Mailing List Archive: Re: Parse surprise

[REBOL] Re: Parse surprise

From: lmecir:mbox:vol:cz at: 18-Jan-2003 11:18


Hi Romano,

would you like to have something like PE?

    pe/pe "" [any (pe/ret "done")] ; == "done"

----- Original Message -----
From: "Romano Paolo Tenca"

> I should like to have a method to stop a parse rule inside paren code and
> reurn a value like true or false (or something else).

The source of PE:

pe: make object! [
    pe: function [
        "Parses a series according to rules."
        input [series!] "Input series to parse"
        rules [block! string! none!] "Rules to parse by"
        /all "Parses all chars including spaces."
        /case "Uses case-sensitive comparison."
    ] [value] [
        res?: false
        either rebol/words/all [
            error? value: try [
                apply/r/a :parse compose [
                    (either all ['all] [])
                    (either case ['case] [])
                ] reduce [input rules]
            ]
            res?
        ] [
            res?: false
            return get/any 'res
        ] [value]
    ]
    res?: false
    res: none
    ret: func [
        value [any-type!]
    ] [
        res?: true
        error? set/any 'res get/any 'value
        make error! ""
    ]
]