Game of Life using {coro} generators in R

game-of-life-coro-generators.R

# Game of Life using {coro} generators in R
# Inspiration from Jack Diederich's Python implementation: https://gist.github.com/jhrr/2b5a60e9efcb573c9cc4

library(tidyverse)
library(coro)
library(zeallot)

generate_neighbors <- generator(function(point) {
    c(x, y) %<-% point
    yield(c(x + 1, y))
    yield(c(x - 1, y))
    yield(c(x, y + 1))
    yield(c(x, y - 1))
    yield(c(x + 1, y + 1))
    yield(c(x + 1, y - 1))
    yield(c(x - 1, y + 1))
    yield(c(x - 1, y - 1))
})

recalculate <- \(board) {
    board %>% 
        map(generate_neighbors) %>% 
        map(collect) %>% 
        unlist(recursive = FALSE) %>% 
        union(board)
}

advance <- \(board){
    newstate <- list()
    for(point in recalculate(board)) {
        point_neighbors <- collect(generate_neighbors(point))
        count <- sum(point_neighbors %in% board)
        if (count == 3 || (count == 2 && (list(point) %in% board))) {
            newstate <- c(newstate, list(point))
        }
    }
    return(newstate)
}

glider <- list(c(0,0), c(1,0), c(2, 0), c(0,1), c(1,2))
for(i in 1:1000){
    glider <- advance(glider)
    print(paste0(i, " ", paste(glider, collapse = ", ")))
}
# [1] "1000 c(-249, -248), c(-249, -250), c(-250, -250), c(-248, -250), c(-250, -249)"


is_equivalent_set <- \(lst_x, lst_y) {
    ocurrences <- 
        lst_x |>
        sapply(\(x) {
            lst_y |> sapply(\(y) identical(sort(x), sort(y)))
        })
    return(all(rowSums(ocurrences) > 0) & all(colSums(ocurrences) > 0))
}
glider_p <- list(c(-249, -250), c(-248, -250), c(-250, -250), c(-249, -248), c(-250, -249))
is_equivalent_set(glider, glider_p)
# TRUE