The goal of postlogic is to allow natural flowing logic statements.
You can install the released version of postlogic from CRAN with:
install.packages("postlogic")
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.
<- TRUE
verbose message("Hello there") %if% verbose
#> Hello there
When combined with the %otherwise%
statement it allows
for an alternate.
<- "calm"
mood message("How dare you!") %if% (mood == 'angry') %otherwise%
message("Everything is fine.")
#> Everything is fine.
<- 'angry'
mood message("How dare you!") %if% (mood == 'angry') %otherwise%
message("Everything is fine.")
#> How dare you!
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%
.
<- 'calm'
mood 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.
The postlogic
package is developed by the R
Documentation Task Force, an R
Consortium Infrastructure
Steering Committee working group.