at-most-n ( parser n -- parser' ) (original) (raw)

at-most-n ( parser n -- parser' )

Vocabulary
parser-combinators

Inputs

parser	an object
n	an object

Outputs

parser'	an object

Definition

USING: kernel math ;

IN: parser-combinators

: at-most-n ( parser n -- parser' )
dup zero?
[ 2drop epsilon ] [ 2dup exactly-n -rot 1 - at-most-n <|> ]
if ;