Sort Fields

Table of Contents

[func]
user_sort (integer custom_compare, sequence data, object userdata)

Sort a sequence using a user-defined comparision function.

Returns: SEQUENCE: The sorted version of data

customer_compare is the routine_id of a user defined function that returns -1, 0, or 1 to indicate the result of comparing any two elements in data. The user defined function is called as many times as required by user_sort() to order the elements in data.
data is the sequence to sort. It contain anything and the user defined comparision function is assumed to be able to compare any two elements in the data.
userdata is some data that is passed to the user-defined function on each call to it. It is passed unchanged as user_sort does not look at it in any way. This is used to pass some meaningful information to the user defined routine.

Notes:

copyright by Robert Craig of Rapid Deployment Software

Example:

  sorted = user_sort(routine_id("compare_fields"), pData, "Case Insensitive")

See Also: compare_fields , multi_sort

Table of Contents

[func]
compare_fields (object RecordA, object RecordB, object Compare_Defn)

Compares two records based on a set of comparison definitions.

Returns: INTEGER: -1 if RecordA is 'less than' RecordB, +1 if 'greater than' and 0 if they are equal.

RecordA and RecordB are normally a sequence of fields, but this routine will handle records that are not sequences by treating them as if they were a one-field sequence.

Compare_Defn is either a single field number or a list of field comparision definitions. Each field comparision definition is a 2-element sequence of the format {fieldnumber, fieldtype}. If fieldnumber is negative the field is compared in descending order. If fieldnumber is zero the definition is ignored. If fieldnumber is positive the field is compared in ascending sequence.
The fieldtype can be "I" to do a case-insensitive comparision, or "N" to treat text as numeric, in which case fields are converted to numbers before comparing. If a field cannot be converted to a number it is compared as a string.

Example:

  integer Result

  -- Field 2, case-sensitive text
  Result = compare_fields( CustA, CustB, 2)
  -- Field 1, case-insensitive
  Result = compare_fields( CustA, CustB,{ {1,"I"} })
  -- Field 3, case-insensitive, then field 4, numerics, then field 2 descending
  Result = compare_fields( CustA, CustB,{ {3,"I"}, {4,"N"}, -2 })
  -- Field 3, descending, case-insensitive
  Result = compare_fields( CustA, CustB,{ {-3,"I"} })

See Also: user_sort, multi_sort

Table of Contents

[func]
multi_sort (sequence Data, object Sort_Defn)

Sorts a list of records by fields.

Returns: SEQUENCE: The sorted records.

Data is the list of records to be sorted. Each record is normally a sequence of fields, but this routine will handle records that are not sequences by treating them as if they were a one-element sequence.

Sort_Defn is either a single field number or a list of field sorting definitions. Each field sorting definition is a 2-element sequence of the format {fieldnumber, fieldtype}. If fieldnumber is negative the field is sorted in descending sequence. If fieldnumber is zero the sort definition is ignored. If fieldnumber is positive the field is sorted in ascending sequence.
The fieldtype can be "I" to do a case-insensitive sort, or "N" to treat text as numeric, in which case fields are converted to numbers before comparing. If a field cannot be converted to a number it is compared as a string.

Example:

  sequence sorted

  -- Field 2, case-sensitive text
  sorted = multi_sort( unsorted, 2)
  -- Field 1, case-insensitive
  sorted = multi_sort( unsorted,{ {1,"I"} })
  -- Field 3, case-insensitive, then field 4, numerics, then field 2 descending
  sorted = multi_sort( unsorted,{ {3,"I"}, {4,"N"}, -2 })
  -- Field 3, descending, case-insensitive
  sorted = multi_sort( unsorted,{ {-3,"I"} })

See Also: user_sort, compare_fields