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|
-- |
-- Module : Data.ASN1.Stream
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : experimental
-- Portability : unknown
--
module Data.ASN1.Stream
( ASN1Repr
, getConstructedEnd
, getConstructedEndRepr
) where
import Data.ASN1.Types
import Data.ASN1.Types.Lowlevel
{- associate a list of asn1 event with an ASN1 type.
- it's sometimes required to know the exact byte sequence leading to an ASN1 type:
- eg: cryptographic signature -}
type ASN1Repr = (ASN1, [ASN1Event])
getConstructedEnd :: Int -> [ASN1] -> ([ASN1],[ASN1])
getConstructedEnd _ xs@[] = (xs, [])
getConstructedEnd i ((x@(Start _)):xs) = let (yz, zs) = getConstructedEnd (i+1) xs in (x:yz,zs)
getConstructedEnd i ((x@(End _)):xs)
| i == 0 = ([], xs)
| otherwise = let (ys, zs) = getConstructedEnd (i-1) xs in (x:ys,zs)
getConstructedEnd i (x:xs) = let (ys, zs) = getConstructedEnd i xs in (x:ys,zs)
getConstructedEndRepr :: [ASN1Repr] -> ([ASN1Repr],[ASN1Repr])
getConstructedEndRepr = g
where g [] = ([], [])
g (x@(Start _,_):xs) = let (ys, zs) = getEnd 1 xs in (x:ys, zs)
g (x:xs) = ([x],xs)
getEnd :: Int -> [ASN1Repr] -> ([ASN1Repr],[ASN1Repr])
getEnd _ [] = ([], [])
getEnd 0 xs = ([], xs)
getEnd i ((x@(Start _, _)):xs) = let (ys, zs) = getEnd (i+1) xs in (x:ys,zs)
getEnd i ((x@(End _, _)):xs) = let (ys, zs) = getEnd (i-1) xs in (x:ys,zs)
getEnd i (x:xs) = let (ys, zs) = getEnd i xs in (x:ys,zs)
|
