WITH                         Record Expansion                         pp 81


 Define:  A With statements consists of the reserved word With
          followed by a list of record variables separated by commas,
          followed by the reserved word Do and finally a statement.

 Purpose: With 'opens up' a record so that the field identifiers may
          be used as simple variable identifiers.

 Notes:   The use of records does sometimes result in lengthy statements.
          It is much easier to access record fields as if they were simple
          variables.



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 Usage:
       TYPE
          Name   = Record
                   FamilyName  : String [32];
                   GivenNames  : Array [1..4] of String [16];
                   End;

          Rate   = Record
                   Normal      : Integer;
                   Overtime    : Integer;
                   Nights      : Integer;
                   Weekend     : Integer;
                   End;

          Date   = Record
                   Day         : 1..31;
                   Month       : (Jan,Feb,Mar,Apr,May,Jun,
                                  Jul,Aug,Sep,Oct,Nov,Dec);
                   Year        : 1900..1999;
                   End;

          Person = Record
                   ID          : Name;
                   Time        : Date;
                   End;

          Wages  = Record
                   Individual  : Person;
                   Cost        : Rate;
                   End;

       VAR
          Salary               : Wages;
          Fee                  : Wages;

       BEGIN
          Salary                          := Fee;
          Salary.Cost.Overtime            := 950;
          Salary.Individual.Time          := Fee.Individual.Time;
          Salary.Individual.ID.FamilyName := 'Smith';

          { Expand Wages record }
          With Salary Do
            Begin
            Cost.Overtime                 := 950;
            Individual.ID.FamilyName      := 'Smith';
            End;

          { Expand Wages/Person/Name/Date records }
          With Salary, Individual, ID, Time do
            Begin
            FamilyName                    := 'Smith';
            GivenNames[1]                 := 'Billy';
            GivenNames[2]                 := 'Joe';
            GivenNames[3]                 := 'Jim';
            GivenNames[4]                 := 'Bob';
            Day                           := 4;
            Month                         := Nov;
            Year                          := 1950;
            End;
       END.


Salary                           { Record of Wages                          }
  Wages                          { Record of Individual/Cost                }
    Individual                   { Record of Person                         }
      Person                     { Record of ID/Time                        }
        ID                       { Record of Name                           }
          Name                   { Record of FamilyName/GivenNames          }
            FamilyName           { Field of Name record                     }
            GivenName            { Field of Name record                     }
        Time                     { Record of Date                           }
          Date                   { Record of Day/Month/Year                 }
            Day                  { Field of Date                            }
            Month                { Field of Date                            }
            Year                 { Field of Date                            }
    Cost                         { Record of Rate                           }
      Rate                       { Record of Normal/Overtime/Nights/Weekend }
        Normal                   { Field of Rate                            }
        Overtime                 { Field of Rate                            }
        Nights                   { Field of Rate                            }
        Weekend                  { Field of Rate                            }