check-optional* ( result -- result )

Vocabulary

peg.private

Inputs

result

an object

Outputs

result

an object

Definition

USING: accessors arrays kernel peg ;

IN: peg.private

: check-optional* ( result -- result )
    [
        input-slice swap ast>> dup ignore =
        [ drop { } clone ] [ 1array ] if
    ] [ input-slice f ] if* <parse-result> ;