ensurer: ensurer - ensure values at runtime
In smbache/ensurer: Ensure values at runtime
Description
ensurer is a small utility package for R which provides a simple
and light-weight mechanism for ensuring certain aspects of values at runtime.
Details
R does not provide any mechanism for type-safety and since it is not
a compiled language, the risk of having unexpected results is there at
runtime. R functions often accept different types for the same input and/or
have different return types for different sitations.
As an example, a query to a database or the scraping of a website might
not return valid data, where "validity" can refer to a number of conditions.
It might a positive or certain number of records; that all cases are complete;
that some column is weekly increasing; or simply that the result is a
data.frame.
If one does not deal with these ambiguities and risks appropriately,
some resulting errors may be hard to track down. It is desirable to
get an error as soon as a value does not have the correct type or
does not satisfy certain criteria.
"Ensuring values" is here meant as a "contract", or a set of conditions,
such that if a value does not comply an error is raised instantly.
An ensuring contract (a function) is created with ensures_that
(ideal for multiple use or readability with complex contracts).
It is also possible to ensure properties on the fly using
ensure_that (ideal for simple, one-time contracts).
Using the magrittr pipe %>% greatly improves semantics of the
functionality provided by this package, but it is not necessary.
This package is not meant as a substitute for unit testing, and great
packages for this already exist, e.g. testthat by Hadley Wickham.
The ensurer package is meant as a simple and ideal tool for scripts or
programs where runtime conditions may break the functionality, and
where errors should be raised as soon and clear as possible.
For a more thorough introduction, see vignette(ensurer).
Author(s)
Stefan Holst Milton Bache <stefan@stefanbache.dk>
smbache/ensurer documentation built on May 30, 2019, 5:01 a.m.
R Package Documentation
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We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Description
ensurer is a small utility package for R which provides a simple and light-weight mechanism for ensuring certain aspects of values at runtime.
Details
R does not provide any mechanism for type-safety and since it is not a compiled language, the risk of having unexpected results is there at runtime. R functions often accept different types for the same input and/or have different return types for different sitations.
As an example, a query to a database or the scraping of a website might
not return valid data, where "validity" can refer to a number of conditions.
It might a positive or certain number of records; that all cases are complete;
that some column is weekly increasing; or simply that the result is a
data.frame.
If one does not deal with these ambiguities and risks appropriately, some resulting errors may be hard to track down. It is desirable to get an error as soon as a value does not have the correct type or does not satisfy certain criteria.
"Ensuring values" is here meant as a "contract", or a set of conditions,
such that if a value does not comply an error is raised instantly.
An ensuring contract (a function) is created with ensures_that
(ideal for multiple use or readability with complex contracts).
It is also possible to ensure properties on the fly using
ensure_that (ideal for simple, one-time contracts).
Using the magrittr pipe %>% greatly improves semantics of the
functionality provided by this package, but it is not necessary.
This package is not meant as a substitute for unit testing, and great
packages for this already exist, e.g. testthat by Hadley Wickham.
The ensurer package is meant as a simple and ideal tool for scripts or
programs where runtime conditions may break the functionality, and
where errors should be raised as soon and clear as possible.
For a more thorough introduction, see vignette(ensurer).
Author(s)
Stefan Holst Milton Bache <stefan@stefanbache.dk>
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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