REBOL [ Title: "Attribute Values Extractor" File: %ave.r Author: [ "HY" ] Date: 9-Jan-2006 Purpose: "Extract attribute values from (HTML) tags" Library: [ level: 'intermediate domain: [http web] license: none Platform: 'all Tested-under: none Type: 'function Support: none ] Comment: { Here are two functions: ex-att1 and ex-att2. The first has some limitations, and will return the worng text for the ACTION attribute on the example tag herein. The second is usually a tiny bit faster than the first, but in some cases much slower (like in the default benchmark test further down in this document). But the ex-att2 function RETURNS THE RIGHT ATTRIBUTE VALUE. } ] ex-att1: func [str attr /local a b] [ a: parse str "<> ='" while [b: find a "" remove b] [] trim to-string select a attr ] ex-att2: func [str attr /local ] [ ; the following definition has to be inside this function since I do a comparison on 'attr attr-value-pair: [copy a attr-name eq copy v attr-value (either all [dbq = first v dbq = last v] [v: trim-quotes v] [if all [sgq = first v sgq = last v] [v: trim-quotes v]] if (trim attr) = (trim a) [return trim v]) any ws x: ] parse/all str [thru-ws any [attr-only | attr-value-pair ] to end] "" ] thru-ws: [thru #" " | thru tab | thru newline] ws: [#" " | tab | newline] to-ws: [to #" " | to newline | to tab] not-eq: complement charset reduce "=" not-eq-or-ws: complement charset reduce [newline tab #" " #"="] dbq: to-char {"} sgq: #"'" eq: [ any ws #"=" any ws ] attr-value: [ [ dbq [ thru dbq | to end ] ] | [ sgq [ thru sgq | to end ] ] | [ to-ws any ws | to end ] ] attr-name: [ some not-eq-or-ws ] attr-only: [copy a attr-name any ws [not-eq x: (x: back x) :x | end] ] trim-quotes: func [str] [ str: reverse next reverse str str: next str ] tag: <FORM METHOD = POST ACTION=index.php?id=2&plus=377.> print tt: now/precise loop 5110000 [ ex-att1 tag "action" ] print join "ex-att1 used " difference now/precise tt print "^/===^/" print tt: now/precise loop 5110000 [ ex-att2 tag "action" ] print join "ex-att2 used " difference now/precise tt halt