Laine at 19:22, 11 June 2007

Laine — Mon, 11 Jun 2007 19:22:31 GMT

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==Files==
/def/descriptor/case_pattern.c
/lib/descriptors/case_pattern.h

==Description==

Case pattern descriptors implement a mechanism that allows you to abstract
the pattern of upper and lower case letters from a string, manipulate it in
lower-case, and then restore the original case pattern when you are done.
The way this usually goes is like so:

#include <case_pattern.h>

string text = get_some_text();
descriptor pat = Case_Pattern_Extract(&text);
text = transform_the_text_in_various_ways(text);
text = Case_Pattern_Restore(text, pat);

Note that the argument to Case_Pattern_Extract() is being passed by
reference. This causes it to be converted to lower-case. You do not have
to pass the argument by reference if you do not want it to be converted to
lower-case.

This is usually all you need to know about the mechanism; the fields of
the descriptor and so forth are all managed internally. The remainder of
this document is provided for reference purposes.

===Public Fields===

Case_Pattern_Type: The type of the case pattern. This is one of the
following:

Case_Pattern_Type_Indeterminate: No representable case pattern was
found in the original text. This generally means the original text
contained no letters.

Case_Pattern_Type_All_Upper: All letters in the original text were
upper-case.

Case_Pattern_Type_All_Lower: All letters in the original text were
lower-case.

Case_Pattern_Type_First_Upper: The first letter in the original text
was upper-case and the remainder were lower-case.

Case_Pattern_Type_First_Lower: The first letter in the original text
was lower-case and the remainder were upper-case.

Case_Pattern_Type_Words_Upper: The original text had a capital letter
at the beginning of each word, as if it were the output of the call
capitalize_words(some_text).

Case_Pattern_Type_Main_Words_Upper: The original text had a capital
letter at the beginning of each word, as if it were the output of the
call capitalize_words(some_text, True).

Case_Pattern_Type_Complex: The original text had a complex case
pattern, as specified in the Case_Pattern_Content field.

Case_Pattern_Original: The original text the case pattern is based on.

Case_Pattern_Altered: The text with the case pattern extracted (converted
to lower-case).

Case_Pattern_Content: For Case_Pattern_Type_Complex patterns, an array
describing the case pattern in the original text. Each element will be
either Case_Pattern_Element_Upper, Case_Pattern_Element_Lower, or
Case_Pattern_Neither, corresponding to one letter in the original text.

===Internal Fields===

Case_Pattern_Tag: The tag value for the descriptor system.

===Support Functions===

'''descriptor Case_Pattern_Extract(string text)'''

Extracts the case pattern from the specified text and returns it. If
the text is passed by reference, it will be converted to lower-case.

'''string Case_Pattern_Restore(string text, descriptor dxr)'''

Coerces the specified text into the case pattern described by the
descriptor passed and returns the result.

==See Also==
[[man lower case|lower_case(efun)]], [[man upper case|upper_case(efun)]], [[man capitalize|capitalize(efun)]], [[man capitalize words|capitalize_words(sefun)]], [[man descriptors|descriptors(mechanisms)]]

Man case pattern - Revision history

Laine at 19:22, 11 June 2007