Capture interrupts and error

Fixes #314

NEWS.md

@@ -30,6 +30,10 @@ There have also been two changes to eliminate name conflicts between purrr and d
   refer to arguments by position with `..1`, `..2`, and so on. This makes it 
   possible to use the formula shorthand for functions with more than two 
   arguments (#289).
+
+* `possibly()`, `safely()` and friends no longer capture interrupts: this 
+  means that you can now terminate a mapper using one of these with
+  Escape or Ctrl + C (#314)
 
 ## Map functions
 

R/output.R

@@ -82,6 +82,9 @@ possibly <- function(.f, otherwise, quiet = TRUE) {
         if (!quiet)
           message("Error: ", e$message)
         otherwise
+      },
+      interrupt = function(e) {
+        stop("Terminated by user", call. = FALSE)
       }
     )
   }
@@ -109,6 +112,9 @@ auto_browse <- function(.f) {
           frame <- ctxt_frame(7)
           browse_in_frame(frame)
         }
+      },
+      interrupt = function(e) {
+        stop("Terminated by user", call. = FALSE)
       }
     )
   }
@@ -135,6 +141,9 @@ capture_error <- function(code, otherwise = NULL, quiet = TRUE) {
         message("Error: ", e$message)
 
       list(result = otherwise, error = e)
+    },
+    interrupt = function(e) {
+      stop("Terminated by user", call. = FALSE)
     }
   )
 }