Closes #1094. type.convert arg for tstrsplit.

R/transpose.R

@@ -10,6 +10,9 @@ transpose <- function(l, fill=NA, ignore.empty=FALSE) {
 	ans[]
 }
 
-tstrsplit <- function(..., fill=NA) {
-	transpose(strsplit(...), fill=fill, ignore.empty = FALSE)
+tstrsplit <- function(x, ..., fill=NA, type.convert=FALSE) {
+	ans = transpose(strsplit(as.character(x), ...), fill=fill, ignore.empty = FALSE)
+	# Implementing #1094, but default FALSE
+  if(type.convert) ans = lapply(ans, type.convert, as.is = TRUE)
+  ans
 }

README.md

@@ -36,6 +36,7 @@
     * `uniqueN` gains a `by` argument which is equal to `key(x)` when `x` is a `data.table` so that the behaviour is identical to `duplicated()` and and `unique` methods for `data.table`. Thanks to @kevinmistry for the report. Closes [#1080](https://github.com/Rdatatable/data.table/issues/1080).
 
   11. Implemented `transpose()` to transpose a list and `tstrsplit` which is a wrapper for `transpose(strsplit(...))`. This is particularly useful in scenarios where a column has to be split and the resulting list has to be assigned to multiple columns. See `?transpose` and `?tstrsplit`, [#1025](https://github.com/Rdatatable/data.table/issues/1025) and [#1026](https://github.com/Rdatatable/data.table/issues/1026) for usage scenarios. Closes both #1025 and #1026 issues.
+    * Implemented `type.convert` as suggested by Richard Scriven. Closes [#1094](https://github.com/Rdatatable/data.table/issues/1094).
 
   12. `melt.data.table` can now melt into multiple columns by providing a list of columns to `measure.vars` argument. Closes [#828](https://github.com/Rdatatable/data.table/issues/828). Thanks to Ananda Mahto for the extended email discussions and ideas on generating the `variable` column.
 

inst/tests/tests.Rraw

@@ -6256,6 +6256,15 @@ test(1505.1, as.matrix(dt), as.matrix(as.data.frame(dt)))
 dt = data.table(x=1, y=2)
 test(1506, setcolorder(dt, c("y", "x")), data.table(y=2, x=1))
 
+# tstrsplit, #1094
+# factor to character
+x = factor(paste(letters[1:5], letters[6:10], sep="-"))
+test(1507.1, tstrsplit(x, "-"), list(letters[1:5], letters[6:10]))
+# type.convert
+x = paste(letters[1:5], 1:5, sep="-")
+test(1507.2, tstrsplit(x, "-"), list(letters[1:5], as.character(1:5)))
+test(1507.3, tstrsplit(x, "-", type.convert=TRUE), list(letters[1:5], 1:5))
+
 ##########################