My implementation:

[link:fabiogaluppo.spaces.live.com]

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#light

open System.IO

open System.Text.RegularExpressions

let read_line file =

seq{ use r = new StreamReader( File.OpenRead( file ) )

while not r.EndOfStream do yield r.ReadLine() }

let wide_finder filename pattern =

let reg_ex = Regex( pattern, RegexOptions.Compiled ||| RegexOptions.CultureInvariant )

let select = Seq.iter

let where = Seq.filter

let orderby = Seq.orderBy

let groupby = Seq.groupBy

let map = Seq.map

let len = IEnumerable.length

let from enum_seq = enum_seq |> map ( fun line -> reg_ex.Match( line ) )

(* execute query *)

from ( read_line( filename ) )

|> where ( fun rmatch -> rmatch.Success )

|> groupby ( fun rmatch -> rmatch.Value )

|> orderby ( fun ( key, _ ) -> key )

|> select ( fun ( key, matches ) -> printfn "%s %d" key ( matches |> len ) )

let main =

wide_finder Sys.argv.(1) (* <- first cmdline arg *) "GET /ongoing/When/\d\d\dx/(\d\d\d\d/\d\d/\d\d/[^ .]+)"

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WF discussion:

[link:www.tbray.org]