1876b8c · text · git.iko.soy

git.iko.soy/text

Implement lazy length, and test it

--HG-- extra : convert_revision : f56356a3336b696fe26b0d1b4a970ca997b9483e

commit1876b8c33d3e4af9a0c22a38fd5436734e436973 authorBryan O'Sullivan <bos@serpentine.com> dateTue 3 Mar 2009, 00:33 (18 years ago) parentc88ba28

3 files changed+34−2

compare with master

unifiedsplit

Data/Text/Fusion.hs+13 Data/Text/Lazy.hs+15−2 tests/Properties.hs+6

Data/Text/Fusion.hs+13

@@ -39,6 +39,7 @@ module Data.Text.Fusion

3939 , init

4040 , null

4141 , length

42+ , length64

4243

4344 -- * Transformations

4445 , map

@@ -110,6 +111,7 @@ import qualified Data.List as L

110111import GHC.Exts (Int(..), (+#))

111112import Data.Bits ((.&.), shiftR)

112113import Data.Char (ord)

114+import Data.Int (Int64)

113115import Data.Text.Internal (Text(..))

114116import Data.Text.UnsafeChar (unsafeChr, unsafeWrite)

115117import qualified Data.Text.Array as A

@@ -313,6 +315,17 @@ length (Stream next s0 _len) = loop_length 0# s0

313315 Yield _ s' -> loop_length (z# +# 1#) s'

314316{-# INLINE[0] length #-}

315317

318+-- | /O(n)/ Returns the number of characters in a text.

319+length64 :: Stream Char -> Int64

320+length64 (Stream next s0 _len) = loop_length 0 s0

321+ where

322+ loop_length z s = case next s of

323+ Done -> z

324+ Skip s' -> loop_length z s'

325+ Yield _ s' -> let !z' = z + 1

326+ in loop_length z' s'

327+{-# INLINE[0] length64 #-}

328+

316329-- ----------------------------------------------------------------------------

317330-- * Stream transformations

318331

Data/Text/Lazy.hs+15−2

@@ -49,7 +49,7 @@ module Data.Text.Lazy

4949 , tail

5050 , init

5151 , null

52− -- , length

52+ , length

5353

5454 -- * Transformations

5555 -- , map

@@ -150,8 +150,9 @@ import Prelude (Char, Bool(..), Functor(..), Int, Maybe(..), String,

150150 Eq(..), Ord(..), (++),

151151 Read(..), Show(..),

152152 (&&), (||), (+), (-), (.), ($),

153− not, return, otherwise)

153+ fromIntegral, not, return, otherwise)

154154import qualified Prelude as P

155+import Data.Int (Int64)

155156import Data.String (IsString(..))

156157import qualified Data.Text as T

157158import qualified Data.Text.Fusion as S

@@ -295,6 +296,18 @@ null _ = False

295296 S.null (stream t) = null t

296297 #-}

297298

299+length :: Text -> Int64

300+length = foldlChunks go 0

301+ where go l t = l + fromIntegral (T.length t)

302+{-# INLINE [1] length #-}

303+

304+{-# RULES

305+"LAZY TEXT length -> fused" [~1] forall t.

306+ length t = S.length64 (stream t)

307+"LAZY TEXT length -> unfused" [1] forall t.

308+ S.length64 (stream t) = length t

309+ #-}

310+

298311-- | /O(1)/ Returns the last character of a 'Text', which must be

299312-- non-empty. Subject to array fusion.

300313last :: Text -> Char

tests/Properties.hs+6

@@ -136,7 +136,10 @@ prop_TL_init = init `eqEP` (unpackT . TL.init)

136136prop_S_null = null `eqP` S.null

137137prop_T_null = null `eqP` T.null

138138prop_TL_null = null `eqP` TL.null

139+prop_S_length = length `eqP` S.length

140+prop_S_length64 = length `eqP` (fromIntegral . S.length64)

139141prop_T_length = length `eqP` T.length

142+prop_TL_length = length `eqP` (fromIntegral . TL.length)

140143prop_T_map f = map f `eqP` (unpackT . T.map f)

141144prop_T_intercalate c = L.intercalate c `eq` (unpackT . T.intercalate (T.pack c) . map T.pack)

142145prop_T_intersperse c = L.intersperse c `eqP` (unpackT . T.intersperse c)

@@ -317,7 +320,10 @@ tests = [

317320 ("prop_S_null", mytest prop_S_null),

318321 ("prop_T_null", mytest prop_T_null),

319322 ("prop_TL_null", mytest prop_TL_null),

323+ ("prop_S_length", mytest prop_S_length),

324+ ("prop_S_length64", mytest prop_S_length64),

320325 ("prop_T_length", mytest prop_T_length),

326+ ("prop_TL_length", mytest prop_TL_length),

321327

322328 ("prop_T_map", mytest prop_T_map),

323329 ("prop_T_intercalate", mytest prop_T_intercalate),