Add wedding-woes exercise (#438)

* wedding-woes: add exercise

* wedding-woes: add exercise

config.json

@@ -42,6 +42,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "wedding-woes",
+        "name": "wedding-woes",
+        "uuid": "e11fad7c-c21f-49af-a607-9df50ef5fa41",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
+      },
       {
         "slug": "queen-attack",
         "name": "Queen Attack",

exercises/practice/wedding-woes/.docs/hints.md

@@ -0,0 +1,33 @@
+# Hints
+
+## General
+
+- The [Prolog basics page](https://www.tutorialspoint.com/prolog/prolog_basics.htm) explains what facts and rules are and how to define them
+
+## 1. List the chatty people
+
+- You're defining a [fact](https://www.tutorialspoint.com/prolog/prolog_basics.htm)
+- You can define multiple "instances" of the same fact
+- Remember to use lowercase names
+
+## 2. List who likes whom
+
+- You're defining a [fact](https://www.tutorialspoint.com/prolog/prolog_basics.htm)
+- You can define multiple "instances" of the same fact
+- Remember to use lowercase names
+- The first argument is the person liking the other person
+- The second argument is the person being liked by the other person
+
+## 3. People who like each other make a good pairing
+
+- You're defining a [rule](https://www.tutorialspoint.com/prolog/prolog_basics.htm)
+- In Prolog, making sure that two facts/rules are both true is done via a [conjunction](https://www.tutorialspoint.com/prolog/prolog_conjunctions_and_disjunctions.htm)
+
+## 4. Chatty people pair with anyone
+
+- You're defining a [rule](https://www.tutorialspoint.com/prolog/prolog_basics.htm)
+- In Prolog, making sure that at least one of two facts/rules is true is done via a [disjunction](https://www.tutorialspoint.com/prolog/prolog_conjunctions_and_disjunctions.htm)
+
+## 5. Check seating arrangement
+
+- You're defining a [rule](https://www.tutorialspoint.com/prolog/prolog_basics.htm)

exercises/practice/wedding-woes/.docs/instructions.md

@@ -0,0 +1,68 @@
+# Instructions
+
+Your task is to find the perfect table seating.
+You'll do this by declaring _facts_ (things that are always true) and _rules_ (things that are conditionally true).
+
+## 1. List the chatty people
+
+Define the `chatty` fact to represent the chatty people.
+The `chatty` fact takes a single argument: the chatty person's lowercase name.
+
+```prolog
+chatty(gustavo).
+true.
+```
+
+## 2. List who likes whom
+
+Define the `likes` fact to represent who likes whom.
+The `likes` fact takes two arguments:
+
+1. The lowercase name of the person liking the other person
+2. The lowercase name of the person being liked
+
+```prolog
+likes(esteban, malena).
+true.
+```
+
+## 3. People who like each other make a good pairing
+
+Define the `pairing` rule to be true when the two people both like each other.
+The pairing rule takes two arguments:
+
+1. The lowercase name of the first person
+2. The lowercase name of the second person
+
+```prolog
+pairing(malena, esteban).
+true.
+```
+
+## 4. Chatty people pair with anyone
+
+Define the `pairing` rule to be true when (at least) one of the two people being paired is chatty.
+
+```prolog
+pairing(valeria, jaime).
+true.
+```
+
+## 5. Check seating arrangement
+
+Define the `seating` rule to be true when all five pairs are good pairings.
+
+The pairing rule takes fives arguments:
+
+1. The lowercase name of the first person
+2. The lowercase name of the second person
+3. The lowercase name of the third person
+4. The lowercase name of the fourth person
+5. The lowercase name of the fifth person
+
+Use the just defined facts and rules to check the seating arrangement.
+
+```prolog
+seating(esteban, jaime, gustavo, malena, valeria).
+false.
+```

exercises/practice/wedding-woes/.docs/introduction.md

@@ -0,0 +1,24 @@
+# Introduction
+
+Your best friend is getting married and asked you to be their wedding planner.
+You agreed, though everything you know about it is from a movie...
+Things were going smoothly, until you started working on the table seating.
+
+Five guests will be attending, seated around one big, round table.
+Here's the guest list:
+
+- Esteban, Gustavo, Jaime, Malena, and Valeria.
+
+Your goal is to find a seating arrangement where everyone is happy with their neighbors.
+You don't know everyone quite as well as you'd like, but here's what you do know:
+
+- Gustavo is chatty
+- Valeria is chatty
+- Esteban likes Malena
+- Malena likes Esteban
+- Rico likes Naran (but not vice versa!)
+
+People who like each other can be seated next to each other, but only when they both feel that way.
+Chatty people intermingle easily and can be seated next to anyone.
+
+With these details in hand, it's time to sketch out a seating arrangement!

exercises/practice/wedding-woes/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "erikschierboom"
+  ],
+  "files": {
+    "solution": [
+      "wedding_woes.pl"
+    ],
+    "test": [
+      "wedding_woes_tests.plt"
+    ],
+    "example": [
+      ".meta/wedding_woes.example.pl"
+    ]
+  },
+  "blurb": "Infer family relations from some basic facts."
+}

exercises/practice/wedding-woes/.meta/wedding_woes.example.pl

@@ -0,0 +1,10 @@
+chatty(gustavo).
+chatty(valeria).
+
+likes(esteban, malena).
+likes(malena, esteban).
+likes(gustavo, valeria).
+
+pairing(First, Second) :- likes(First, Second), likes(Second, First).
+pairing(First, Second) :- chatty(First); chatty(Second).
+seating(A, B, C, D, E) :- pairing(A, B), pairing(B, C), pairing(C, D), pairing(D, E), pairing(E, A).

exercises/practice/wedding-woes/wedding_woes.pl

@@ -0,0 +1,7 @@
+% Define the 'chatty' fact
+
+% Define the 'lines' fact
+
+% Define the 'pairing' rule
+
+% Define the 'seating' rule

exercises/practice/wedding-woes/wedding_woes_tests.plt

@@ -0,0 +1,48 @@
+pending :-
+    current_prolog_flag(argv, ['--all'|_]).
+pending :-
+    write('\nA TEST IS PENDING!\n'),
+    fail.
+
+:- begin_tests(wedding_woes).
+
+    test(gustavo_is_chatty, condition(true)) :-
+        chatty(gustavo).
+
+    test(valeria_is_chatty, condition(pending)) :-
+        chatty(valeria).
+
+    test(jaime_is_not_chatty, [fail, condition(pending)]) :-
+        chatty(jaime).
+
+    test(esteban_likes_malena, condition(pending)) :-
+        likes(esteban, malena).
+
+    test(malena_likes_esteban, condition(pending)) :-
+        likes(malena, esteban).
+
+    test(gustavo_likes_valeria, condition(pending)) :-
+        likes(gustavo, valeria).
+
+    test(valeria_does_not_like_gustavo, [fail, condition(pending)]) :-
+        likes(valeria, gustavo).
+
+    test(people_who_like_each_other_make_a_good_pairing, condition(pending)) :-
+        pairing(malena, esteban).
+
+    test(two_chatty_people_make_a_good_pairing, condition(pending)) :-
+        pairing(gustavo, jaime).
+
+    test(one_chatty_person_make_a_good_pairing_with_anyone, condition(pending)) :-
+        pairing(valeria, jaime).
+
+    test(people_who_dont_like_each_other_and_are_not_chatty_dont_make_a_good_pairing, [fail, condition(pending)]) :-
+        pairing(rico, naran).
+
+    test(valid_seating, condition(pending)) :-
+        seating(esteban, malena, gustavo, jaime, valeria).
+
+    test(invalid_seating, [fail, condition(pending)]) :-
+        seating(esteban, jaime, gustavo, malena, valeria).
+
+:- end_tests(wedding_woes).