[Fix #323] Implement coercion methods for Duration class

DESCRIPTION

@@ -36,6 +36,8 @@ Collate:
     'POSIXt.r'
     'util.r'
     'timespans.r'
+    'intervals.r'
+    'difftimes.r'
     'durations.r'
     'periods.r'
     'accessors-day.r'
@@ -51,8 +53,6 @@ Collate:
     'am-pm.r'
     'time-zones.r'
     'numeric.r'
-    'intervals.r'
-    'difftimes.r'
     'coercion.r'
     'constants.r'
     'data.r'

NAMESPACE

@@ -247,6 +247,7 @@ exportMethods("minute<-")
 exportMethods("month<-")
 exportMethods("second<-")
 exportMethods("year<-")
+exportMethods(Compare)
 exportMethods(as.character)
 exportMethods(as.difftime)
 exportMethods(as.interval)

R/durations.r

@@ -1,4 +1,5 @@
 #' @include timespans.r
+#' @include difftimes.r
 
 check_duration <- function(object){
 	if (is.numeric(object@.Data))
@@ -27,9 +28,6 @@ check_duration <- function(object){
 #' Durations class objects have one slot: .Data, a numeric object equal to the number 
 #' of seconds in the duration.
 #'
-#'
-#'
-#'
 #' @name Duration-class
 #' @rdname Duration-class
 #' @exportClass Duration
@@ -119,6 +117,27 @@ setMethod("[[<-", signature(x = "Duration"),
 })
 
 
+#' @export
+setMethod("Compare", c(e1 = "Duration", e2 = "ANY"),
+          function(e1, e2){
+            stop(sprintf("Incompatible duration classes (%s, %s). Please coerce with `as.duration`.",
+                         class(e1), class(e2)),
+                 call. = FALSE)
+          })
+
+#' @export
+setMethod("Compare", c(e1 = "difftime", e2 = "Duration"),
+          function(e1, e2){
+            callGeneric(as.numeric(e1, "secs"),
+                        as.numeric(e2, "secs"))
+          })
+
+#' @export
+setMethod("Compare", c(e1 = "Duration", e2 = "Duration"),
+          function(e1, e2){
+            callGeneric(e1@.Data, e2@.Data)
+          })
+
 
 #' Create a duration object.
 #'

tests/testthat/test-durations.R

@@ -189,3 +189,20 @@ test_that("as.duration handles NA objects", {
   na.dur <- dseconds(NA)
   expect_equal(as.duration(NA), na.dur)
 })
+
+
+test_that("Comparison operators work duration and difftime objects (#323)", {
+  t1 <- now()
+  t2 <- t1 + dhours(1)
+  t3 <- t1 + dseconds(1)
+
+  expect_true((t2 - t1) >  dseconds(60))
+  expect_false((t2 - t1) >  dseconds(3600))
+  expect_true((t2 - t1) < dseconds(3601))
+
+  expect_true(dhours(1) > dminutes(59))
+  expect_true(dhours(1) == dseconds(3600))
+
+  expect_error(dhours(1) == 3600)
+  expect_error(dhours(1) == 1)
+})

tests/testthat/test-ops-division.R

@@ -133,7 +133,7 @@ test_that("division operations work for difftime numerator",{
 
   expect_error(diff/int)
   expect_error(diff/days(1))
-  expect_equal(diff/ ddays(365), 1)
+  expect_equal(diff/ddays(365), 1)
 
 })