Difference between revisions of "Learning Haskell with Chess"
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===Learning targets=== |
===Learning targets=== |
||
*recapitulate Haskell types (keywords type and data, product and sum types) |
*recapitulate Haskell types (keywords type and data, product and sum types) |
||
| − | **Helium: |
+ | **Helium: equality and show functions (pattern matching) |
| − | **Haskell: |
+ | **Haskell: type classes (<hask>Show</hask>, <hask>Eq</hask>, <hask>deriving</hask> |
*pretty printing |
*pretty printing |
||
===Tasks=== |
===Tasks=== |
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| − | *Define data types that represent boards (<hask>Board</hask>), squares (<hask>Square</hask>), positions (<hask>Pos</hask>), pieces (<hask>Piece</hask>) and game states (<hask>State</hask>). |
+ | *Define data types that represent boards (<hask>Board</hask>), squares (<hask>Square</hask>), positions (<hask>Pos</hask>), pieces (<hask>Piece</hask>, supported by <hask>PieceColor</hask> and <hask>PieceType</hask>) and game states (<hask>State</hask>). |
| − | *Helium: Implement suited eq |
+ | **Helium: Implement suited eq and show functions. |
| + | **Haskell: Define/derive instances of <hask>Show</hask> and <hask>Eq</hask> |
||
*Implement a function <hask>prettyBoard::Board->String</hask>, that transforms a board into a clearly arranged string representation (human readable :-)). Support this function with auxiliary functions that pretty print pieces, squares, ... |
*Implement a function <hask>prettyBoard::Board->String</hask>, that transforms a board into a clearly arranged string representation (human readable :-)). Support this function with auxiliary functions that pretty print pieces, squares, ... |
||
*Define the initial board (<hask>initialBoard::Board</hask>), test prettyBoard with initialBoard. |
*Define the initial board (<hask>initialBoard::Board</hask>), test prettyBoard with initialBoard. |
||
Revision as of 08:33, 19 March 2007
This page is about learning Haskell using the board game Chess as a running example. The complete code can be found at http://www.steffen-mazanek.de/dateien/projekte/hsChess.zip.
Exercise 1 - data types
Learning targets
- recapitulate Haskell types (keywords type and data, product and sum types)
- Helium: equality and show functions (pattern matching)
- Haskell: type classes (
Show,Eq,deriving
- pretty printing
Tasks
- Define data types that represent boards (
Board), squares (Square), positions (Pos), pieces (Piece, supported byPieceColorandPieceType) and game states (State).- Helium: Implement suited eq and show functions.
- Haskell: Define/derive instances of
ShowandEq
- Implement a function
prettyBoard::Board->String, that transforms a board into a clearly arranged string representation (human readable :-)). Support this function with auxiliary functions that pretty print pieces, squares, ... - Define the initial board (
initialBoard::Board), test prettyBoard with initialBoard. - Implement a simple evaluation function
evalBoard::Board->Intas the difference of material on board (values: Pawn->1, Knight and Bishop->3, Queen->9, Rook->6, King->"infinity"=1000).
Exercise 2 - move generator
Learning targets
- list comprehension
- stepwise refinement
Tasks
Exercise 3 - gametree generation and minimax algorithm
Learning targets
- break code in modules
- complexity
- recursive data structures -> recursive algorithms
Tasks
- Define a data type that represents a game tree (
GameTree). - Roughly estimate the number of nodes of the gametree with depth 4.
- Define a function
play::Gametree->Int, that computes the value of a given game tree using the minimax Algorithm. - Implement the function
doMove::State->State, that choses the (best) next state.