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A set of predicates and assertions for checking the properties of strings. Most of the documentation is on the assertive page. End-users will usually want to use assertive directly.


To install the stable version, type:


To install the development version, you first need the devtools package.


Then you can install the assertive.strings package using



is_empty_character, is_non_empty_character, is_missing_or_empty_character, and is_non_missing_nor_empty_character check for empty and missing (or not) character vectors.

is_an_empty_string, is_a_non_empty_string, is_a_missing_or_empty_string, and is_a_non_missing_nor_empty_string do the same, for single strings.

is_numeric_string checks for strings that contain numbers.

is_single_character checks for single characters.

is_matching_fixed, is_matching_regex, is_not_matching_fixed, and is_not_matching_regex all check whether a string matches a pattern or not.


Predicates that return a vector have two corresponding assertions. For example, is_numeric_string has assert_all_are_numeric_strings and assert_any_are_numeric_strings.

Predicates returning a single logical value have one corresponding assertion. For example, is_an_empty_string has assert_is_an_empty_string.


character_to_list_of_integer_vectors converts a character vector of numbers to a list of integer vectors.