Add two-fer (#218)

config.json

@@ -226,6 +226,14 @@
           "math"
         ]
       },
+      {
+        "slug": "two-fer",
+        "name": "Two-Fer",
+        "uuid": "b186e735-f638-4836-97c1-9c78c5e0078e",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "raindrops",
         "name": "Raindrops",

exercises/practice/two-fer/.docs/instructions.md

@@ -0,0 +1,24 @@
+# Instructions
+
+Your task is to determine what you will say as you give away the extra cookie.
+
+If you know the person's name (e.g. if they're named Do-yun), then you will say:
+
+```text
+One for Do-yun, one for me.
+```
+
+If you don't know the person's name, you will say _you_ instead.
+
+```text
+One for you, one for me.
+```
+
+Here are some examples:
+
+| Name   | Dialogue                    |
+| :----- | :-------------------------- |
+| Alice  | One for Alice, one for me.  |
+| Bohdan | One for Bohdan, one for me. |
+|        | One for you, one for me.    |
+| Zaphod | One for Zaphod, one for me. |

exercises/practice/two-fer/.docs/introduction.md

@@ -0,0 +1,8 @@
+# Introduction
+
+In some English accents, when you say "two for" quickly, it sounds like "two fer".
+Two-for-one is a way of saying that if you buy one, you also get one for free.
+So the phrase "two-fer" often implies a two-for-one offer.
+
+Imagine a bakery that has a holiday offer where you can buy two cookies for the price of one ("two-fer one!").
+You take the offer and (very generously) decide to give the extra cookie to someone else in the queue.

exercises/practice/two-fer/.gitignore

@@ -0,0 +1,11 @@
+## -*- conf -*-
+.rebar3
+_build/
+ebin/
+erl_crash.dump
+rebar3.crashdump
+
+tmp
+bin/configlet
+bin/configlet.exe
+CHECKLIST

exercises/practice/two-fer/.meta/config.json

@@ -0,0 +1,18 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "src/two-fer.lfe"
+    ],
+    "test": [
+      "test/two-fer-tests.lfe"
+    ],
+    "example": [
+      ".meta/example.lfe"
+    ]
+  },
+  "blurb": "Create a sentence of the form \"One for X, one for me.\".",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/757"
+}

exercises/practice/two-fer/.meta/example.lfe

@@ -0,0 +1,6 @@
+(defmodule two-fer
+  (export (two-fer 1)))
+
+(defun two-fer
+    (("") "One for you, one for me.")
+    ((name) (++ "One for " name ", one for me.")))

exercises/practice/two-fer/.meta/tests.toml

@@ -0,0 +1,19 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[1cf3e15a-a3d7-4a87-aeb3-ba1b43bc8dce]
+description = "no name given"
+
+[b4c6dbb8-b4fb-42c2-bafd-10785abe7709]
+description = "a name given"
+
+[3549048d-1a6e-4653-9a79-b0bda163e8d5]
+description = "another name given"

exercises/practice/two-fer/Makefile

@@ -0,0 +1,21 @@
+ERL    := $(shell which erl)
+REBAR3 := $(shell which rebar3)
+
+null  :=
+space := $(null) #
+comma := ,
+
+ifeq ($(ERL),)
+  $(error Can't find Erlang executable 'erl')
+else ifeq ($(REBAR3),)
+  $(error Can't find rebar3)
+endif
+
+compile: ; $(REBAR3) compile
+
+clean: ; $(REBAR3) clean
+
+.PHONY: test
+test:
+	$(REBAR3) eunit \
+	-m $(subst $(space),$(comma),$(basename $(notdir $(wildcard test/*.lfe))))

exercises/practice/two-fer/rebar.config

@@ -0,0 +1,11 @@
+{plugins, [{rebar3_lfe, "0.4.3"}]}.
+
+{provider_hooks, [{post, [{compile, {lfe, compile}}]}]}.
+
+{deps, [{lfe, "2.1.1"}]}.
+
+{profiles,
+ [{test,
+   [{eunit_compile_opts, [{src_dirs, ["src", "test"]}]},
+    {deps,
+     [{ltest, "0.13.3"}]}]}]}.

exercises/practice/two-fer/rebar.lock

@@ -0,0 +1,8 @@
+{"1.2.0",
+[{<<"lfe">>,{pkg,<<"lfe">>,<<"2.1.1">>},0}]}.
+[
+{pkg_hash,[
+ {<<"lfe">>, <<"4A888B26172D198DC7A5AFEB897E8248AF7D56E1638D9C8249AAF933AE811B96">>}]},
+{pkg_hash_ext,[
+ {<<"lfe">>, <<"C484D3B655D40DED58BC41B17B22F173711C681BF36063A234A9BAA9506947E1">>}]}
+].

exercises/practice/two-fer/src/two-fer.app.src

@@ -0,0 +1,11 @@
+%% -*- erlang -*-
+{application, 'two-fer',
+ [{description, ""},
+  {vsn, "0.0.1"},
+  {modules,
+   ['two-fer']},
+  {registered, []},
+  {applications,
+   [kernel, stdlib]},
+  {included_applications, []},
+  {env, []}]}.

exercises/practice/two-fer/src/two-fer.lfe

@@ -0,0 +1,4 @@
+(defmodule two-fer
+  (export (two-fer 1)))
+
+    ; please define the two-fer function.

exercises/practice/two-fer/test/two-fer-tests.lfe

@@ -0,0 +1,14 @@
+(defmodule two-fer-tests
+  (behaviour ltest-unit)
+  (export all))
+
+(include-lib "ltest/include/ltest-macros.lfe")
+
+(deftest no-name-given
+  (is-equal "One for you, one for me." (two-fer:two-fer "")))
+
+(deftest a-name-given
+  (is-equal "One for Alice, one for me." (two-fer:two-fer "Alice")))
+
+(deftest another-name-given
+  (is-equal "One for Bob, one for me." (two-fer:two-fer "Bob")))