https://github.com/nacnudus/lexl
An R package to tokenise Excel formulas
https://github.com/nacnudus/lexl
Last synced: about 2 months ago
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An R package to tokenise Excel formulas
- Host: GitHub
- URL: https://github.com/nacnudus/lexl
- Owner: nacnudus
- License: other
- Created: 2017-09-17T20:47:41.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2017-10-10T18:03:14.000Z (over 7 years ago)
- Last Synced: 2025-01-05T18:26:54.453Z (3 months ago)
- Language: R
- Homepage: https://nacnudus.github.com/lexl
- Size: 466 KB
- Stars: 4
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.Rmd
- License: LICENSE
Awesome Lists containing this project
- jimsghstars - nacnudus/lexl - An R package to tokenise Excel formulas (R)
README
---
output: github_document
---
```{r setup, include = FALSE}
knitr::opts_chunk$set(
collapse = TRUE,
comment = "#>",
fig.path = "man/figures/README-"
)
```
# lexl
[](https://travis-ci.org/nacnudus/lexl)
[](https://ci.appveyor.com/project/nacnudus/lexl)
[](https://cran.r-project.org/package=lexl)
[](https://www.r-pkg.org/pkg/lexl)
[](https://codecov.io/github/nacnudus/lexl?branch=master)
[lexl](https://github.com/nacnudus/lexl) separates Excel formulas into tokens of
different types, and gives their depth within a nested formula. Its name is a
bad pun on 'Excel' and 'lexer'. Try the [online
demo](https://duncan-garmonsway.shinyapps.io/lexl/) or run `demo_lexl()`
locally.
## Installation
You can install lexl from github with:
```{r gh-installation, eval = FALSE}
# install.packages("devtools")
devtools::install_github("nacnudus/lexl")
```
## Example
```{r, fig.width = 7, fig.height = 5}
library(lexl)
x <- lex_xl("MIN(3,MAX(2,A1))")
x
plot(x) # Requires the ggraph package
```
## Parse tree
Not all parse trees are the same. The one given by `lex_xl()` is intended for
analysis, rather than for computation. Examples of the kind of analysis that it
might support are:
* Detecting constants that have been embedded inside formulas, rather than in
cells referred to by formulas.
* Revealing which functions and combinations of functions are most common.
* Untangling the dependencies between cells in a spreadsheet.
## Where to find specimen formulas
The [tidyxl](https://nacnudus.github.io/tidyxl) package imports formulas from
xlsx (spreadsheet) files.
The [Enron
corpus](https://figshare.com/articles/Enron_Spreadsheets_and_Emails/1221767)
contains thousands of real-life spreadsheets.
## Inspiration
[Research](https://drive.google.com/file/d/0B79P2Uym3JjvMjlaWWtnTWRLQmc/view?usp=sharing)
by Felienne Hermans inspired this package, and the related
[XLParser](https://github.com/spreadsheetlab/XLParser) project was a great help
in creating the grammar.