501ca35...master · syntax

git.iko.soy/syntax

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3 files changed+21−8

since splitsnapshots

unifiedsplit

Data/Syntax.hs+4 Data/Syntax/Combinator.hs+10−1 syntax.cabal+7−7

Data/Syntax.hs+4

@@ -166,6 +166,10 @@ instance Syntax syn => Syntax (ReaderCT env syn) where

166166 takeWhile1 = clift . takeWhile1

167167 takeTill = clift . takeTill

168168 takeTill1 = clift . takeTill1

169+ vecN n e = ReaderCT $ vecN n . runReaderCT e

170+ ivecN n e = ReaderCT $ ivecN n . runReaderCT e

171+ uvecN n e = ReaderCT $ uvecN n . runReaderCT e

172+ uivecN n e = ReaderCT $ uivecN n . runReaderCT e

169173

170174-- | Execute a computation in an isolated context.

171175--

Data/Syntax/Combinator.hs+10−1

@@ -26,6 +26,9 @@ module Data.Syntax.Combinator

2626 sepBy,

2727 sepBy1,

2828

29+ -- * Arrowized combinators.

30+ takeArr,

31+

2932 -- * Vectors.

3033 vecNSepBy,

3134 ivecNSepBy,

@@ -48,10 +51,11 @@ import Control.Category.Structures

4851import Control.Lens

4952import Control.Lens.SemiIso

5053import Control.SIArrow

54+import qualified Data.MonoTraversable as Seq

5155import Data.Syntax

5256import qualified Data.Vector as V

5357import qualified Data.Vector.Unboxed as VU

54−import Prelude hiding (id, (.))

58+import Prelude hiding (id, (.), take)

5559

5660-- | One or zero occurences of @f@.

5761optional :: SIArrow cat => cat () a -> cat () (Maybe a)

@@ -89,6 +93,11 @@ sepBy v s = sepBy1 v s /+/ sipure _Empty

8993sepBy1 :: SIArrow cat => cat () a -> cat () () -> cat () [a]

9094sepBy1 v s = _Cons /$/ v /*/ (s */ sepBy1 v s /+/ sipure _Empty)

9195

96+-- | A string of given length.

97+takeArr :: Syntax syn => syn Int (Seq syn)

98+takeArr = sibind $ iso (\n -> constant n #>> take n)

99+ (\s -> constant (Seq.olength s) #>> take (Seq.olength s))

100+

92101-- | Constant size vector with separators.

93102--

94103-- @vecNSepBy n e sep@ describes a size @n@ vector with elements @e@ separated by @sep@.

syntax.cabal+7−7

@@ -4,9 +4,10 @@ synopsis: Reversible parsing and pretty-printing.

44description:

55 "syntax" allows you to write a single syntax description and instantiate is both as a parser and a pretty printer.

66 .

7− Syntax descriptions are written in applicative or arrow style. The library uses a custom hierarchy, provided by the

8− "semi-iso" package. Most of the time you will be using operators like '/$/' and '/*/', just like parser combinators.

9− When more power is needed - e.g. when the syntax depends on the parsed or printed value - you turn to arrows.

7+ Syntax descriptions are written in applicative or arrow style. The library uses a custom typeclass hierarchy, provided

8+ by the "semi-iso" package. Most of the time you will be using operators like '/$/', '/*/' and '/+/' (= '<|>'), just

9+ like parser combinators. When more power is needed - e.g. when the syntax depends on the parsed or printed value -

10+ you turn to arrows.

1011 .

1112 Semi-isomorphisms from "semi-iso" are the basic building block of syntax descriptions. I recommend reading

1213 the hackage page of "semi-iso" first, as it contains much more information.

@@ -19,11 +20,10 @@ description:

1920 Advanced formatting and parsing (for example indentation, haskell layout rule) is implemented as category transformers

2021 (similar to monad transformers). Currently only simple indentation is implemented (in "Data.Syntax.Indent") - basically

2122 a reader category transformer that tracks current indentation level. I plan on implementing Haskell layout rule in the

22− future (as a reusable transformer).

23+ future.

2324 .

24− Note that the library can work with both text and binary data. There are no binary combinators implemented - yet.

25− Alas, these are not only useful combinators missing! I will slowly but steadily implement them over time

26− (but these category transformers look so much more interesting for now ;).

25+ The library can work with both text and binary data. Alas, there are no binary combinators implemented yet.

26+ I will implement them when i have the time (but these category transformers look so much more interesting for now ;).

2727 .

2828 EXAMPLES! See @syntax-example@ and @syntax-example-json@ for examples.

2929 .