remove range ambiguity and define istimespan

Project.toml

@@ -1,7 +1,7 @@
 name = "TimeSpans"
 uuid = "bb34ddd2-327f-4c4a-bfb0-c98fc494ece1"
 authors = ["Beacon Biosignals, Inc."]
-version = "0.1.0"
+version = "0.2.0"
 
 [deps]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"

src/TimeSpans.jl

@@ -42,14 +42,25 @@ TimeSpan(x) = TimeSpan(start(x), stop(x))
 ##### generic TimeSpans.jl interface
 #####
 
+"""
+    istimespan(x)
+
+Return `true` if `x` has been declared to support `TimeSpans.start(x)` and `TimeSpans.stop(x)`,
+return `false` otherwise.
+
+Types that overload `TimeSpans.start`/`TimeSpans.stop` should also overload `istimespan`.
+"""
+istimespan(::Any) = false
+istimespan(::TimeSpan) = true
+istimespan(::Period) = true
+
 """
     start(span)
 
 Return the inclusive lower bound of `span` as a `Nanosecond` value.
 """
 start(span::TimeSpan) = span.start
 start(t::Period) = convert(Nanosecond, t)
-start(r::AbstractRange) = convert(Nanosecond, first(r))
 
 """
     stop(span)
@@ -58,7 +69,6 @@ Return the exclusive upper bound of `span` as a `Nanosecond` value.
 """
 stop(span::TimeSpan) = span.stop
 stop(t::Period) = convert(Nanosecond, t) + Nanosecond(1)
-stop(r::AbstractRange) = convert(Nanosecond, last(r))
 
 #####
 ##### generic utilities

test/runtests.jl

@@ -13,6 +13,10 @@ using Test, TimeSpans, Dates
     @test TimeSpans.duration(TimeSpan(start(t), stop(t) + Nanosecond(100))) == Nanosecond(101)
     @test TimeSpans.duration(start(t)) == Nanosecond(1)
     @test_throws ArgumentError TimeSpan(4, 2)
+    @test TimeSpans.istimespan(t)
+    @test TimeSpans.istimespan(start(t))
+    @test !TimeSpans.istimespan(1)
+    @test !TimeSpans.istimespan(1:10)
 end
 
 @testset "contains(::TimeSpan...)" begin