play.xtl

1⍝!/usr/bin/env xetal
2⍝# 2048 at the terminal: slide the tiles with a (left), d (right), w (up)
3⍝# or s (down), then Enter; q stops. Equal tiles that meet merge; make a 2048.
4⍝# The board is printed as X_eTaL prints a matrix (0 is an empty
5⍝# square). The rules are those of Twenty48.xtl.
6ᵗ⁼u̲se< "Twenty48"
7ᵖ⁼u̲se< "Play"
8said ← p̲rint! "2048: A LEFT, D RIGHT, W UP, S DOWN"
9
10⍝# A direction (1 left, 2 right, 3 up, 4 down) from the first of a d w s
11⍝# on the line, 0 for q; anything else is asked for again.
12ᵘa̲sk ← { s →
13  k ← "MOVE (A D W S, Q TO STOP) ?" ᵖl̲etter "adwsADWSqQ"
14  k ≤ 8 ? 1 + (k − 1) m̲od 4
15  k ≤ 10 ? 0◆ ᵘa̲sk s
16}
17⍝# A turn: the score and board, a move, until the game ends.
18ᵘt̲urn ← { s →
19  said ← p̲rint! ""
20  said ← p̲rint! @ f̲ormat< "SCORE {t:s_core s}"
f̲ormat< expands to("SCORE " c̲at (f̲ormat (ᵗs̲core s)))
21  shown ← p̲rint! ᵗb̲oard s
22  1 = ᵗs̲tatus s ? @ f̲ormat< "2048! YOU WIN WITH {t:s_core s}"
f̲ormat< expands to("2048! YOU WIN WITH " c̲at (f̲ormat (ᵗs̲core s)))
23  2 = ᵗs̲tatus s ? @ f̲ormat< "NO MOVES LEFT. SCORE {t:s_core s}"
f̲ormat< expands to("NO MOVES LEFT. SCORE " c̲at (f̲ormat (ᵗs̲core s)))
24  d ← ᵘa̲sk s
25  0 = d ? @ f̲ormat< "STOPPED WITH SCORE {t:s_core s}"
f̲ormat< expands to("STOPPED WITH SCORE " c̲at (f̲ormat (ᵗs̲core s)))
26  next ← s ᵗm̲ove d
27  next m̲atch s ? ᵘt̲urn ᵘs̲tuck s◆ ᵘt̲urn next
28}
29ᵘs̲tuck ← { s →
30  said ← p̲rint! "NOTHING MOVES THAT WAY."
31  s
32}
33ᵘt̲urn ᵗn̲ew 0