90 lines
2.9 KiB
Markdown
90 lines
2.9 KiB
Markdown
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# pacman-rules
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Welcome to pacman-rules on Exercism's Lua Track.
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If you need help running the tests or submitting your code, check out `HELP.md`.
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If you get stuck on the exercise, check out `HINTS.md`, but try and solve it without using those first :)
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## Introduction
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## Booleans
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The boolean type in Lua has the two traditional boolean values: `true` and `false`. These values can be assigned to a variable, combined with logical operators (`and`, `or`, `not`) and used in conditional tests (e.g. in control structures).
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```lua
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local is_true = true
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local is_false = false
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true and true --> true
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true and false --> false
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false or true --> true
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false or false --> false
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not false --> true
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not true --> false
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-- prints 0
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if is_true == true then
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print(0)
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else
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print(1)
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end
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```
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Conditional tests and the logical operators consider both the boolean `false` and `nil` as false and anything else as true.
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```lua
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1 and 2 --> 2
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nil and 2 --> nil
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false and 2 --> false
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1 or 2 --> 1
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false or 'hello' --> "hello"
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nil or false --> false
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```
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Both `and` and `or` uses *short-circuit evaluation*, which means they evaluate their second operand only when necessary. All operations are evaluated according to the [operator precedence](https://www.lua.org/manual/5.4/manual.html#3.4.8), where `not` is evaluated before `and` and `or`.
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## Instructions
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In this exercise, you need to implement some rules from the classic game Pac-Man.
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You have four rules to implement, all related to the game states.
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## 1. Define if Pac-Man eats a ghost
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Implement a function that takes in if Pac-Man has a power pellet active and if Pac-Man is touching a ghost and returns a boolean value if Pac-Man is able to eat the ghost. The function should return `true` only if Pac-Man has a power pellet active and is touching a ghost.
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```lua
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rules.eat_ghost(false, true)
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-- => false
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```
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## 2. Define if Pac-Man scores
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Implement a function that takes in if Pac-Man is touching a power pellet and if Pac-Man is touching a dot and returns a boolean value if Pac-Man scored. The function should return `true` if Pac-Man is touching a power pellet or a dot.
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```lua
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rules.score(true, true)
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-- => true
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```
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## 3. Define if Pac-Man loses
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Implement a function that takes in if Pac-Man has a power pellet active and if Pac-Man is touching a ghost and returns a boolean value if Pac-Man loses. The function should return `true` if Pac-Man is touching a ghost and does not have a power pellet active.
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```lua
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rules.lose(false, true)
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-- => true
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```
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## 4. Define if Pac-Man wins
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Implement a function that takes in if Pac-Man has eaten all of the dots, if Pac-Man has a power pellet active and if Pac-Man is touching a ghost and returns a boolean value if Pac-Man wins. The function should return `true` if Pac-Man has eaten all of the dots and has not lost based on the arguments defined in part 3.
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```lua
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rules.win(false, true, false)
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-- => false
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```
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## Source
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### Created by
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- @imolein
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