PackageData.ulam

transient PackageData {
  typedef DataUtils.Datum Datum;
  typedef DataUtils.Byte Byte;
  typedef DataUtils.Integer Integer;
  typedef ITaggable.Tag Tag;

  typedef Unsigned(2) Arity;
  typedef Unsigned(2) Type;

  typedef Byte Symbol;

  constant Datum cNO_DATA = 0x0;
  constant Byte cNIL = 0x0;

  constant Type cTYPE_BLOCK       = 0;
  constant Type cTYPE_FUNCTION    = 1;
  constant Type cTYPE_CONDITIONAL = 2;
  constant Type cTYPE_CONSTANT    = 3;

  // Data
  //
  // arity  type unused        symbol/value
  //   v     v     v             v
  // | 0 1 | 2 3 | 4 5 | 6 | 7 | 0 1 2 3 4 5 6 7
  //                     ^   ^
  //             executable? has value?
  //
  constant Byte cARITY_MASK = 0b11000000;
  constant Unsigned cARITY_SHIFT = 6;

  constant Byte cTYPE_MASK = 0b00110000;
  constant Unsigned cTYPE_SHIFT = 4;

  constant Byte cIS_EXEC_MASK = 0b00000010;
  constant Unsigned cIS_EXEC_SHIFT = 1;

  // Aux
  // Non-executable: tag
  // Executable: either final result of node evaluation or stored 1st argument
  //
  //  unused    active/final? tag/value
  //   v               v       v
  // | 0 1 2 3 4 | 5 | 6 | 7 | 0 1 2 3 4 5 6 7
  //               ^       ^
  //             active   has value?
  //             default

  // Aux: non-executable
  constant Byte cIS_ACTIVE_DEFAULT_MASK = 0b00000100;
  constant Unsigned cIS_ACTIVE_DEFAULT_SHIFT = 2;

  constant Byte cIS_ACTIVE_MASK = 0b00000010;
  constant Unsigned cIS_ACTIVE_SHIFT = 1;

  // Aux: executable
  constant Byte cIS_FINAL_MASK = cIS_ACTIVE_MASK;
  constant Unsigned cIS_FINAL_SHIFT = cIS_ACTIVE_SHIFT;

  // Common
  constant Byte cHAS_VALUE_MASK = 0b00000001;
  constant Unsigned cHAS_VALUE_SHIFT = 0;

  DataUtils dd;

  // Data

  Arity getArity(Datum datum) {
    return (Arity) dd.getHi(datum, cARITY_MASK, cARITY_SHIFT);
  }

  Datum setArity(Datum datum, Arity arity) {
    return dd.setHi(datum, arity, cARITY_MASK, cARITY_SHIFT);
  }

  Type getType(Datum datum) {
    return (Type) dd.getHi(datum, cTYPE_MASK, cTYPE_SHIFT);
  }

  Datum setType(Datum datum, Type type) {
    return dd.setHi(datum, type, cTYPE_MASK, cTYPE_SHIFT);
  }

  Bool isExec(Datum datum) {
    return (Bool) dd.getHi(datum, cIS_EXEC_MASK, cIS_EXEC_SHIFT);
  }

  Datum setIsExec(Datum datum, Bool exec) {
    return dd.setHi(datum, (Byte) exec, cIS_EXEC_MASK, cIS_EXEC_SHIFT);
  }

  Symbol getSymbol(Datum datum) {
    return getValue(datum);
  }

  Datum setSymbol(Datum datum, Symbol symbol) {
    return setValue(datum, symbol);
  }

  // Aux (non-executable)

  Bool hasTag(Datum datum) {
    return hasValue(datum);
  }

  Tag getTag(Datum datum) {
    return getValue(datum);
  }

  Datum setTag(Datum datum, Tag tag) {
    return setValue(datum, tag);
  }

  // Aux: non-executable

  Bool isActiveDefault(Datum datum) {
    return (Bool) dd.getHi(datum, cIS_ACTIVE_DEFAULT_MASK, cIS_ACTIVE_DEFAULT_SHIFT);
  }

  Datum setIsActiveDefault(Datum datum, Bool isActive) {
    return dd.setHi(datum, (Byte) isActive, cIS_ACTIVE_DEFAULT_MASK, cIS_ACTIVE_DEFAULT_SHIFT);
  }


  Bool isActive(Datum datum) {
    return (Bool) dd.getHi(datum, cIS_ACTIVE_MASK, cIS_ACTIVE_SHIFT);
  }

  Datum setIsActive(Datum datum, Bool isActive) {
    return dd.setHi(datum, (Byte) isActive, cIS_ACTIVE_MASK, cIS_ACTIVE_SHIFT);
  }


  Datum resetIsActive(Datum datum) {
    return setIsActive(datum, isActiveDefault(datum));
  }

  // Aux: executable

  Bool isFinal(Datum datum) {
    return (Bool) dd.getHi(datum, cIS_FINAL_MASK, cIS_FINAL_SHIFT);
  }

  Datum setIsFinal(Datum datum, Bool isFinal) {
    return dd.setHi(datum, (Byte) isFinal, cIS_FINAL_MASK, cIS_FINAL_SHIFT);
  }

  // Common

  Bool hasValue(Datum datum) {
    return (Bool) dd.getHi(datum, cHAS_VALUE_MASK, cHAS_VALUE_SHIFT);
  }

  Byte getValue(Datum datum) {
    return dd.getLo(datum);
  }

  Datum setValue(Datum datum, Byte value) {
    datum = dd.setLo(datum, value);
    datum = dd.setHi(datum, 0x1, cHAS_VALUE_MASK, cHAS_VALUE_SHIFT);
    return datum;
  }

  Datum unsValue(Datum datum) {
    datum = dd.setLo(datum, cNIL);
    datum = dd.setHi(datum, 0x0, cHAS_VALUE_MASK, cHAS_VALUE_SHIFT);
    return datum;
  }

  Integer getInteger(Datum datum) {
    return dd.toInteger(getValue(datum));
  }

  Datum setInteger(Datum datum, Integer value) {
    return setValue(datum, dd.fromInteger(value));
  }
}