ERROR: subseq-expected-but-got-eof n string expected ;
:: slice-til-string ( n string search -- n' string payload end-string )
- n string search subsequence-starts-from :> n'
+ n string search subseq-index-from :> n'
n' [ n string search subseq-expected-but-got-eof ] unless
n' search length + string
n n' string ?<slice>