smalltalk: Conway Life + dynamic-array literal {…}; classic corpus complete

lib/smalltalk/tests/programs/life.st

@@ -0,0 +1,66 @@
+"Conway's Game of Life — 2D grid stepped by the standard rules:
+   live with 2 or 3 neighbours stays alive; dead with exactly 3 becomes alive.
+ Classic-corpus program for the Smalltalk-on-SX runtime. The canonical
+ 'glider gun' demo (~36 cells, period-30 emission) is correct but too slow
+ to verify on the spec interpreter without JIT — block, blinker, glider
+ cover the rule arithmetic and edge handling."
+
+Object subclass: #Life
+  instanceVariableNames: 'rows cols cells'!
+
+!Life methodsFor: 'init'!
+rows: r cols: c
+  rows := r. cols := c.
+  cells := Array new: r * c.
+  1 to: r * c do: [:i | cells at: i put: 0].
+  ^ self! !
+
+!Life methodsFor: 'access'!
+rows ^ rows!
+cols ^ cols!
+
+at: r at: c
+  ((r < 1) or: [r > rows]) ifTrue: [^ 0].
+  ((c < 1) or: [c > cols]) ifTrue: [^ 0].
+  ^ cells at: (r - 1) * cols + c!
+
+at: r at: c put: v
+  cells at: (r - 1) * cols + c put: v.
+  ^ v! !
+
+!Life methodsFor: 'step'!
+neighbors: r at: c
+  | sum |
+  sum := 0.
+  -1 to: 1 do: [:dr |
+    -1 to: 1 do: [:dc |
+      ((dr = 0) and: [dc = 0]) ifFalse: [
+        sum := sum + (self at: r + dr at: c + dc)]]].
+  ^ sum!
+
+step
+  | next |
+  next := Array new: rows * cols.
+  1 to: rows * cols do: [:i | next at: i put: 0].
+  1 to: rows do: [:r |
+    1 to: cols do: [:c |
+      | n alive lives |
+      n := self neighbors: r at: c.
+      alive := (self at: r at: c) = 1.
+      lives := alive
+                 ifTrue: [(n = 2) or: [n = 3]]
+                 ifFalse: [n = 3].
+      lives ifTrue: [next at: (r - 1) * cols + c put: 1]]].
+  cells := next.
+  ^ self!
+
+stepN: n
+  n timesRepeat: [self step].
+  ^ self! !
+
+!Life methodsFor: 'measure'!
+livingCount
+  | sum |
+  sum := 0.
+  1 to: rows * cols do: [:i | (cells at: i) = 1 ifTrue: [sum := sum + 1]].
+  ^ sum! !