[Annalyns Infiltration] concept exercise (#782)

config.json

@@ -45,6 +45,18 @@
         ],
         "prerequisites": [],
         "status": "wip"
+      },
+      {
+        "slug": "annalyns-infiltration",
+        "name": "Annalyns Infiltration",
+        "uuid": "603c7f88-5250-427e-b5d8-f8306fdd9b03",
+        "concepts": [
+          "booleans"
+        ],
+        "prerequisites": [
+          "basics"
+        ],
+        "status": "wip"
       }
     ],
     "practice": [

exercises/concept/annalyns-infiltration/.docs/hints.md

@@ -0,0 +1,23 @@
+# Hints
+
+## General
+
+- There are three [boolean operators][boolean-operators] to work with boolean values.
+- Multiple operators can be combined in a single expression.
+
+## 1. Check if a fast attack can be made
+
+- The logical NOT operator (`!`) can be placed before an expression to negate its value.
+
+## 2. Check if the group can be spied upon
+
+- Boolean operators are typically used to evaluate whether two or more expressions are true or not true.
+
+## 3. Check if the prisoner can be signaled
+
+- Boolean operators execute in the order of their precedence (from highest to lowest): `!`, `&&`, `||`.
+- In general, use of parentheses is encouraged to make your intention clearer.
+- For more details check out the Operator Precedence section on the [official Julia documentation][operator-precedence].
+
+[boolean-operators]: https://docs.julialang.org/en/v1/manual/mathematical-operations/#Boolean-Operators
+[operator-precedence]: https://docs.julialang.org/en/v1/manual/mathematical-operations/#Operator-Precedence-and-Associativity

exercises/concept/annalyns-infiltration/.docs/instructions.md

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+# Instructions
+
+In this exercise, you'll be writing some logic for a video game a friend is developing.
+The game's main character is Annalyn, a brave girl with a fierce and loyal pet dog.
+Unfortunately, disaster strikes, as her best friend is kidnapped while searching for berries in the forest.
+Annalyn will try to find and free her friend, optionally taking her dog with her on this quest.
+
+Annalyn eventually finds the camp in which her friend is imprisoned and it turns out there are two kidnappers: a mighty knight and a cunning archer.
+
+The player is presented with some options for what to do next.
+For each of the four possible options you need to write a function that tells the game whether it should show that option or not.
+
+## 1. Check if the 'Fast Attack' option should be shown
+
+If the knight is sleeping, then Annalyn will be able to make a quick attack into the camp before he can wake up properly and get his armour on.
+
+Implement a function named `can_do_fast_attack` that takes a boolean value which indicates if the knight is awake.
+This function returns `true` if the 'Fast Attack' action is available based on the state of the character. Otherwise, returns `false`:
+
+```julia-repl
+julia> knight_awake = true
+
+julia> can_do_fast_attack(knight_awake)
+false
+```
+
+## 2. Check if the 'Spy' option should be shown
+
+The group can be spied upon if at least one of them is awake. Otherwise, spying is a waste of time.
+
+Implement a function named `can_spy` that takes three boolean values, indicating if the knight, archer and prisoner, respectively, are awake.
+The function returns `true` if the 'Spy' action is available based on the state of the characters.
+Otherwise, returns `false`:
+
+```julia-repl
+# Output suppressed from the next 3 lines
+julia> knight_awake = false
+julia> archer_awake = true
+julia> prisoner_awake = false
+
+julia> can_spy(knight_awake, archer_awake, prisoner_awake)
+true
+```
+
+## 3. Check if the 'Signal Prisoner' option should be shown
+
+The prisoner can be signalled using bird sounds if she is awake and the archer is sleeping.
+If the archer is awake then  can't be safely signaled because the archer is also trained in bird signalling.
+
+Implement a function named `can_signal_prisoner` that takes two boolean values, indicating if the archer and prisoner, respectively, are awake.
+The function returns `true` if the 'Signal Prisoner' action is available based on the state of the characters.
+Otherwise, returns `false`:
+
+```julia-repl
+julia> archer_awake = false
+julia> prisoner_awake = true
+
+julia> can_signal_prisoner(archer_awake, prisoner_awake)
+true
+```
+
+## 4. Check if the 'Free Prisoner' option should be shown
+
+Annalyn can try sneaking into the camp to free her friend. This is a risky thing to do and can only succeed in one of two ways:
+
+- If Annalyn has her pet dog with her she can rescue the prisoner if the archer is asleep.
+  The knight is scared of the dog and the archer will not have time to get ready before Annalyn and her friend can escape.
+
+- If Annalyn does not have her dog then she and the prisoner must be very sneaky!
+  Annalyn can free the prisoner if they are awake and the knight and archer are both sleeping, but if he prisoner is sleeping they can't be rescued: they would be startled by Annalyn's sudden appearance and wake up the knight and archer.
+
+Implement a function named `can_free_prisoner` that takes four boolean values.
+The first three parameters indicate if the knight, archer and prisoner, respectively, are awake.
+The last parameter indicates if Annalyn's pet dog is present.
+The function returns `true` if the 'Free Prisoner' action is available based on the state of the characters. Otherwise, it returns `false`:
+
+```julia-repl
+julia> knight_awake = false
+julia> archer_awake = true
+julia> prisoner_awake = false
+julia> dog_present = false
+
+julia> can_free_prisoner(knight_awake, archer_awake, prisoner_awake, dog_present)
+false
+```

exercises/concept/annalyns-infiltration/.docs/introduction.md

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+# Introduction
+
+## Booleans in Julia
+
+True or false values are represented by the `Bool` type.
+It contains only two values: `true` and `false`.
+
+```julia-repl
+julia> true
+true
+
+julia> false
+false
+```
+
+## Boolean Operators
+
+There are three Boolean operators in Julia.
+
+`&&` is Boolean "and".
+It evaluates to `true` if the expressions on *both* sides of `&&` are `true`.
+
+```julia-repl
+julia> true && true
+true
+
+julia> true && false
+false
+```
+
+`||` is Boolean "or".
+It evaluates to `true` if an expression on *either* side of `||` is `true`.
+
+```julia-repl
+julia> true || true
+true
+
+julia> false || true
+true
+```
+
+`!` is Boolean "not".
+It exchanges `true` and `false` values.
+
+```julia-repl
+julia> !true
+false
+
+julia> !false
+true
+```
+
+For longer and more complicated expressions, it is best to use parentheses to make your intention clear.
+
+```julia-repl
+julia> (true || false) && (false && true)
+false
+```

exercises/concept/annalyns-infiltration/.docs/source.md

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+# Source
+
+This exercise is based on the ["Booleans" exercise][source] of the Javascript track, designed by [Rishi Kothari][rishiosaur] and [Derk-Jan Karrenbeld][sleepless].
+
+[source]: https://github.com/exercism/v3/tree/1b7c392e1cc576f3948ed55216611c42fabb19b1/languages/javascript/exercises/concept/booleans
+[rishiosaur]: https://github.com/rishiosaur
+[sleepless]: https://github.com/SleeplessByte

exercises/concept/annalyns-infiltration/.meta/config.json

@@ -0,0 +1,26 @@
+{
+  "authors": [
+    "SaschaMann",
+    "colinleach"
+  ],
+  "contributors": [
+    "cmcaine",
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "annalyns-infiltration.jl"
+    ],
+    "test": [
+      "runtests.jl"
+    ],
+    "exemplar": [
+      ".meta/exemplar.jl"
+    ]
+  },
+  "language_versions": "≥1.0",
+  "forked_from": [
+    "javascript/annalyns-infiltration"
+  ],
+  "blurb": "Learn about boolean expressions by implementing the quest logic for a new RPG."
+}

exercises/concept/annalyns-infiltration/.meta/exemplar.jl

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+"""
+    can_do_fast_attack(knight_awake)
+
+Return if a fast attack is possible.
+"""
+can_do_fast_attack(knight_awake) = !knight_awake
+
+"""
+    can_spy(knight_awake, archer_awake, prisoner_awake)
+
+Return if the spy action is possible.
+"""
+can_spy(knight_awake, archer_awake, prisoner_awake) = knight_awake || archer_awake || prisoner_awake
+
+"""
+    can_signal_prisoner(archer_awake, prisoner_awake)
+
+Return if signaling the prisoner is possible.
+"""
+can_signal_prisoner(archer_awake, prisoner_awake) = prisoner_awake && !archer_awake
+
+"""
+    can_free_prisoner(knight_awake, archer_awake, prisoner_awake, dog_present)
+
+Return if the prisoner can be freed.
+"""
+can_free_prisoner(knight_awake, archer_awake, prisoner_awake, dog_present) = 
+                    !knight_awake && !archer_awake && prisoner_awake || dog_present && !archer_awake

exercises/concept/annalyns-infiltration/annalyns-infiltration.jl

@@ -0,0 +1,11 @@
+function can_do_fast_attack(knight_awake)
+end
+
+function can_spy(knight_awake, archer_awake, prisoner_awake)
+end
+
+function can_signal_prisoner(archer_awake, prisoner_awake)
+end
+
+function can_free_prisoner(knight_awake, archer_awake, prisoner_awake, dog_present)
+end

exercises/concept/annalyns-infiltration/runtests.jl

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+using Test
+
+include("annalyns-infiltration.jl")
+
+# Julia 1.0 compat
+# The function definition of eachrow is taken from Julia Base,
+# released under the MIT license: https://julialang.org/license
+if VERSION < v"1.1"
+    @eval eachrow(A) = (view(A, i, :) for i in axes(A, 1))
+end
+
+@testset verbose = true "tests" begin
+    @testset "fast attack" begin
+        @test !can_do_fast_attack(true)
+        @test  can_do_fast_attack(false)
+    end
+
+    @testset "spying" begin
+        character_state_combinations = Bool[
+            0 0 0 0;
+            0 0 1 1;
+            0 1 0 1;
+            0 1 1 1;
+            1 0 0 1;
+            1 0 1 1;
+            1 1 1 1;
+        ]
+
+        for state in eachrow(character_state_combinations)
+            @test can_spy(state[1:3]...) == state[4]
+        end
+    end
+
+    @testset "signaling prisoner" begin
+        character_state_combinations = Bool[
+            0 0 0;
+            0 1 1;
+            1 0 0;
+            1 1 0;
+        ]
+
+        for state in eachrow(character_state_combinations)
+            @test can_signal_prisoner(state[1:2]...) == state[3]
+        end
+    end
+
+    @testset "freeing prisoner" begin
+        character_state_combinations = Bool[
+            0 0 0 0 0;
+            0 0 0 1 1;
+            0 0 1 0 1;
+            0 0 1 1 1;
+            0 1 0 0 0;
+            0 1 0 1 0;
+            0 1 1 0 0;
+            0 1 1 1 0;
+            1 0 0 0 0;
+            1 0 0 1 1;
+            1 0 1 0 0;
+            1 0 1 1 1;
+            1 1 0 0 0;
+            1 1 0 1 0;
+            1 1 1 0 0;
+            1 1 1 1 0;
+        ]
+
+        for state in eachrow(character_state_combinations)
+            @test can_free_prisoner(state[1:4]...) == state[5]
+        end
+    end
+end