Initial Commit

lua/accumulate/README.md

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+# Accumulate
+
+Implement the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection.
+
+For example, given the collection of numbers:
+
+- 1, 2, 3, 4, 5
+
+And the operation:
+
+- square a number
+
+Your code should be able to produce the collection of squares:
+
+- 1, 4, 9, 16, 25
+
+Check out the test suite to see the expected function signature.
+
+## Restrictions
+
+Keep your hands off that collect/map/fmap/whatchamacallit functionality
+provided by your standard library!
+Solve this one yourself using other basic tools instead.
+
+Elixir specific: it's perfectly fine to use `Enum.reduce` or
+`Enumerable.reduce`.
+
+Lisp specific: it's perfectly fine to use `MAPCAR` or the equivalent,
+as this is idiomatic Lisp, not a library function.
+
+### Getting started
+First install lua and [luarocks][2] using [homebrew][1]
+
+    $ brew install lua
+
+Then install [busted][3] testing framework for lua
+
+    $ luarocks install busted
+
+Then run your test
+
+    $ busted bob_test.lua
+
+Other resources
+
+  1. [Lua Style Guide][4]
+  2. [Learn Lua in 15 minutes][5]
+
+[1]: http://brew.sh/
+[2]: http://luarocks.org/
+[3]: http://olivinelabs.com/busted/
+[4]: https://github.com/Olivine-Labs/lua-style-guide
+[5]: http://tylerneylon.com/a/learn-lua/
+
+## Source
+
+Conversation with James Edward Gray II [view source](https://twitter.com/jeg2)

lua/accumulate/accumulate_spec.lua

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+local accumulate = require('accumulate')
+
+describe('accumulate', function()
+
+  local function square(x) return x * x end
+
+  it('should accumulate over an empty array', function()
+    assert.are.same({}, accumulate({}, square))
+  end)
+
+  it('should accumulate over an array with a single element', function()
+    assert.are.same({ 4 }, accumulate({ 2 }, square))
+  end)
+
+  it('should accumulate over an array with several elements', function()
+    assert.are.same({ 1, 4, 9 }, accumulate({ 1, 2, 3 }, square))
+  end)
+
+  it('should accumulate over an array with a different function', function()
+    assert.are.same({ 'HELLO', 'WORLD' }, accumulate({ 'hello', 'world' }, string.upper))
+  end)
+
+end)