如何通过应用于它们各自的第一个和第二个值的谓词过滤具有 (Int, Int) 值的元组列表？

Question

Suppose i have a list of tuples representing positions on a grid by their x and y values.

The tuples are defined as type Pos, a pair of Integer values.

The Board is further defined as a list of Pos.

type Pos = (Int, Int)

type Board = [Pos]

exampleBoard :: Board
exampleBoard = [(1, 1), (1, 2), (2, 2), (2, 3), (1, 3),
                (5, 1), (5, 2), (4, 2), (4, 1), (5, 3),
                (9, 10), (9, 11), (9, 12), (9, 13),
                (10, 10), (10, 11), (10, 12), (10, 13),
                (10, 20), (11, 20), (12, 20), (13, 20)]

The Board is ax*x grid, where you can always consider the known variables height and width having the same value. height = width = size

If the x or y value is not in a certain range (0<x<size || 0<y<size) I want the tuple removed.

Is there a simple way to filter the list as I describe? From searching for similar questions I have tried using library functions such as "break" and "span" to no success as of yet.

Answer 1

To test if a tuple (Int,Int) is in a given range, you can use the inRange function:

import Data.Ix (inRange)

inRange ((1,1),(10,10)) (5,5)                    -- True
inRange ((1,1),(10,10)) (11,6)                   -- False

filter (inRange ((1,1),(10,10))) [(5,5),(11,6)]  -- [(5,5)]