with-sequence-parser ( ..a sequence-parser quot: ( ..a parser -- ..b obj/f ) -- ..b obj/f )

sequence-parser	a sequence-parser
quot	a quotation with stack effect ( ..a parser -- ..b obj/f )

Outputs

obj/f

an object or f

Word description
Saves the position of the parser and calls the quotation on it. If the quotation returns f the parser is rewound to the saved position.

See also
parse-sequence

Definition

USING: accessors kernel ;

IN: sequences.parser

:: with-sequence-parser
( ..a sequence-parser quot: ( ..a parser -- ..b obj/f ) -- ..b obj/f )
sequence-parser n>> :> n sequence-parser quot call
[ n sequence-parser n<< f ] unless* ; inline