├── Readme.md
├── all-levels.txt
├── call-by-push-block-no-buffering.hs
├── call-by-push-block-ungolfed.hs
├── call-by-push-block.hs
├── encode-levels
├── Encode.hs
├── ghc-unicode-chars.txt
└── levels-raw.txt
└── puzzle-scratch.txt
/Readme.md:
--------------------------------------------------------------------------------
1 | # Call-by-push-block
2 |
3 | Call-by-push-block is a sokoban game written in 10 lines of Haskell for the Feb
4 | '23 [Haskell Tiny Game Jam](https://github.com/haskell-game/tiny-games-hs). It
5 | is for the Prelude category and so does not use any imports.
6 |
7 | In Call-by-push-block, you are code golfing. To clear a level, you must move the
8 | lambda (`λ`) to push a block (`o`) into every hole (`_`).
9 |
10 | Your score is the number of moves you take. Like in real golf, a lower
11 | score is better, but make sure you can complete the level first before you
12 | try to get the best score.
13 |
14 | There are 15 levels of roughly increasing difficulty. They will take around an
15 | hour to complete, depending on experience. Your scores for each level are given
16 | at the end: compete with your friends to see who can get the lowest scores!
17 |
18 | ## General advice
19 |
20 | - You need to press Enter to submit your move (a quirk of this entry being in
21 | the Prelude category).
22 | - Try everything! You can always undo or reset if you reach an unsolvable
23 | state.
24 | - Read the [Controls in detail](#controls-in-detail) section if you're confused by the controls.
25 | - Read the "Hints" section if you get stuck.
26 |
27 | ## Quick start
28 |
29 | ### I have Haskell installed
30 |
31 | Run this for the vanilla user experience (`stack runghc` works too).
32 |
33 | ``` bash
34 | $ runghc call-by-push-block.hs
35 | ```
36 |
37 | Run this version if you do not like having to press Enter after every move. Note
38 | that this version is provided for convenience and does not fit the rules and
39 | category of the game jam.
40 |
41 | ``` bash
42 | $ runghc call-by-push-block-no-buffering.hs
43 | ```
44 |
45 | ### I don't want to install Haskell
46 |
47 | All credit for this solution goes to [Radon](https://github.com/raxod502) and
48 | [Radian](https://radian.codes/) for creating and hosting Riju.
49 |
50 | First, open up either `call-by-push-block.hs` or
51 | `call-by-push-block-no-buffering.hs` and copy the source code.
52 |
53 | Then, go to [https://riju.codes/haskell](https://riju.codes/haskell).
54 |
55 | Paste the code and hit Run.
56 |
57 | You'll be able to play the game in the terminal on the right side.
58 |
59 | ### More details
60 |
61 | See the [Running section](#running) for more details.
62 |
63 | ## The cast
64 |
65 | - `λ`: The player character.
66 | - `o`: A block you can push.
67 | - `_`: The hole you need to push a block into.
68 | - Joined by several others!
69 |
70 | ## Scoring
71 |
72 | - Your score is displayed beneath the level number, starting at 1.
73 | - It increments for every move and undo you make and resets whenever you
74 | reset the level.
75 | - A lower score is better, except for a score of 0 which indicates an
76 | incompleted level.
77 |
78 | ## Controls in detail
79 |
80 | Note that you need to press Enter in order to make a move.
81 | - Movement: wasd
82 | - w: up
83 | - s: down
84 | - a: left
85 | - d: right
86 | - Reset: x
87 | - Resets the level. Also resets your score.
88 | - Undo: u
89 | - Undoes one move. This feature is added for convenience since moves must
90 | be sent using the Enter key (and thus it takes longer to get back where
91 | you were if you make a mistake) and incurs a small score penalty.
92 | - Additional notes
93 | - When prompted with `↩`, press Enter to continue.
94 | - Technically, all keys map to a control. Try to avoid pressing an
95 | unlabeled key as you can accidentally skip a level this way.
96 |
97 |
98 | ## Hints
99 | ***WARNING**: Do not read this in plaintext, as the hints are "hidden" using
100 | `` tags. Read the comments in `call-by-push-block.hs` for rot-13
101 | enciphered hints.
102 |
103 | I recommend revealing them in order until you find one that helps. If you
104 | are completely stuck on a level, there is a level skip code at the end.
105 |
106 | - Levels 1-5
107 | - Spoiler
You can direct the player character off
108 | the grid. This will require you to reset in order to beat the
109 | level.Spoiler
The hash is a static obstacle. Like a
111 | hole, it cannot be moved or passed through. You also cannot push blocks into
112 | it.Spoiler
You can push multiple blocks at a
114 | time.Spoiler
You can push blocks off of the grid. Be
116 | careful not to push a block you need off the grid.Spoiler
You need an empty tile adjacent to a
118 | block in order to push it. For example, to push a block down, it needs an
119 | empty tile above it. Keep this in mind even for later levels since it will
120 | allow you to identify holes that are inaccessible to certain
121 | blocks.Spoiler
The first hint is no longer true: there
124 | are conditions where pushing a player character off the grid is necessary.
125 | Remember: you only need to push a block into each hole.Spoiler
The order you try things in often
127 | matters. Sometimes you may have the right idea but wrong execution
128 | order.Spoiler
Reset or undo early if you realize you
130 | are in an unwinnable state. A quick trick to determine whether you are in
131 | one is to count the number of remaining holes and check if there is a block
132 | that can be pushed into each. Refer also to the last hint of the previous
133 | section.Spoiler
The plus is a tile that destroys both
136 | player characters and blocks alike. When a block is pushed into it or a
137 | player character moves into it, both the plus and the object encountering it
138 | are replaced with an empty tile.Spoiler
Take advantage of hashes or holes to move
140 | some player characters will keeping others stationary.Spoiler
Elaborating on the above hint, you will
142 | find that some things which seem impossible are only so because your player
143 | characters are not coordinated in space properly. Sometimes you need to
144 | coordinate them by moving one and keeping another stationary. Other times
145 | they will be separated in an unwinnable state.Spoiler
Type "Cheat Code" (case sensitive) and
148 | press enter to skip the level. This will confer a score of 0, indicating the
149 | level was skipped. If you are playing on the unbuffered version, just typing
150 | the first letter will suffice.