search for: eval2

Displaying 2 results from an estimated 2 matches for "eval2".

Did you mean: val2
2015 Feb 09
1
WISH: eval() to preserve the "visibility" (now value is always visible)
...evaluated first. So, eval(x <- 2) is effectively like { x <- 2; eval(2) } , which is effectively { x <- 2; 2 } . The result is visible. eval(expression(x <- 2)) or eval(quote(x <- 2)) or evalq(x <- 2) gives the same effect as x <- 2 . The result is invisible. In function 'eval2', res <- eval(withVisible(expr), envir=envir, ...) is effectively res <- withVisible(expr) . ------------------- Would it be possible to have the value of eval() preserve the "visibility" of the value of the expression? "PROBLEM": # Invisible > x <- 1 # Vis...
2015 Feb 07
1
WISH: eval() to preserve the "visibility" (now value is always visible)
...y" of the value of the expression? "PROBLEM": # Invisible > x <- 1 # Visible > eval(x <- 2) [1] 2 "TROUBLESHOOTING": > withVisible(x <- 1) $value [1] 1 $visible [1] FALSE > withVisible(eval(x <- 2)) $value [1] 2 $visible [1] TRUE WORKAROUND: eval2 <- function(expr, envir=parent.frame(), ...) { res <- eval(withVisible(expr), envir=envir, ...) value <- res$value if (res$visible) value else invisible(value) } > x <- 1 > eval(x <- 2) [1] 2 > eval2(x <- 3) > x [1] 3 /Henrik