https://github.com/asardaes/table.express

Use dplyr verbs to build data.table expressions
https://github.com/asardaes/table.express

Last synced: 5 months ago
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Use dplyr verbs to build data.table expressions

• Host: GitHub
• URL: https://github.com/asardaes/table.express
• Owner: asardaes
• License: mpl-2.0
• Created: 2019-05-06T06:21:17.000Z (almost 6 years ago)
• Default Branch: master
• Last Pushed: 2023-04-04T10:44:01.000Z (about 2 years ago)
• Last Synced: 2024-11-13T14:54:13.452Z (5 months ago)
• Language: R
• Homepage: https://asardaes.github.io/table.express/
• Size: 907 KB
• Stars: 65
• Watchers: 3
• Forks: 5
• Open Issues: 2
• Metadata Files:
  • Readme: README.Rmd
  • Changelog: NEWS.md
  • License: LICENSE

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• jimsghstars - asardaes/table.express - Use dplyr verbs to build data.table expressions (R)

README

        
---

output:

    md_document:

        variant: gfm

editor_options: 

  chunk_output_type: console

---

```{r setup, cache = FALSE, include = FALSE}

library(knitr)

library(data.table)

library(table.express)

knitr::opts_chunk$set(

    collapse = TRUE,

    comment = "#>",

    fig.path = "README-",

    cache = FALSE

)

```

[![CRAN\_Status\_Badge](http://www.r-pkg.org/badges/version/table.express)](https://cran.r-project.org/package=table.express)

[![R-CMD-check](https://github.com/asardaes/table.express/workflows/R-CMD-check/badge.svg)](https://github.com/asardaes/table.express/actions)

[![codecov](https://codecov.io/gh/asardaes/table.express/branch/master/graph/badge.svg)](https://codecov.io/gh/asardaes/table.express)

# Table express

Use `dplyr` verbs, as well as custom ones, to build `data.table` expressions.

Check the [vignette](https://asardaes.github.io/table.express/articles/table.express.html) for more information.

## Essence

The basic idea is to parse the input from all the verbs and create a single expression that, after evaluation,

simply delegates all the actual computations to `data.table`,

letting it handle all optimizations as usual.

```{r essence}

# the expression is what matters here, input is left empty

data.table() %>%

    start_expr %>%

    select(col) %>%

    where(var == val) %>%

    order_by(v)

```

The input `data.table` is always assigned in the evaluation's environment as the `.DT_` pronoun

In many cases character input can also be supported,

which could be useful for other packages that use `data.table`.

## License

[Mozilla Public License Version 2.0](LICENSE)

This software package was developed independently of any organization or institution that is or has been associated with the author.