| Title: | List Comprehensions |
|---|---|
| Description: | An implementation of list comprehensions as purely syntactic sugar with a minor runtime overhead. It constructs nested for-loops and executes the byte-compiled loops to collect the results. |
| Authors: | Dirk Schumacher [aut, cre, cph] |
| Maintainer: | Dirk Schumacher <[email protected]> |
| License: | MIT + file LICENSE |
| Version: | 0.4.1.9000 |
| Built: | 2024-11-18 03:08:02 UTC |
| Source: | https://github.com/dirkschumacher/listcomp |
Create lists of elements using an expressive syntax. Internally nested for-loops are created and compiled that generate the list.
gen_list(element_expr, ..., .compile = TRUE, .env = parent.frame())gen_list(element_expr, ..., .compile = TRUE, .env = parent.frame())
element_expr |
an expression that will be collected |
... |
either a logical expression that returns a length 1 result. A named list of equal length sequences that are iterated over in parallel or a named parameter with an iterable sequence. |
.compile |
compile the resulting for loop to bytecode befor eval |
.env |
the parent environment in which all the elements are being evaluated. |
For parallel iterations all elements in the list need to be of
equal length. This is not checked at runtime at the moment.
A list of all generated values. The element-type is determined by the
parameter element_expr.
gen_list(c(x, y), x = 1:10, y = 1:10, x + y == 10, x < y) z <- 10 gen_list(c(x, y), x = 1:10, y = 1:10, x + y == !!z, x < y) # it is also possible to iterate in parallel by passing a list of # sequences gen_list(c(x, y), list(x = 1:10, y = 1:10), (x + y) %in% c(4, 6))gen_list(c(x, y), x = 1:10, y = 1:10, x + y == 10, x < y) z <- 10 gen_list(c(x, y), x = 1:10, y = 1:10, x + y == !!z, x < y) # it is also possible to iterate in parallel by passing a list of # sequences gen_list(c(x, y), list(x = 1:10, y = 1:10), (x + y) %in% c(4, 6))