Merge pull request JuliaLang#49 from aawray/ex-etl

Add exercise: etl

config.json

@@ -147,6 +147,15 @@
         "filtering"
       ]
     },
+    {
+      "slug": "etl",
+      "difficulty": 2,
+      "topics": [
+        "arrays",
+        "strings",
+        "sorting"
+      ]
+    },
     {
       "slug": "bob",
       "difficulty": 2,

exercises/etl/etl.jl

@@ -0,0 +1,4 @@
+function transform(input::AbstractArray)
+
+end
+

exercises/etl/example.jl

@@ -0,0 +1,11 @@
+function transform(input::Dict)
+    output = []
+    for i = input
+        for j = map(lowercase, i[2])
+            pair = (j, i[1])
+            push!(output, pair)
+        end
+    end
+    Dict(output)
+end
+

exercises/etl/runtests.jl

@@ -0,0 +1,36 @@
+using Base.Test
+
+include("etl.jl")
+
+@testset "a single letter" begin
+    input = Dict(1=>['A'])
+    output = Dict('a'=>1)
+    @test transform(input) == output
+end
+
+@testset "single score with multiple letters" begin
+    input = Dict(1=>['A', 'E', 'I', 'O', 'U'])
+    output = Dict('a'=>1, 'e'=>1, 'i'=>1, 'o'=>1, 'u'=>1)
+    @test transform(input) == output
+end
+
+@testset "multiple scores with multiple letters" begin
+    input = Dict(1=>['A', 'E'], 2=>['D', 'G'])
+    output = Dict('g'=>2, 'e'=>1, 'a'=>1, 'd'=>2)
+    @test transform(input) == output
+end
+
+@testset "multiple scores with differing numbers of letters" begin
+    input = Dict(1=>[ 'A', 'E', 'I', 'O', 'U', 'L', 'N', 'R', 'S', 'T' ],
+                 2=>[ 'D', 'G' ], 3=>[ 'B', 'C', 'M', 'P' ],
+                 4=>[ 'F', 'H', 'V', 'W', 'Y' ], 5=>[ 'K' ],
+                 8=>[ 'J', 'X' ], 10=>[ 'Q', 'Z' ])
+    output = Dict('a'=>1, 'b'=>3,  'c'=>3, 'd'=>2, 'e'=>1,
+                  'f'=>4, 'g'=>2,  'h'=>4, 'i'=>1, 'j'=>8,
+                  'k'=>5, 'l'=>1,  'm'=>3, 'n'=>1, 'o'=>1,
+                  'p'=>3, 'q'=>10, 'r'=>1, 's'=>1, 't'=>1,
+                  'u'=>1, 'v'=>4,  'w'=>4, 'x'=>8, 'y'=>4,
+                  'z'=>10)
+    @test transform(input) == output
+end
+