Package org.apache.poi.ss.formula.ptg

Class Ptg

java.lang.Object
org.apache.poi.ss.formula.ptg.Ptg
All Implemented Interfaces:
Duplicatable, GenericRecord
Direct Known Subclasses:
ArrayPtg, ControlPtg, OperandPtg, OperationPtg, ScalarConstantPtg, UnknownPtg
public abstract class Ptg extends Object implements Duplicatable, GenericRecord
Ptg represents a syntactic token in a formula. 'PTG' is an acronym for 'parse thing'. Originally, the name referred to the single byte identifier at the start of the token, but in POI, Ptg encapsulates the whole formula token (initial byte + value data).

Ptgs are logically arranged in a tree representing the structure of the parsed formula. However, in BIFF files Ptgs are written/read in Reverse-Polish Notation order. The RPN ordering also simplifies formula evaluation logic, so POI mostly accesses Ptgs in the same way.

  • Field Details

  • Constructor Details

    • Ptg

      protected Ptg()

    • Ptg

      protected Ptg(Ptg other)

  • Method Details

    • readTokens

      public static Ptg[] readTokens(int size, LittleEndianInput in)
      Reads size bytes of the input stream, to create an array of Ptgs. Extra data (beyond size) may be read if and ArrayPtgs are present.

    • createPtg

      public static Ptg createPtg(LittleEndianInput in)

    • getEncodedSize

      public static int getEncodedSize(Ptg[] ptgs)
      This method will return the same result as getEncodedSizeWithoutArrayData(Ptg[]) if there are no array tokens present.
      Returns:
      the full size taken to encode the specified Ptgs

    • getEncodedSizeWithoutArrayData

      public static int getEncodedSizeWithoutArrayData(Ptg[] ptgs)
      Used to calculate value that should be encoded at the start of the encoded Ptg token array;
      Returns:
      the size of the encoded Ptg tokens not including any trailing array data.

    • serializePtgs

      public static int serializePtgs(Ptg[] ptgs, byte[] array, int offset)
      Writes the ptgs to the data buffer, starting at the specified offset.
      The 2 byte encode length field is not written by this method.
      Returns:
      number of bytes written

    • getSize

      public abstract int getSize()
      Returns:
      the encoded length of this Ptg, including the initial Ptg type identifier byte.

    • write

      public abstract void write(LittleEndianOutput out)

    • toFormulaString

      public abstract String toFormulaString()
      return a string representation of this token alone

    • toString

      public final String toString()
      Overrides:
      toString in class Object

    • setClass

      public final void setClass(byte thePtgClass)

    • getPtgClass

      public final byte getPtgClass()
      Returns:
      the 'operand class' (REF/VALUE/ARRAY) for this Ptg

    • getRVAType

      public final char getRVAType()
      Debug / diagnostic method to get this token's 'operand class' type.
      Returns:
      'R' for 'reference', 'V' for 'value', 'A' for 'array' and '.' for base tokens

    • getDefaultOperandClass

      public abstract byte getDefaultOperandClass()

    • isBaseToken

      public abstract boolean isBaseToken()
      Returns:
      false if this token is classified as 'reference', 'value', or 'array'

    • doesFormulaReferToDeletedCell

      public static boolean doesFormulaReferToDeletedCell(Ptg[] ptgs)

    • copy

      public abstract Ptg copy()
      Specified by:
      copy in interface Duplicatable
      Returns:
      a deep copy of the implementing class / instance

    • getSid

      public abstract byte getSid()
      Returns:
      structure id of the parsed thing, or -1 if the record has no sid