Archive/README 2020-08-08.md

In robertschnitman/stringops: String Operations

stringops: String-processing Tools for R

When creating syntax, one has to ask themselves about the naming scheme: should I make the functions short for typing efficiency, or long for increased readability? Ruby has the former benefit, but sometimes the methods can be difficult to remember (e.g. is it len or length? Is it swapcase or swap_case?), as there isn’t a consistent naming scheme–however, some functions have synonyms to help those from other programming languages learn Ruby faster (e.g. reduce and inject do the same thing). On the other hand, the stringr library has a consisent naming scheme for its functions, but does not have synonyms, so you are forced to learn the stringr way. Thirdly, and perhaps tagentially, R does not have concatenation operator (only functions) like in Ruby and BASIC, which is odd, as many situations require concatenation; so using the paste/paste0() functions can make code less readable. As such, I am introducing a new package to take these considerations into account: stringops, a work-in-progress library consisting of tools for processing strings in R.

What this package brings are (1) a consistent naming-scheme for functions, (2) synonyms for said functions, and (3) a concatenation operator. The first item benefits users of all skill levels, as it makes certain functions easier to remember while making use of RStudio’s predictive text. The second item is useful when one tires of typing string_cull(), for example, and wishes to use a shorthand to simplify the code (in this case, the shorthand would be cull()). The third item’s benefit is more readable code by avoiding the function syntax of paste/paste0(). Ultimately, these items will hopefully make processing strings in R more fun for the user!

The following sections detail the installation procedure and a sample of functions from this package. Please see the Gitbook for more information.

Installation

This package currently is only available on GitHub–there are no plans to submit this package to CRAN at this time. As such, please use the devtools library to install stringops.

# install.packages('devtools')

devtools::install_github('robertschnitman/stringops')

library(stringops)

## 
## Attaching package: 'stringops'

## The following object is masked from 'package:utils':
## 
##     find

%&%

As inspired by AutoIt, the %&% (concatenation) operator joins two strings together. This operator facilitates readable code by avoiding the function syntax of the paste/paste0().

'a' %&% 'b'

## [1] "ab"

"Car: " %&% rownames(mtcars)

##  [1] "Car: Mazda RX4"           "Car: Mazda RX4 Wag"      
##  [3] "Car: Datsun 710"          "Car: Hornet 4 Drive"     
##  [5] "Car: Hornet Sportabout"   "Car: Valiant"            
##  [7] "Car: Duster 360"          "Car: Merc 240D"          
##  [9] "Car: Merc 230"            "Car: Merc 280"           
## [11] "Car: Merc 280C"           "Car: Merc 450SE"         
## [13] "Car: Merc 450SL"          "Car: Merc 450SLC"        
## [15] "Car: Cadillac Fleetwood"  "Car: Lincoln Continental"
## [17] "Car: Chrysler Imperial"   "Car: Fiat 128"           
## [19] "Car: Honda Civic"         "Car: Toyota Corolla"     
## [21] "Car: Toyota Corona"       "Car: Dodge Challenger"   
## [23] "Car: AMC Javelin"         "Car: Camaro Z28"         
## [25] "Car: Pontiac Firebird"    "Car: Fiat X1-9"          
## [27] "Car: Porsche 914-2"       "Car: Lotus Europa"       
## [29] "Car: Ford Pantera L"      "Car: Ferrari Dino"       
## [31] "Car: Maserati Bora"       "Car: Volvo 142E"

string_cull()

As inspired by Ruby, the function string_cull() culls (or extracts) pattern matches from strings–if a pattern is not found, then NA is returned. The synonyms for this function are s_cull(), cull(), string_extract(), s_extract(), and extract().

# extract beginning "M" from each element.
string_cull(rownames(mtcars), '^M')

##  [1] "M" "M" NA  NA  NA  NA  NA  "M" "M" "M" "M" "M" "M" "M" NA  NA  NA  NA  NA 
## [20] NA  NA  NA  NA  NA  NA  NA  NA  NA  NA  NA  "M" NA

# extract elements in full that begin with "M".
string_cull(rownames(mtcars), "^M.*")

##  [1] "Mazda RX4"     "Mazda RX4 Wag" NA              NA             
##  [5] NA              NA              NA              "Merc 240D"    
##  [9] "Merc 230"      "Merc 280"      "Merc 280C"     "Merc 450SE"   
## [13] "Merc 450SL"    "Merc 450SLC"   NA              NA             
## [17] NA              NA              NA              NA             
## [21] NA              NA              NA              NA             
## [25] NA              NA              NA              NA             
## [29] NA              NA              "Maserati Bora" NA

string_find()

The function string_find() acts similar to grep(string, x, value = TRUE): it subsets a vector to found pattern matches, returning the full element. The synonyms for this function are s_find(), and find().

string_find(rownames(mtcars), '^M')

##  [1] "Mazda RX4"     "Mazda RX4 Wag" "Merc 240D"     "Merc 230"     
##  [5] "Merc 280"      "Merc 280C"     "Merc 450SE"    "Merc 450SL"   
##  [9] "Merc 450SLC"   "Maserati Bora"

robertschnitman/stringops documentation built on Aug. 15, 2022, 3:46 p.m.