add pangram exercise (#190)

config.json

@@ -359,6 +359,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 1
+      },
+      {
+        "slug": "pangram",
+        "name": "Pangram",
+        "uuid": "d319360a-afef-4b65-be5f-da45d48367cb",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
       }
     ]
   },

exercises/practice/pangram/.docs/instructions.md

@@ -0,0 +1,8 @@
+# Instructions
+
+Your task is to figure out if a sentence is a pangram.
+
+A pangram is a sentence using every letter of the alphabet at least once.
+It is case insensitive, so it doesn't matter if a letter is lower-case (e.g. `k`) or upper-case (e.g. `K`).
+
+For this exercise, a sentence is a pangram if it contains each of the 26 letters in the English alphabet.

exercises/practice/pangram/.docs/introduction.md

@@ -0,0 +1,16 @@
+# Introduction
+
+You work for a company that sells fonts through their website.
+They'd like to show a different sentence each time someone views a font on their website.
+To give a comprehensive sense of the font, the random sentences should use **all** the letters in the English alphabet.
+
+They're running a competition to get suggestions for sentences that they can use.
+You're in charge of checking the submissions to see if they are valid.
+
+~~~~exercism/note
+Pangram comes from Greek, παν γράμμα, pan gramma, which means "every letter".
+
+The best known English pangram is:
+
+> The quick brown fox jumps over the lazy dog.
+~~~~

exercises/practice/pangram/.gitignore

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

exercises/practice/pangram/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "src/pangram.lfe"
+    ],
+    "test": [
+      "test/pangram-tests.lfe"
+    ],
+    "example": [
+      ".meta/example.lfe"
+    ]
+  },
+  "blurb": "Determine if a sentence is a pangram.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Pangram"
+}

exercises/practice/pangram/.meta/example.lfe

@@ -0,0 +1,6 @@
+(defmodule pangram
+  (export (pangram? 1)))
+
+(defun pangram? (sentence)
+  (ordsets:is_subset (lists:seq #\a #\z)
+                     (ordsets:from_list (string:lowercase sentence))))

exercises/practice/pangram/.meta/tests.toml

@@ -0,0 +1,45 @@
+# 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.
+
+[64f61791-508e-4f5c-83ab-05de042b0149]
+description = "empty sentence"
+
+[74858f80-4a4d-478b-8a5e-c6477e4e4e84]
+description = "perfect lower case"
+
+[61288860-35ca-4abe-ba08-f5df76ecbdcd]
+description = "only lower case"
+
+[6564267d-8ac5-4d29-baf2-e7d2e304a743]
+description = "missing the letter 'x'"
+
+[c79af1be-d715-4cdb-a5f2-b2fa3e7e0de0]
+description = "missing the letter 'h'"
+
+[d835ec38-bc8f-48e4-9e36-eb232427b1df]
+description = "with underscores"
+
+[8cc1e080-a178-4494-b4b3-06982c9be2a8]
+description = "with numbers"
+
+[bed96b1c-ff95-45b8-9731-fdbdcb6ede9a]
+description = "missing letters replaced by numbers"
+
+[938bd5d8-ade5-40e2-a2d9-55a338a01030]
+description = "mixed case and punctuation"
+
+[2577bf54-83c8-402d-a64b-a2c0f7bb213a]
+description = "case insensitive"
+include = false
+
+[7138e389-83e4-4c6e-8413-1e40a0076951]
+description = "a-m and A-M are 26 different characters but not a pangram"
+reimplements = "2577bf54-83c8-402d-a64b-a2c0f7bb213a"

exercises/practice/pangram/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/pangram/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/pangram/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/pangram/src/pangram.app.src

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

exercises/practice/pangram/src/pangram.lfe

@@ -0,0 +1,4 @@
+(defmodule pangram
+  (export (pangram? 1)))
+
+  ; Please implement the pangram? function.

exercises/practice/pangram/test/pangram-tests.lfe

@@ -0,0 +1,35 @@
+(defmodule pangram-tests
+  (behaviour ltest-unit)
+  (export all))
+
+(include-lib "ltest/include/ltest-macros.lfe")
+
+(deftest empty-sentence
+  (is-not (pangram:pangram? "")))
+
+(deftest perfect-lower-case
+  (is (pangram:pangram? "abcdefghijklmnopqrstuvwxyz")))
+
+(deftest only-lower-case
+  (is (pangram:pangram? "the quick brown fox jumps over the lazy dog")))
+
+(deftest missing-the-letter-x
+  (is-not (pangram:pangram? "a quick movement of the enemy will jeopardize five gunboats")))
+
+(deftest missing-the-letter-h
+  (is-not (pangram:pangram? "five boxing wizards jump quickly at it")))
+
+(deftest with-underscores
+  (is (pangram:pangram? "the_quick_brown_fox_jumps_over_the_lazy_dog")))
+
+(deftest with-numbers
+  (is (pangram:pangram? "the 1 quick brown fox jumps over the 2 lazy dogs")))
+
+(deftest missing-letters-replaced-by-numbers
+  (is-not (pangram:pangram? "7h3 qu1ck brown fox jumps ov3r 7h3 lazy dog")))
+
+(deftest mixed-case-and-punctuation
+  (is (pangram:pangram? "\"Five quacking Zephyrs jolt my wax bed.\"")))
+
+(deftest a-to-m-and-A-to-M-are-twenty-six-different-characters-but-not-a-pangram
+  (is-not (pangram:pangram? "abcdefghijklm ABCDEFGHIJKLM")))