Boggle Solver in J

reading and querying word lists

WL =: ' ' ,.~^:2 (_1{.a.),~];._2@(1!:1)@<
NL =: ''$~0,{: $ PF=: WL'collins-prefixes.txt'[EX=: WL'collins-words.txt'
L =: {:@$ - +/"1@(' '&=)
W =: (-:"1 EX {~ EX&I.) @: (NL&,)
P =: (-:"1 PF {~ PF&I.) @: (NL&,)

graphs for boards & expansions for paths

G =: [: <@-.&_1"1 @ |: [: ;"_1 (<:3 3#:4-.~i.9) |.!._1 i.
A =: [ ,"_ 0/ [ -.~ ] {::~ {:@:[

handling Qs

QU =: ('U'(1+[:I.'QQ'E.])}(#~1+'Q'&=)) ^: ('Q'&e.)
Q =: (QU :. (#~ [: -. _1 |. 'QU'&E.))"1

the search

E =: {{ ([: (#~ P @: Q @ ({&u)) [: ; <@(A&v)"1) ^: (0<#) &. > }}
S =: {{ (,y) E (G$y) ^: a: <,.i.#,y }}
B =: {{ (\: L) /:~ (#~ W) ~. Q ; ({&(,y)) &.> S y }}

generating boards

BW =: Q (#~ 10 < L) EX
SC =: 0 0 0 1 1 2 3 5 8 13 {~ 8 <. #
RW =: {{try. (({~ ?@#) @ A&(G x)) ^: (<:y) ? */ x catch. x RW y end.}}
RB =: 4 : 0
 assert. (#y=.Q^:_1 y) <: n=.*/x
 x $ toupper (y,a.{~65+?(n-#y)$26) ((p-.~i.n),~p=.x RW #y)} n $ y
)
RL =: {{ y RB > ({~ ?@#) BW }}

z defs

shake_z_ =: RL_joggle_
board_z_ =: RB_joggle_
boggle_z_ =: B_joggle_
score_z_ =: SC_joggle_