Difference between revisions of "HXT/Practical/Ebay1"

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deep f = f `orElse` (getChildren >>> deep f) -- deep redefinition to allow a broader signature
 
deep f = f `orElse` (getChildren >>> deep f) -- deep redefinition to allow a broader signature
   
split = map (dropWhile p) . groupBy (const (not . p)) where p = (=='/')
 
  +
split "" = []
  +
split xs = a : split (drop 1 b) where (a,b) = break (=='/') xs
  +
 
through = (getChildren >>>) . foldr1 (/>). map hasName . split
 
through = (getChildren >>>) . foldr1 (/>). map hasName . split
 
-- contains = (getChildren >>>). foldr1 (</). (map hasName)
 
-- contains = (getChildren >>>). foldr1 (</). (map hasName)

Revision as of 06:38, 21 August 2007

{-# LANGUAGE Arrows, NoMonomorphismRestriction, ParallelListComp #-} module Main where import Text.XML.HXT.Arrow hiding (deep) import Data.List (nub,sort,isPrefixOf,transpose,groupBy) deep f = f `orElse` (getChildren >>> deep f) -- deep redefinition to allow a broader signature split "" = [] split xs = a : split (drop 1 b) where (a,b) = break (=='/') xs through = (getChildren >>>) . foldr1 (/>). map hasName . split -- contains = (getChildren >>>). foldr1 (</). (map hasName) mkReport = mkelem "p" [] . map constA {- The datas we are munging is unstructured - Every feedback is spanned on two contigous rows of a big table - We cannot catch the all data in a match, so we use listA to have the two single-row lists - and then zip them to rebuild the data. -} getFeedbackAndValue = hasName "table" >>> hasAttrValue "class" (=="fbOuter") /> hasName "tbody" >>> proc table -> do feedbacks <- listA (through "tr/td/img") -< table values <- listA (through "tr/td" /> hasText (isPrefixOf "EUR")) -< table catA (map mkReport $ transpose [values,feedbacks]) -<< () src = "feedback.example.html" dst = "feedback.report.html" unicoding= (a_encoding, unicodeString) nowarnings = (a_issue_warnings,v_0) main = runX ( readDocument [(a_parse_html, v_1),unicoding,nowarnings] src >>> root [] [deep getFeedbackAndValue] >>> writeDocument [(a_indent,v_1),unicoding,nowarnings] dst )

Note that the use of groupBy in defining 'split' abuses the implementation details of 'groupBy' which are not guaranteed by its definition in the Haskell 98 standard report.