Package li.selman.jpbe.dsl.position

Class ConstantPosition

java.lang.Object
li.selman.jpbe.dsl.position.ConstantPosition
All Implemented Interfaces:
DslElement, Position
public class ConstantPosition extends Object implements Position
Denotes a constant index of a string. If constant is positive, the index is counted from the left — just like String.charAt(int).

If the constant is negative, the index is counted from the right. In that case the last index of a string is denoted with the value in LAST_POSITION_INDEX as 0 is already reserved for the "positive" index way of counting.

  • Constructor Details

    • ConstantPosition

      public ConstantPosition(int constant)
      Parameters:
      constant - signed integer denoting the index on any string

  • Method Details

    • lastPosition

      public static ConstantPosition lastPosition()

    • evalToPosition

      public int evalToPosition(String s)
      Description copied from interface: Position
      Given an input, dynamically evaluate to an index inside for string manipulation operations.
      Specified by:
      evalToPosition in interface Position
      Parameters:
      s - input
      Returns:
      the index

    • getDslWeight

      public int getDslWeight()
      Description copied from interface: DslElement
      The weight can be used to find an optimal program in a set of valid programs. "Optimal" is subjective and can go into different directions. Some examples include:
      • Weight by how expensive a DSL element is to execute.
        Weight by how likely a DSL element is to be part of a generic full program. A ConstantPosition generally is less generic. Thus, the user has to specify their intent more often to finish their wrangling task.
      • Specified by:
      getDslWeight in interface DslElement
      Returns:
      the weight of the DSL element

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object