First version of 2048 in BQN

2048.bqn

@@ -0,0 +1,36 @@
+#!/usr/bin/env BQN
+# The game is controlled with the vim movement keys:
+# h: left, j: down, k: up, l: right
+# it needs a VT-100 compatible terminal
+
+Merge←{ # Merges a row of tiles to the right
+  moved←4⊸↑⌾⌽ 0⊸≠⊸/𝕩 # remove empty tiles to move the tiles as far as possible
+  m←⌽0∾˜(¬⊸∧`=˝˘)⌾⌽2↕moved # which tiles to merge
+  r←(⟨∞⟩){t←⊑m ⋄ m↩1↓m ⋄ t◶⟨𝕨∾𝕩,(¯1↓𝕨)∾𝕩+¯1⊑𝕨⟩@}˜´moved # Merge tiles
+  4⊸↑⌾⌽⌽∞⊸≠⊸/r # Resize the result
+}
+Step←>·Merge¨<˘   # Merges each row of the board
+Up←Step⌾(⌽⍉∘⌽)    # Each direction merges the board
+Down←Step⌾⍉       # by rotating it to the correct orientation, merging the rows and reversing the rotation
+Right←Step
+Left←Step⌾(⌽˘)    
+Spawn←{i←(•rand.Range∘≠⊑⊢)(0⊸= /○⥊ ↕∘≢)𝕩 ⋄ 2˙⌾(i⊸⊑) 𝕩} # Spawns a 2 at a random empty position
+Lose←Left∘Right∘Down∘Up⊸≡ # Losing condition, no moves change the board
+Win←∨´·∨˝2048⊸= #  Winning condition, 2048!
+
+board←Spawn 4‿4⥊0
+e←@+27
+•term.RawMode 1 # 
+•Out e∾"[?25l"∾e∾"[2J"∾e∾"[H" # Cursor to origin, hide it and clear screen
+{𝕤⋄
+    •Out e∾"[H" # Cursor to origin
+    •Out "Controls: h: left, j: down, k: up, l: right, q: quit"
+    •Show board 
+    key←•term.CharB @ # Read key
+    {𝕤⋄•Out e∾"[?12l"∾e∾"[?25h"⋄•Exit 0}⍟(key='q')@ # Quit key?
+    move←⊑(key="hjkl")/Left‿Down‿Up‿Right # Get movement function from the key
+    {𝕤⋄board↩Spawn∘Move 𝕩}⍟(Move⊸≢) board # Generate the next board if the move is valid
+    {𝕤⋄•Out "You win!" ⋄ •Exit 0}⍟Win board
+    {𝕤⋄•Out "You lose!" ⋄ •Exit 1}⍟Lose board
+}•_While_{𝕤⋄¬Lose board}@
+•Out e∾"[?12l"∾e∾"[?25h" # Restore the cursor