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Diffstat (limited to 'examples/text-adventure/logic.rs')
| -rw-r--r-- | examples/text-adventure/logic.rs | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/examples/text-adventure/logic.rs b/examples/text-adventure/logic.rs new file mode 100644 index 0000000..5df5f6e --- /dev/null +++ b/examples/text-adventure/logic.rs @@ -0,0 +1,417 @@ +//! This module does nothing. It just creates the game's high level flow encoded as Free Monad. + + +use std::borrow::Cow; + +use higher::{run, Functor, Pure, Bind}; +use super::dsl::*; + +//Haskell has a when function, and it's nice. Sooo, copy that. +macro_rules! when { + {$a:expr => {$($b:tt)*}} => { + if($a){ + run!{$($b)*} + } else { + run!{ yield () } + } + }; +} + + +pub fn game<'a,'s : 'a>() -> FreeSausageRoll<'a, 's, ()>{ + run!{ + c <= intro(); + when!{c => { + //handle_rooms is the main game loop: Go from room to room. + c <= handle_rooms(Location::Refrigerators, Default::default()); //can't destructure in assignment in higher-0.2. Maybe later. + //if we ended up here, we left the supermarket. + ending(c.1) + }} + } +} + +fn intro<'a,'s:'a>() -> FreeSausageRoll<'a, 's, bool>{ + run!{ + present_location(Location::Entrance); + say_dialogue_line(Speaker::Partner, Cow::from("Would you be so kind as to quickly grab me a sausage roll from the supermarket? With pickle if possible?"), Mood::Friendly); + say_dialogue_line(Speaker::Partner, Cow::from("I'd meanwhile go over to the pharmacy, and buy some pills against headache."), Mood::Friendly); + c <= give_player_options(vec!["Say yes and enter the supermarket.", "Say no."]); + if c == 0 { + say_dialogue_line(Speaker::Partner, Cow::from("Thanks! We'll meet here in a couple of minutes then."), Mood::Friendly) + } + else { //as already stated: Let's just assume the interpreter validates input. + say_dialogue_line(Speaker::Partner, Cow::from("Well, I won't force you. But if I get hangry, it's going to be your problem."), Mood::Annoyed) + }; + yield c == 0 + } +} + +fn ending<'a,'s:'a>(inventory : Inventory) -> FreeSausageRoll<'a, 's, ()>{ + if inventory.items.contains(&Item::SausageRoll) { + if inventory.items.contains(&Item::Pickles){ + run!{ + say_dialogue_line(Speaker::Partner, Cow::from("Wait, seriously? You bought a glass of pickles and a sausage roll without pickle?"), Mood::Confused); + exposition("You explain that the deli counter had run out of pickles."); + say_dialogue_line(Speaker::Partner, Cow::from("Well, that's a creative solution."), Mood::Amused); + say_dialogue_line(Speaker::Partner, Cow::from("Thanks a lot, let's move on."), Mood::Happy) + } + } else { + run!{ + say_dialogue_line(Speaker::Partner, Cow::from("Thanks for the sausage roll, but there are no pickles in it?"), Mood::Annoyed); + exposition("You explain that the deli counter had run out of pickles."); + say_dialogue_line(Speaker::Partner, Cow::from("Well, that can't be helped then. Thanks a lot, let's move on."), Mood::Happy) + } + } + } else { + run!{ + say_dialogue_line(Speaker::Partner, Cow::from("What did you do in there? I asked you to bring me a sausage roll..."), Mood::Annoyed); + when!{inventory.items.len() > 0 => { + say_dialogue_line(Speaker::Partner, Cow::from("Also, why did you buy all that other stuff?"), Mood::Annoyed) + }}; + say_dialogue_line(Speaker::Partner, Cow::from("Well, let's move on, but don't complain if I get hangry on the way."), Mood::Annoyed) + } + } +} + +fn handle_rooms<'a,'s:'a>(room: Location, inventory : Inventory) -> FreeSausageRoll<'a, 's, (Location, Inventory)>{ + run!{ + c <= handle_room(room, inventory); + if c.0 != Location::Entrance { + handle_rooms(c.0, c.1) + } else { + run!{ + yield c + } + } + } +} + +fn handle_room<'a,'s:'a>(room : Location, inventory : Inventory) -> FreeSausageRoll<'a, 's, (Location, Inventory)> { + run!{ + present_location(room); + match room { + Location::Refrigerators => handle_refrigerators(inventory.clone()), + Location::Shelves => {handle_shelves(inventory.clone())}, + Location::Deli => {handle_deli(inventory.clone())}, + Location::Checkout => {handle_checkout(inventory.clone())}, + Location::Entrance => unreachable!(), //if we are at the entrance, we won. + } + } +} + +fn handle_refrigerators<'a, 's: 'a>(inventory : Inventory) -> FreeSausageRoll<'a, 's, (Location, Inventory)>{ + run!{ + c <= { + let options = if inventory.has_item_from_room(Location::Refrigerators) { + vec!["Move on to the Shelves.", "Move to the deli counter.", "Check Inventory", "Take an item", "Return an item"] + } else { + vec!["Move on to the Shelves.", "Move to the deli counter.", "Check Inventory", "Take an item"] + }; + give_player_options(options) + }; + match c { + 0 => { FreeSausageRoll::pure((Location::Shelves, inventory.clone())) }, + 1 => { FreeSausageRoll::pure((Location::Deli, inventory.clone()))}, + 2 => { + let inventory = inventory.clone(); + run!{ + check_inventory(inventory.clone()); + handle_refrigerators(inventory.clone()) + } + } + 3 => { run!{ + i <= try_take_item(inventory.clone(), Location::Refrigerators.items()); + handle_refrigerators(i) + } }, + 4 => { run!{ + i <= return_item(inventory.clone(), Location::Refrigerators); + handle_refrigerators(i) + } }, + _ => unreachable!() + } + } +} + +fn handle_shelves<'a, 's: 'a>(inventory : Inventory) -> FreeSausageRoll<'a, 's, (Location, Inventory)>{ + //this is rather similar to refrigerators. Just different items. + run!{ + c <= { + let options = if inventory.has_item_from_room(Location::Shelves) { + vec!["Move on to the Refrigerators.", "Move to the deli counter.", "Move to the checkout.", "Check Inventory","Take an item", "Return an item"] + } else { + vec!["Move on to the Shelves.", "Move to the deli counter.", "Move to the checkout.", "Check Inventory","Take an item"] + }; + give_player_options(options) + }; + match c { + 0 => { FreeSausageRoll::pure((Location::Refrigerators, inventory.clone())) }, + 1 => { FreeSausageRoll::pure((Location::Deli, inventory.clone()))}, + 2 => { FreeSausageRoll::pure((Location::Checkout, inventory.clone()))} + 3 => { + let inventory = inventory.clone(); + run!{ + check_inventory(inventory.clone()); + handle_refrigerators(inventory.clone()) + } + } + 4 => { run!{ + i <= try_take_item(inventory.clone(), Location::Shelves.items()); + handle_shelves(i) + } }, + 5 => { run!{ + i <= return_item(inventory.clone(), Location::Shelves); + handle_shelves(i) + } }, + _ => unreachable!() + } + } +} + +fn handle_deli<'a,'s:'a>(inventory : Inventory) -> FreeSausageRoll<'a, 's, (Location, Inventory)>{ + run!{ + c <= give_player_options(vec!["Move on to refrigerators.", "Move on to shelves.", "Check Inventory", "Talk to the lady behind the counter"]); + match c{ + 0 => FreeSausageRoll::pure((Location::Refrigerators, inventory.clone())), + 1 => FreeSausageRoll::pure((Location::Shelves, inventory.clone())), + 2 => { + let inventory = inventory.clone(); + run!{ + check_inventory(inventory.clone()); + handle_refrigerators(inventory.clone()) + } + }, + 3 => { + run!{ + i <= talk_to_deli_lady(inventory.clone()); + handle_deli(i.clone()) + } + }, + _ => unreachable!() + } + } +} + +fn handle_checkout<'a,'s:'a>(inventory : Inventory) -> FreeSausageRoll<'a, 's, (Location, Inventory)>{ + run!{ + c <= { + let options = if inventory.has_item_from_room(Location::Checkout) { + vec!["Move back to the shelves.", "Pay for your stuff and leave.", "Check Inventory", "Take an item", "Return an item"] + } else { + vec!["Move back to the shelves.", "Pay for your stuff and leave.", "Check Inventory", "Take an item"] + }; + give_player_options(options) + }; + match c { + 0 => { FreeSausageRoll::pure((Location::Shelves, inventory.clone())) }, + 1 => { + run!{ + r <= try_pay(inventory.clone()); + match r { + Ok(inventory) => FreeSausageRoll::pure((Location::Entrance, inventory.clone())), + Err(inventory) => handle_checkout(inventory.clone()), + } + } + }, + 2 => { + let inventory = inventory.clone(); + run!{ + check_inventory(inventory.clone()); + handle_checkout(inventory.clone()) + } + } + 3 => { run!{ + i <= try_take_item(inventory.clone(), Location::Checkout.items()); + handle_checkout(i) + } }, + 4 => { run!{ + i <= return_item(inventory.clone(), Location::Shelves); + handle_checkout(i) + } }, + _ => unreachable!() + } + } +} + +fn try_take_item<'a, 's: 'a>(inventory : Inventory, options : Vec<Item>) -> FreeSausageRoll<'a, 's,Inventory>{ + //here we run into an "interesting" issue with Rust's ownership and do-notation. + //We would like to capture inventory and use it in bind-notation, but that doesn't work (except in the first 2 lines), because Inventory isn't Copy. + //This leaves us with a couple of options: We can either pass it through by repeated cloning (done here), or leave do-notation before capturing it. + run!{ + i <= exposition("You look around and these items nearby catch your attention.").fmap(move |_| (inventory.clone(), options.clone())); + o <= give_player_options(i.1.iter().map(|o| o.description()).chain(std::iter::once("Cancel")).collect()).fmap(move |c| (c, i.0.clone(), i.1.clone())); + { + let aborted = o.2.len() <= o.0; + let updated_inventory = o.2.get(o.0).ok_or_else(|| o.1.clone()).and_then(|c| o.1.clone().try_add(*c)); + match updated_inventory { + Ok(i) => { + run! { + exposition("You take the item."); + yield (i.clone()) + } + }, + Err(i) => { + run! { + if aborted { + exposition("You changed your mind, and didn't take an item.") + } else { + exposition("You try to pick up the item, but your hands are full.") + }; + yield i.clone() + } + } + } + } + } +} + +fn return_item<'a,'s:'a>(inventory : Inventory, room : Location) -> FreeSausageRoll<'a,'s, Inventory>{ + //similar to try_take_item here the inventory can't easily be captured. For illustration purposes, here we + //don't pass it along as clones, but rather return from do-notation to capture it. + let items_in_room = room.items(); + let carried_items_from_here = inventory.items.iter().filter(|i| items_in_room.contains(i)).cloned().collect::<Vec<_>>(); + //ownership shmownership + let carried_items_from_here2 = carried_items_from_here.clone(); + let chosen = run! { + exposition("You check which items you can return here. You find places where you can return the following:"); + give_player_options(carried_items_from_here.iter().map(|o| o.description()).chain(std::iter::once("Cancel")).collect()) + }; + chosen.bind(move |c| { + match carried_items_from_here2.get(c).ok_or_else(|| inventory.clone()).and_then(|i| inventory.clone().try_remove(*i)) { + Ok(i) => { + run!{ + exposition("You put back the item."); + yield i.clone() + } + }, + Err(i) => { + run! { + exposition("You decided to not return an item."); //good enough. We filtered for valid items beforehand. + yield i.clone() + } + }, + } + }) +} + +fn check_inventory<'a, 's:'a>(inventory : Inventory) -> FreeSausageRoll<'a,'s, ()>{ + let c = inventory.items.len(); + run!{ + exposition("You look at the items you carry. You are holding:"); + list_inventory_items(inventory.clone(),0); + if c < 2 { + run!{ + exposition("You check your pocket to see how much money you have."); + exposition(Inventory::get_money()) + } + } else { + exposition("You would like to check how much money you have on you, but you need both hands to carry all the stuff you gathered.") + } + } +} + +fn list_inventory_items<'a,'s:'a>(inventory : Inventory, index : usize) -> FreeSausageRoll<'a,'s, ()>{ + if index < inventory.items.len() { + run!{ + exposition(inventory.items[index].description()); + list_inventory_items(inventory.clone(), index+1) + } + } else { + FreeSausageRoll::pure(()) + } +} + +fn talk_to_deli_lady<'a,'s:'a>(inventory : Inventory) -> FreeSausageRoll<'a,'s,Inventory>{ + run!{ + exposition("You greet the lady at the deli counter."); + say_dialogue_line(Speaker::DeliLady, Cow::from("Hi! How can I help you, dear?"), Mood::Friendly); + say_dialogue_line(Speaker::DeliLady, Cow::from("We have the most awesome fish sandwiches today. Would you like one?"), Mood::Friendly) + }.bind(move |_| deli_lady_loop(inventory.clone())) +} + +fn deli_lady_loop<'a, 's: 'a>(inventory : Inventory) -> FreeSausageRoll<'a,'s,Inventory>{ + let has_deli_item = inventory.has_item_from_room(Location::Deli); + let c = run! { + if has_deli_item { + give_player_options(vec!["Yes, please!", "No, thanks. I'd rather buy a sausage roll with pickle.", "Nothing, thanks.", "Do you take stuff from the deli back?"]) + } else { + give_player_options(vec!["Yes, please!", "No, thanks. I'd rather buy a sausage roll with pickle.", "Nothing, thanks."]) + } + }; + c.bind(move |c| { + match c { + 0 => { + let inventory = inventory.clone().try_add(Item::FishSandwich); + match inventory{ + Ok(inventory) => { + run!{ + say_dialogue_line(Speaker::DeliLady, Cow::from("Here you go! Is there anything else I can help you with? Maybe another fish sandwich?"), Mood::Happy); + deli_lady_loop(inventory.clone()) + } + }, + Err(inventory) => { + run!{ + say_dialogue_line(Speaker::DeliLady, Cow::from("I would love to hand it to you, but your hands seem kinda full. Please come back later, when you can actually carry the food I sell."), Mood::Annoyed); + yield inventory.clone() + } + }, + } + }, + 1 => { + let inventory = inventory.clone().try_add(Item::SausageRoll); + match inventory{ + Ok(inventory) => { + let d = run!{ + say_dialogue_line(Speaker::DeliLady, Cow::from("I'm sorry, but I don't have any pickles here right now. But you can take a glass from the shelf over there."), Mood::Apologetic); + say_dialogue_line(Speaker::DeliLady, Cow::from("I'll put in extra sausage to make up for it."), Mood::Apologetic); + say_dialogue_line(Speaker::DeliLady, Cow::from("Here you go! Is there anything else I can help you with? Maybe a fish sandwich?"), Mood::Happy) + }; + d.bind(move |_| deli_lady_loop(inventory.clone())) + }, + Err(inventory) => { + run!{ + say_dialogue_line(Speaker::DeliLady, Cow::from("I would love to hand it to you, but your hands seem kinda full. Please come back later, when you can actually carry the food I sell."), Mood::Annoyed); + yield inventory.clone() + } + }, + } + }, + 2 => { + let inventory = inventory.clone(); + say_dialogue_line(Speaker::DeliLady, Cow::from("So, you are just here to steal my time? I've got other customers to serve."), Mood::Annoyed) + .bind(move |_| FreeSausageRoll::pure(inventory.clone())) + }, + 3 => { + let inventory = inventory.clone(); + say_dialogue_line(Speaker::DeliLady, Cow::from("No, that would be gross. Would you buy a sandwich handed back by some other random customer?"), Mood::Confused) + .bind(move |_| FreeSausageRoll::pure(inventory.clone())) + } + _ => unreachable!() + } + }) +} + +fn try_pay<'a, 's:'a>(inventory : Inventory) -> FreeSausageRoll<'a,'s,Result<Inventory,Inventory>>{ + let total_price = inventory.total_price(); + let can_afford = inventory.can_afford(); + run!{ + exposition("You put your items onto the conveyor and wait until the cashier scans them."); + { + let line = format!("That would be €{}.{}, please.", total_price/100usize, total_price%100usize); + say_dialogue_line(Speaker::Cashier, Cow::from(line), Mood::Friendly) + }; + if can_afford { + run!{ + exposition("You hand the cashier the required amount of money."); + say_dialogue_line(Speaker::Cashier, Cow::from("Thank you very much, have a nice day!"), Mood::Friendly); + yield Ok(()) + } + } else { + run!{ + exposition("When you hear the total amount you need to pay, you blush."); + say_dialogue_line(Speaker::Cashier, Cow::from("I know that face. You haven't got enough money on you, right?"), Mood::Annoyed); + say_dialogue_line(Speaker::Cashier, Cow::from("Please bring back some items to where you took them from, and come back when you can actually pay the stuff you want to buy."), Mood::Annoyed); + yield Err(()) + } + } + }.fmap(move |e| e.map(|_| inventory.clone()).map_err(|_| inventory.clone())) +}
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