mw-engine/src/mw_engine/utils.clj

117 lines
4.3 KiB
Clojure

;; Utility functions needed by MicroWorld and, specifically, in the interpretation of MicroWorld rule.
(ns mw-engine.utils
(:require [clojure.math.combinatorics :as combo]))
(defn member?
"True if elt is a member of col."
[elt col] (some #(= elt %) col))
(defn in-bounds
"True if x, y are in bounds for this world (i.e., there is a cell at x, y)
else false.
* `world` a world as defined above;
* `x` a number which may or may not be a valid x coordinate within that world;
* `y` a number which may or may not be a valid y coordinate within that world."
[world x y]
(and (>= x 0)(>= y 0)(< y (count world))(< x (count (first world)))))
(defn get-cell
"Return the cell a x, y in this world, if any.
* `world` a world as defined above;
* `x` a number which may or may not be a valid x coordinate within that world;
* `y` a number which may or may not be a valid y coordinate within that world."
[world x y]
(cond (in-bounds world x y)
(nth (nth world y) x)))
(defn get-int
"Get the value of a property expected to be an integer from a map; if not present (or not an integer) return 0.
* `map` a map;
* `key` a symbol or keyword, presumed to be a key into the `map`."
[map key]
(cond map
(let [v (map key)]
(cond (and v (integer? v)) v
true 0))
true (throw (Exception. "No map passed?"))))
(defn population
"Return the population of this species in this cell. Currently a synonym for
`get-int`, but may not always be (depending whether species are later
implemented as actors)
* `cell` a map;
* `species` a keyword representing a species which may populate that cell."
[cell species]
(get-int cell species))
(defn get-neighbours
([world x y depth]
"Get the neighbours to distance depth of the cell at x, y in this world.
* `world` a world, as described in world.clj;
* `x` an integer representing an x coordinate in that world;
* `y` an integer representing an y coordinate in that world;
* `depth` an integer representing the distance from [x,y] that
should be searched."
(remove nil?
(map #(get-cell world (first %) (first (rest %)))
(remove #(= % (list x y))
(combo/cartesian-product
(range (- x depth) (+ x depth 1))
(range (- y depth) (+ y depth 1)))))))
([world cell depth]
"Get the neighbours to distance depth of this cell in this world.
* `world` a world, as described in world.clj;
* `cell` a cell within that world;
* `depth` an integer representing the distance from [x,y] that
should be searched."
(get-neighbours world (:x cell) (:y cell) depth))
([world cell]
"Get the immediate neighbours of this cell in this world
* `world` a world, as described in world.clj;
* `cell` a cell within that world."
(get-neighbours world cell 1)))
(defn get-neighbours-with-property-value
"Get the neighbours to distance depth of the cell at x, y in this world which
have this value for this property.
* `world` a world, as described in `world.clj`;
* `cell` a cell within that world;
* `depth` an integer representing the distance from [x,y] that
should be searched;
* `property` a keyword representing a property of the neighbours.
* `value` a value of that property"
([world x y depth property value]
(filter #(= (get % property) value) (get-neighbours world x y depth)))
([world cell depth property value]
(get-neighbours-with-property-value world (:x cell) (:y cell) depth
property value))
([world cell property value]
(get-neighbours-with-property-value world cell 1
property value)))
(defn get-neighbours-with-state
"Get the neighbours to distance depth of the cell at x, y in this world which
have this state.
* `world` a world, as described in `world.clj`;
* `cell` a cell within that world;
* `depth` an integer representing the distance from [x,y] that
should be searched;
* `state` a keyword representing a state in the world."
([world x y depth state]
(filter #(= (:state %) state) (get-neighbours world x y depth)))
([world cell depth state]
(get-neighbours-with-state world (:x cell) (:y cell) depth state))
([world cell state]
(get-neighbours-with-state world cell 1 state)))