backport findprev, findlast & tests

See e3aa57e

Author: StefanKarpinski

Diff for: src/Compat.jl

@@ -310,4 +310,29 @@ else
     import Base: Libc, Libdl
 end
 
+if VERSION < v"0.4.0-dev+2418"
+    function findprev(A, start)
+        for i = start:-1:1
+            A[i] != 0 && return i
+        end
+        0
+    end
+    findlast(A) = findprev(A, length(A))
+    function findprev(A, v, start)
+        for i = start:-1:1
+            A[i] == v && return i
+        end
+        0
+    end
+    findlast(A, v) = findprev(A, v, length(A))
+    function findprev(testf::Function, A, start)
+        for i = start:-1:1
+            testf(A[i]) && return i
+        end
+        0
+    end
+    findlast(testf::Function, A) = findprev(testf, A, length(A))
+    export findprev, findlast
+end
+
 end # module

Diff for: test/runtests.jl

@@ -238,3 +238,20 @@ let A, B, s
     end
     @test s == 210
 end
+
+# findlast, findprev
+let a = [0,1,2,3,0,1,2,3]
+    @test findlast(a) == 8
+    @test findlast(a.==0) == 5
+    @test findlast(a.==5) == 0
+    @test findlast([1,2,4,1,2,3,4], 3) == 6
+    @test findlast(isodd, [2,4,6,3,9,2,0]) == 5
+    @test findlast(isodd, [2,4,6,2,0]) == 0
+    @test findprev(a,4) == 4
+    @test findprev(a,5) == 4
+    @test findprev(a,1) == 0
+    @test findprev(a,1,4) == 2
+    @test findprev(a,1,8) == 6
+    @test findprev(isodd, [2,4,5,3,9,2,0], 7) == 5
+    @test findprev(isodd, [2,4,5,3,9,2,0], 2) == 0
+end