postlogic
Infix and Postfix Logic Operators
Provides adds postfix and infix logic operators for if, then, unless, and otherwise.
postlogic
The goal of postlogic is to allow natural flowing logic statements.
Installation
You can install the released version of postlogic from CRAN with:
install.packages("postlogic")
If/Otherwise
The if/otherwise instruction allows for simple logic to follow a statement to make it conditional. The %if% can be used alone to make an action conditional.
verbose <- TRUEmessage("Hello there") %if% verbose
When combined with the %otherwise% statement it allows for an alternate.
mood <- "calm"message("How dare you!") %if% (mood == 'angry') %otherwise%message("Everything is fine.")#> Everything is fine.mood <- 'angry'message("How dare you!") %if% (mood == 'angry') %otherwise%message("Everything is fine.")#> How dare you!
Unless/Then
The %unless% operator is essentially the negation of %if%. So when a statement is postfixed by an %unless% statement it will happen unless the proposition returns TRUE. The alternating operator for %unless% is %then%.
mood <- 'calm'message("Everything is fine.") %unless% (mood == 'angry') %then%message("How dare you!")#> Everything is fine.
This example is the same effect as the statements in the previous example.
Documentation
The postlogic package is developed by the R Documentation Task Force, an R Consortium Infrastructure Steering Committee working group.