types-disjoint -- r7rs Category

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Description

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Disjointness of types

No object satisfies more than one of the following predicates:

boolean?          bytevector?
char?             eof-object?
null?             number?
pair?             port?
procedure?        string?
symbol?           vector?

and all predicates created by define-record-type.

These predicates define the types boolean, bytevector, character, the empty list object, eof-object, number, pair, port, procedure, string, symbol, vector, and all record types.

Although there is a separate boolean type, any Scheme value can be used as a boolean value for the purpose of a conditional test. As explained in section on booleans, all values count as true in such a test except for #f. This report uses the word true to refer to any Scheme value except #f, and the word false to refer to #f.

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

Types

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• boolean;
• number;
• symbol;
• character;
• string;
• bytevector;
• vector;
• null;
• pair;
• procedure;
• port;
• eof-object;

Super-categories

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• types;