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SORT, Specification File Qualifiers, /COLLATING_SEQUENCE
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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Specifies the collating instructions for a sort or merge
operation. With the /COLLATING_SEQUENCE qualifier, you can
specify ASCII (the default), EBCDIC, or Multinational sequence;
you can also define your own sequence.
Formats
/COLLATING_SEQUENCE=
(SEQUENCE=sequence_type
[,MODIFICATION=(character operator character)]
[,IGNORE=character or character-range,...]
[,FOLD]
[,[NO]TIE_BREAK])
SEQUENCE=sequence_type
ASCII
Specifies ASCII collating sequence, which is the default
sequence.
EBCDIC
Arranges characters according to EBCDIC sequence. The characters
remain in ASCII representation; only the order is changed.
MULTINATIONAL
Arranges characters according to Multinational sequence, which
collates the international character set. When you use the
Multinational sequence, characters are ordered according to the
following rules:
o All diacritical forms of a character are given the collating
value of the character (A',A",A` collate as A).
o Lowercase characters are given the collating value of their
uppercase equivalents (a collates as A, a" collates as A").
o If two strings compare as equal, tie-breaking is performed.
The strings are compared to detect differences due to
diacritical marks, ignored characters, or characters that
collate as equal although they are actually different. If the
strings still compare as equal, another comparison is done
based on the numeric codes of the characters. In this final
comparison, lowercase characters are ordered before uppercase.
Care should be taken when sorting or merging files for further
processing using the Multinational sequence. Sequence checking
procedures in most programming languages compare numeric
characters. Because Multinational is based on actual graphic
characters and not on the codes representing those characters,
normal sequence checking does not work.
user-defined-sequence
Specifies a user-defined collating sequence. Define a collating
sequence by specifying a string of single or double characters
or ranges of single characters. (A double character is any set
of two single characters collated as if they were one character.
For example, "CH" can be defined to collate as "C".) This string
should be enclosed in parentheses.
You can also represent characters by their corresponding octal,
decimal, or hexadecimal values using the radix operators: %O, %D,
%X.
You must observe the following rules when defining your collating
sequence:
o Enclose characters in quotation marks (" ").
o Separate each character and character range with a comma, and
enclose the entire list in parentheses.
o Give all the characters appearing in the character keys in
the sort or merge operation a collating value. Any character
not given a collating value will be ignored unless the FOLD or
MODIFICATION options are specified.
o Do not define a character more than once.
o Do not specify the null character by using quotation marks
(""). Instead, use a radix operator such as %X0.
o Specify quotation marks by enclosing them within another set
of quotation marks ("" "") or by using a radix operator.
MODIFICATION=(character operator character)
Specifies a change to the collating sequence specified in the
SEQUENCE option. You can modify the ASCII, EBCDIC, Multinational,
or user-defined sequence. The sequence being modified must be
specified with the SEQUENCE qualifier even if the sequence is the
default (ASCII).
character
Specifies a character in the collating sequence. You can specify
a single or double character. A double character is any set
of two single characters collated as if they were a single
character. Enclose the character in quotation marks.
operator
Specifies the operator used to compare the characters. You can
specify greater than (>), less than (<), or equal to (=).
These are the kinds of changes permitted in the MODIFICATION
option:
o A single or double character can be equated to a single
character that has already been assigned a collating value
("a"="A").
o A single or double character can collate after a single
character that has already been assigned a collating value
("CH">"C").
o A single or double character can collate before a single
character that has already been assigned a collating value
("D"<"A").
o A double character can be equated to a previously defined
double character ("CH" = "SH").
o A single character can be equated to a double character
sequence ("C" = "CH").
IGNORE
Specifies that Sort/Merge ignore a character or character range
in the collating sequence when making an initial comparison.
Note that, when tie-breaking takes place, Sort/Merge considers
the characters specified with the IGNORE qualifier. Tie-breaking
takes place when two or more strings have compared as equal and
the Multinational sequence is being used or when two or more
strings have compared as equal and the TIE_BREAK qualifier has
been specified.
FOLD
Specifies that all lowercase letters be given the collating value
of their uppercase equivalents. For ASCII, EBCDIC, and user-
defined sequences, the lowercase letters are a to z.
Because the lowercase letters in the Multinational sequence
already have the collating value of their uppercase equivalents,
using FOLD is unnecessary.
TIE_BREAK
Specifies whether or not Sort/Merge should use numeric values to
break any ties between characters that have equivalent values.
By default, tie-breaking occurs with the Multinational sequence.
Specifying NOTIE_BREAK overrides this default and ensures that no
further comparisons are made after the initial comparison.
A TIE_BREAK option must be specified for the ASCII, EBCDIC, and
user-defined sequences in order for tie-breaking to occur. TIE_
BREAK should be used when specifying FOLD or MODIFICATION for the
these sequences.
The MODIFICATION, IGNORE, FOLD, and [NO]TIE_BREAK options of
the /COLLATING_SEQUENCE qualifier can also be used to modify the
collating sequence. You can make more than one modification to
the collating sequence. If you intend to modify any collating
sequence, you must specify the sequence in the SEQUENCE option,
even if it is the default sequence (ASCII).
Because the FOLD, MODIFICATION, and IGNORE qualifiers are
processed in the order in which they are specified, care should
be taken when specifying the order of those qualifiers. Normally,
FOLD should be specified after all MODIFICATION and IGNORE
qualifiers to ensure that the effects of the MODIFICATION and
IGNORE qualifiers apply to uppercase and lowercase characters.
You can request that Sort/Merge ignore a character or character
range within the given collating sequence by using the IGNORE
qualifier.
By default, in the Multinational collating sequence, Sort/Merge
folds lowercase letters into their uppercase equivalents. If
you want this folding to occur in the other collating sequences,
you must specify a FOLD qualifier with the instructions for the
collating sequence.
Also, by default in the Multinational collating sequence,
Sort/Merge uses numeric comparisons to break any ties in the
collating values. Ties occur when two equal keys collate the
same. If you do not want the default when using the Multinational
collating sequence, specify the keyword NOTIE_BREAK. For tie
breaking in the other collating sequences, specify a TIE_BREAK
qualifier.
1./COLLATING_SEQUENCE=(SEQUENCE=ASCII,IGNORE=("-"," "))
This /COLLATING_SEQUENCE qualifier with an IGNORE option
specified results in the following fields being compared as
equal before tie breaking:
252-3412
252 3412
2523412
2./COLLATING_SEQUENCE=(SEQUENCE=("A"-"L","LL","M"-"R","RR","S"-"Z"))
This /COLLATING_SEQUENCE qualifier defines a sequence in
which the double character LL collates as a single character
between L and M, and the double character RR collates as a
single character between R and S. These double characters
would otherwise appear in their usual alphabetical order. By
default, this user-defined sequence does not define any other
characters, such as lowercase a to z.
3./COLLATING_SEQUENCE=(SEQUENCE=
("AN","EB","AR","PR","AY","UN","UL",
"UG","EP","CT","OV","EC","0"-"9"),
MODIFICATION=("'"="19"),
FOLD)
This /COLLATING_SEQUENCE qualifier defines a collating
sequence. It includes a user-defined sequence that gives each
month a unique value in chronological order. For example, if
you want to order a file called SEMINAR.DAT according to the
date, the file SEMINAR.DAT would be set up as follows:
16 NOV 1983 Communication Skills
05 APR 1984 Coping with Alcoholism
11 Jan '84 How to Be Assertive
12 OCT 1983 Improving Productivity
15 MAR 1984 Living with Your Teenager
08 FEB 1984 Single Parenting
07 Dec '83 Stress --- Causes and Cures
14 SEP 1983 Time Management
The primary key is the year field; the secondary key is the
month field. Because the month field is not numeric and you
want the months ordered chronologically, you must define
your own collating sequence. You can do this by sorting on
the second two letters of each month-in their chronological
sequence-giving each month a unique key value.
The MODIFICATION option specifies that the apostrophe (') be
equated to 19, thereby allowing a comparison of '83 and 1984.
The FOLD option specifies that uppercase and lowercase letters
are treated as equal.
The output from this sort operation appears as follows:
14 SEP 1983 Time Management
12 OCT 1983 Improving Productivity
16 NOV 1983 Communication Skills
07 Dec '83 Stress --- Causes and Cures
11 Jan '84 How to Be Assertive
08 FEB 1984 Single Parenting
15 MAR 1984 Living with Your Teenager
05 APR 1984 Coping with Alcoholism
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