Minimal list comprehensions in R, for fun.
Pass a Python-style list comprehension as a string to lc and have it
evaluated in the calling environment. Actual logic uses R syntax.
Supports nesting by wrapping inner comprehensions with [].
Can handle anything* of the form <R expression> for name in <R object> if <R expression>.
* Probably not anything
# install.packages("devtools")
# devtools::install_github("DexGroves/listcomp")
my_sequence <- seq(10)
nested_list <- list(seq(5), seq(10))
lc('item ^ 2 for item in my_sequence if item %% 2 == 0')
lc('x ^ 2 for x in [max(y) for y in nested_list]')
lc('j for i in seq(5) if i > 3 for j in seq(i)')Works just fine for anything that can be indexed, including data.frames.
library("ggplot2")
data(diamonds)
lc('mean(x) for x in diamonds if is.numeric(x)')
# carat depth table price x y z
# 0.7979397 61.7494049 57.4571839 3932.7997219 5.7311572 5.7345260 3.5387338