Further updates.

R/scalars.R

@@ -29,3 +29,6 @@ val_rm <- function(x, value){
     sset(x, cpp_which_val(x, value, invert = TRUE))
   }
 }
+which_val <- function(x, value, invert = FALSE){
+  .Call(`_cheapr_cpp_which_val`, x, value, invert)
+}

R/sset.R

@@ -67,6 +67,7 @@ sset <- function(x, ...){
 #' @export
 sset.default <- function(x, i, ...){
   if (!missing(i) && is.logical(i)){
+    check_length(i, length(x))
     i <- which_(i)
   }
   # The below line will handle a special but common
@@ -105,6 +106,7 @@ sset.Date <- function(x, i, ...){
   # out <- sset.default(unclass(x), i, ...)
   # set_attr(out, "class", oldClass(x))
   if (!missing(i) && is.logical(i)){
+    check_length(i, length(x))
     i <- which_(i)
   }
   if (!missing(i) &&
@@ -127,6 +129,7 @@ sset.Date <- function(x, i, ...){
 #' @export
 sset.POSIXct <- function(x, i, ...){
   if (!missing(i) && is.logical(i)){
+    check_length(i, length(x))
     i <- which_(i)
   }
   if (!missing(i) &&
@@ -149,6 +152,7 @@ sset.POSIXct <- function(x, i, ...){
 #' @export
 sset.factor <- function(x, i, ...){
   if (!missing(i) && is.logical(i)){
+    check_length(i, length(x))
     i <- which_(i)
   }
   if (!missing(i) &&

README.Rmd

@@ -166,6 +166,28 @@ mark(sset(df, -10^4:0),
      check = FALSE) # The only difference is the row names
 ```
 
+The biggest difference between `sset` and `[` is the way logical vectors are handled.
+The two main differences when `i` is a logical vector are:
+
+* `NA` values are ignored, only the locations of `TRUE` values are used.
+* `i` must be the same length as `x` and is not recycled.
+
+
+```{r,error=TRUE}
+# Examples with NAs
+x <- c(1, 5, NA, NA, -5)
+x[x > 0]
+sset(x, x > 0)
+
+# Example with length(i) < length(x)
+sset(x, TRUE)
+
+# This is equivalent 
+x[TRUE]
+# to..
+sset(x)
+```
+
 
 ## Greatest common divisor and smallest common multiple