char-upcase -- r7rs Definition

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Kind

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procedure;

Implemented by

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• char-upcase (from vonuvoli);

Procedure signature

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Procedure variants:

• ((character-ascii) -> (character-ascii))
  • input: a value of type character-ascii;
  • output: a value of type character-ascii;
• ((character) -> (character))
  • input: a value of type character;
  • output: a value of type character;

Exports

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• scheme:char -- (scheme char);

Exports recursive

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• scheme -- (scheme);

Description

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(char-upcase char)
(char-downcase char)
(char-foldcase char)

The char-upcase procedure, given an argument that is the lowercase part of a Unicode casing pair, returns the uppercase member of the pair, provided that both characters are supported by the Scheme implementation. Note that language-sensitive casing pairs are not used. If the argument is not the lowercase member of such a pair, it is returned.

The char-downcase procedure, given an argument that is the uppercase part of a Unicode casing pair, returns the lowercase member of the pair, provided that both characters are supported by the Scheme implementation. Note that language-sensitive casing pairs are not used. If the argument is not the uppercase member of such a pair, it is returned.

The char-foldcase procedure applies the Unicode simple case-folding algorithm to its argument and returns the result. Note that language-sensitive folding is not used. If the argument is an uppercase letter, the result will be either a lowercase letter or the same as the argument if the lowercase letter does not exist or is not supported by the implementation. See UAX #29 (part of the Unicode Standard) for details.

Note that many Unicode lowercase characters do not have uppercase equivalents.

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The text herein was sourced and adapted as described in the "R7RS attribution of various text snippets" appendix.

Referenced-types

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• character-ascii;
• character;