HeadacheによるBrain F*ckのソースコードだけどどっかの括弧が対応取れてなくてバグってる。あとジャンプ命令あたりも怪しい

bf.txt

let source	 : "+++++++++[>++++++++>+++++++++++>+++++<<<-]>.>++.+++++++..+++.>-.------------.<++++++++.--------.+++.------.--------.>+.\0"

let item	 : 
lambda n	->
lambda list -> 
if ( = n 0 ) 
then head list
else item ( - n 1 ) ( tail list )

let state	 :
lambda src	->
lambda ptr	->
lambda dat	->
lambda idx	-> ( src , ptr , dat , idx )

let move	 : 
lambda n	-> 
lambda s	-> ( item 0 s , ( + n ( item 1 s ) ) , item 2 s , item 3 s , item 4 s )

let increment :
lambda v	->
lambda n	->
lambda list	-> update list n ( + ( item n list ) v )

let decrement :
lambda v	->
lambda n	->
lambda list	-> update list n ( + ( item n list ) ( neg v ) )

let peek	 :
lambda s	-> ( item ( item 1 s ) ( item 0 s ) , s )

let read	 :
lambda s	-> ( item ( item 1 s ) ( item 0 s ) , move 1 s )

let back	 :
lambda s	-> ( item ( - ( item 1 s ) 1 ) ( item 0 s ) , move ( neg 1 ) s )

let jump_]	 : 
lambda s	-> 
if ( = ( item 0 ( read s ) ) "]" )
then ( item 1 ( read s ) )
else ( jump_] ( move 1 s ) )

let jump_[	 :
lambda s	-> 
if ( = ( item 0 ( back s ) ) "[" )
then ( item 1 ( back s ) )
else ( jump_[ ( move ( neg 1 ) s ) )

let command	 :
lambda x	->
if ( = ( head x ) "+" )  then command ( read ( increment 1 3  ( item 1 x ) ) ) else
if ( = ( head x ) "-" )  then command ( read ( decrement 1 3  ( item 1 x ) ) ) else
if ( = ( head x ) "<" )  then command ( read ( move ( neg 1 ) ( item 1 x ) ) ) else
if ( = ( head x ) ">" )  then command ( read ( move 1 ( item 1 x ) ) )		   else
if ( = ( head x ) "." )  then head ( command ( read ( item 1 x ) ) , puts ( item ( item 3 ( item 1 x ) ) ( item 2 ( item 1 x ) ) ) ) else
if ( = ( head x ) "[" )  then ( if ( = ( item ( item 3 ( item 1 x ) ) ( item 2 ( item 1 x ) ) ) 0 ) then ( command ( read ( jump_] ( item 1 x ) ) ) ) else ( command ( read ( item 1 x ) ) ) ) else
if ( = ( head x ) "]" )  then ( if ( = ( item ( item 3 ( item 1 x ) ) ( item 2 ( item 1 x ) ) ) 0 ) then ( command ( read ( item 1 x ) ) ) else ( command ( read ( jump_[ ( item 1 x ) ) ) ) ) else
if ( = ( head x ) "\0" ) then nil else
( command ( read ( item 1 x ) ) )

let memory	 :
lambda n	-> if ( = n 0 ) then 0 else cons 0 ( memory ( - n 1 ) )

let []	 : state source 0 ( memory 1000 ) 0 

let eval : command ( peek [] )

let main : puts ( eval )