Drop v0.6 and update travis and add support to diff (#7)

* drop v0.6 and update to 1.0

* update travis

* add docs to module

* add diff

* use 0.7 & switch to recursive implementation

* add doc string

Author: Rogerluo

.travis.yml

@@ -4,7 +4,7 @@ os:
   - linux
   - osx
 julia:
-  - 0.6
+  - 0.7
   - nightly
 notifications:
   email: false

REQUIRE

@@ -1 +1 @@
-julia 0.6
+julia 1.0

src/TupleTools.jl

@@ -1,4 +1,6 @@
-__precompile__(true)
+"""
+Type stable methods for small tuples
+"""
 module TupleTools
 
 using Base: tuple_type_head, tuple_type_tail, tuple_type_cons, tail, front, setindex
@@ -26,12 +28,7 @@ Base.@pure StaticLength(N::Int) = StaticLength{N}()
 Base.@pure Base.:+(::StaticLength{N₁}, ::StaticLength{N₂}) where {N₁,N₂} = StaticLength(N₁+N₂)
 Base.@pure Base.:-(::StaticLength{N₁}, ::StaticLength{N₂}) where {N₁,N₂} = StaticLength(max(0,N₁-N₂))
 
-if VERSION < v"0.7.0-DEV.843"
-    @inline Base.ntuple(f, ::StaticLength{N}) where {N} = ntuple(f, Val{N})
-else
-    @inline Base.ntuple(f, ::StaticLength{N}) where {N} = ntuple(f, Val{N}())
-end
-
+@inline Base.ntuple(f, ::StaticLength{N}) where {N} = ntuple(f, Val{N}())
 @inline argtail2(a, b, c...) = c
 
 """
@@ -327,4 +324,13 @@ Inverse permutation of a permutation `p`.
 """
 invperm(p::Tuple{Vararg{Int}}) = sortperm(p)
 
+"""
+    diff(v::Tuple) -> Tuple
+
+Finite difference operator of tuple `v`.
+"""
+diff(v::Tuple{}) = () # similar to diff([])
+diff(v::Tuple{Any}) = ()
+diff(v::Tuple) = (v[2]-v[1], diff(Base.tail(v))...)
+
 end # module

test/runtests.jl

@@ -1,15 +1,4 @@
-if VERSION < v"0.7.0-DEV.2005"
-    const Test = Base.Test
-end
-if VERSION >= v"0.7.0-DEV.3406"
-    using Random
-end
-if VERSION < v"0.7.0-DEV.3516"
-    const argmin = Base.indmin
-    const argmax = Base.indmax
-end
-
-using Test
+using Random, Test
 using TupleTools
 
 using Base: tail, front
@@ -57,3 +46,5 @@ end
 @test @inferred(TupleTools.isperm(t)) == true
 @test @inferred(TupleTools.isperm((1,2,1))) == false
 @test @inferred(TupleTools.permute(t, t)) == (p[p]...,)
+
+@test @inferred(TupleTools.diff((1, 2, 3))) == (1, 1)