agrueneberg / crochet

An implementation helper for [ and [<- for custom matrix-like types

crochet

crochet is an R package that provides functions to help implement the extraction / subsetting / indexing function [ and replacement function [<- of custom matrix-like types (based on S3, S4, etc.), modeled as closely to the base matrix class as possible (with tests to prove it).

Example

Check out the Example of a Custom Type that Implements 'extract' and 'replace' vignette on the crochet page on CRAN.

Installation

Install the stable version from CRAN:

install.packages("crochet")

Alternatively, install the development version from GitHub:

# install.packages("remotes")
remotes::install_github("agrueneberg/crochet")

Documentation

Further documentation can be found on RDocumentation.

Contributing

• Issue Tracker: https://github.com/agrueneberg/crochet/issues
• Source Code: https://github.com/agrueneberg/crochet

crochet's Issues

Handle NA subsetting

Some cases that could be handled by crochet itself:

• x[NA] for k
• x[NA, ] for i
• x[, NA] for j

I don't see any utility in developers implementing their own behavior for this case.

Detect ...

... needs to be counted againt nargs() to correctly detect index type.

Do not rely on matrix for CUSTOM_OBJECT in tests

Using matrix against matrix will not allow for the quirks of matrix subsetting to shine through in the tests.

Missing License File

Hi @agrueneberg

It would be helpful if the repository has a License File. It is showing as MIT expat in Description but it would be better if we had a clear Licence.md file

Handle character subsetting if dimnames are NULL

Need to expand test suite to test everything without dimnames.

Test additional arguments

Find a way to optionally test additional arguments, for example by specifying a name (CROCHET_EXTRACT_ENV$OPTIONAL_ARG_NAME), value (CROCHET_EXTRACT_ENV$OPTIONAL_ARG_VALUE), and expected outcome (CROCHET_EXTRACT_ENV$OPTIONAL_ARG_TRANSFORMATION).

Convert integers to doubles if .Machine$integer.max is reached

> pryr::sexp_type(.Machine$integer.max)
[1] "INTSXP"
> G[.Machine$integer.max]
[1] -0.002505102
> .Machine$integer.max + 1L
[1] NA
> pryr::sexp_type(.Machine$integer.max + 1)
[1] "REALSXP"
> G[.Machine$integer.max + 1]
Error: cannot allocate vector of size 1250.6 Gb
In addition: Warning message:
In convertIndex(x, i, "k") : NAs introduced by coercion to integer range

Implement independent simple matrix-like type for tests

Also see #4.

Handle FALSE subsetting

Some cases that could be handled by crochet itself:

• x[FALSE] for k
• x[FALSE, ] for i
• x[, FALSE] for j

I don't see any utility in developers implementing their own behavior for this case.