:: with-sequence-parser ( sequence-parser quot -- seq/f )
sequence-parser n>> :> n
sequence-parser quot call [
- n sequence-parser (>>n) f
+ n sequence-parser n<< f
] unless* ; inline
: offset ( sequence-parser offset -- char/f )
sequence-parser [ growing length - 1 + ] change-n drop
! sequence-parser advance drop
] [
- saved sequence-parser (>>n)
+ saved sequence-parser n<<
f
] if ;