way IExpression is a simplified abstract syntax tree of query predicate to select translations from the storage.

Note that it's highly recommended using the special expression builders like ExpressionBuilder to create expressions based on operations.

See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    accept(IExpressionVisitor visitor)
    Accepts the given expression visitor.

  • Method Details

    • accept

      void accept(IExpressionVisitor visitor)
      Accepts the given expression visitor.

      The visitor's visit method is called with this expression.

      Parameters:
      visitor - the visitor