string<? -- r7rs Definition

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Kind

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comparator;

Implemented by

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• string<? (from vonuvoli);

Procedure signature

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Procedure variants:

• ((string |2...|) -> (boolean))
  • inputs:
    • a value of type string;
    • ... -- at least 2 times;
  • output: a value of type boolean;

Exports

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• scheme:base -- (scheme base);

Exports recursive

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• scheme -- (scheme);

Description

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(string<? string_1 string_2 string_3 ...)
(string-ci<? string_1 string_2 string_3 ...)
(string>? string_1 string_2 string_3 ...)
(string-ci>? string_1 string_2 string_3 ...)
(string<=? string_1 string_2 string_3 ...)
(string-ci<=? string_1 string_2 string_3 ...)
(string>=? string_1 string_2 string_3 ...)
(string-ci>=? string_1 string_2 string_3 ...)

These procedures return #t if their arguments are (respectively): monotonically increasing, monotonically decreasing, monotonically non-decreasing, or monotonically non-increasing.

These predicates are required to be transitive.

These procedures compare strings in an implementation-defined way. One approach is to make them the lexicographic extensions to strings of the corresponding orderings on characters. In that case, string<? would be the lexicographic ordering on strings induced by the ordering char<? on characters, and if the two strings differ in length but are the same up to the length of the shorter string, the shorter string would be considered to be lexicographically less than the longer string. However, it is also permitted to use the natural ordering imposed by the implementation's internal representation of strings, or a more complex locale-specific ordering.

In all cases, a pair of strings must satisfy exactly one of string<?, string=?, and string>?, and must satisfy string<=? if and only if they do not satisfy string>? and string>=? if and only if they do not satisfy string<?.

The -ci procedures behave as if they applied string-foldcase to their arguments before invoking the corresponding procedures without -ci.

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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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• string;
• boolean;