Basic repr + some stubs
Getty Ritter
9 years ago
1 | -- | Contains the type of atoms that Common Lisp understands, as | |
2 | -- well as the built-in reader macros that Common Lisp provides. | |
3 | -- Given a Common Lisp source file that contains no extra reader | |
4 | -- macro definitions, this module should successfully parse and | |
5 | -- desugar even quoted lists and vector literals. | |
6 | ||
7 | module Data.SExpression.CommonLisp where | |
8 | ||
9 | data Atom | |
10 | = Symbol Text | |
11 | | String Text | |
12 | | Integer Int | |
13 | | True | |
14 | deriving (Eq, Show, Read) | |
15 | ||
16 | parseSexpr :: Text -> Either SExprError |
1 | module Data.SExpression.General where |
1 | {-# LANGUAGE PatternSynonyms #-} | |
2 | ||
3 | module Data.SExpression.Repr.Rich | |
4 | ( pattern List | |
5 | , pattern DotList | |
6 | , pattern Atom | |
7 | ) where | |
8 | ||
9 | import Data.SExpression.Repr as R | |
10 | ||
11 | pattern List xs = R.RSList xs | |
12 | pattern DotList xs = R.RSDotted xs | |
13 | pattern Atom a = R.RSAtom a |
1 | {-# LANGUAGE PatternSynonyms #-} | |
2 | ||
3 | module Data.SExpression.Repr.Rich | |
4 | ( pattern List | |
5 | , pattern Atom | |
6 | ) where | |
7 | ||
8 | import Data.SExpression.Repr as R | |
9 | ||
10 | pattern List xs = R.WFSList xs | |
11 | pattern Atom a = R.WFSAtom a |
1 | module Data.SExpression.Repr | |
2 | ( SExpr(..) | |
3 | , RichSExpr(..) | |
4 | , toRich | |
5 | , fromRich | |
6 | , WellFormedSExpr(..) | |
7 | , toWellFormed | |
8 | , fromWellFormed | |
9 | ) where | |
10 | ||
11 | -- | All S-Expressions can be understood as a sequence | |
12 | -- of @cons@ cells (represented here by @SCons@), the | |
13 | -- empty list @nil@ (represented by @SNil@) or an | |
14 | -- @atom@. | |
15 | data SExpr atom | |
16 | = SCons (SExpr atom) (SExpr atom) | |
17 | | SAtom atom | |
18 | | SNil | |
19 | deriving (Eq, Show, Read) | |
20 | ||
21 | -- | Sometimes, the cons-based interface is too low | |
22 | -- level, and we'd rather have the lists themselves | |
23 | -- exposed. In this case, we have @RSList@ to | |
24 | -- represent a well-formed cons list, and @RSDotted@ | |
25 | -- to represent an improper list of the form | |
26 | -- @(a b c . d)@. | |
27 | data RichSExpr atom | |
28 | = RSList [RichSExpr atom] | |
29 | | RSDotted [RichSExpr atom] atom | |
30 | | RSAtom atom | |
31 | deriving (Eq, Show, Read) | |
32 | ||
33 | toRich :: SExpr atom -> RichSExpr atom | |
34 | toRich (SAtom a) = RSAtom a | |
35 | toRich (SCons x xs) = go xs [toRich x] | |
36 | where go (SAtom a) rs = RSDotted rs a | |
37 | go SNil rs = RSList rs | |
38 | go (SCons x xs) rs = go xs (toRich x:rs) | |
39 | ||
40 | fromRich :: RichSExpr atom -> SExpr atom | |
41 | fromRich (RSAtom a) = SAtom a | |
42 | fromRich (RSList xs) = foldr SCons SNil (map fromRich xs) | |
43 | fromRich (RSDotted xs x) = foldr SCons (SAtom x) (map fromRich xs) | |
44 | ||
45 | -- | A well-formed s-expression is one which does not | |
46 | -- contain any dotted lists. This means that not | |
47 | -- every value of @SExpr a@ can be converted to a | |
48 | -- @WellFormedSExpr a@, although the opposite is | |
49 | -- fine. | |
50 | data WellFormedSExpr atom | |
51 | = WFSList [WellFormedSExpr atom] | |
52 | | WFSAtom atom | |
53 | deriving (Eq, Show, Read) | |
54 | ||
55 | -- | This will be @Nothing@ is the argument contains an | |
56 | -- improper list. It should hold that | |
57 | toWellFormed :: SExpr atom -> Maybe (WellFormedSExpr atom) | |
58 | toWellFormed (SAtom a) = Just (WFSAtom a) | |
59 | toWellFormed (SCons x xs) = do | |
60 | x' <- toWellFormed x | |
61 | go xs [x'] | |
62 | where go (SAtom a) rs = Nothing | |
63 | go SNil rs = Just (WFSList rs) | |
64 | go (SCons x xs) rs = do | |
65 | x' <- toWellFormed x | |
66 | go xs (x':rs) | |
67 | ||
68 | -- | Convert a WellFormedSExpr back into a SExpr. | |
69 | fromWellFormed :: WellFormedSExpr atom -> SExpr atom | |
70 | fromWellFormed (WFSAtom a) = SAtom a | |
71 | fromWellFormed (WFSList xs) = | |
72 | foldr SCons SNil (map fromWellFormed xs) |
1 | Copyright (c) 2014, Getty Ritter | |
2 | ||
3 | All rights reserved. | |
4 | ||
5 | Redistribution and use in source and binary forms, with or without | |
6 | modification, are permitted provided that the following conditions are met: | |
7 | ||
8 | * Redistributions of source code must retain the above copyright | |
9 | notice, this list of conditions and the following disclaimer. | |
10 | ||
11 | * Redistributions in binary form must reproduce the above | |
12 | copyright notice, this list of conditions and the following | |
13 | disclaimer in the documentation and/or other materials provided | |
14 | with the distribution. | |
15 | ||
16 | * Neither the name of Getty Ritter nor the names of other | |
17 | contributors may be used to endorse or promote products derived | |
18 | from this software without specific prior written permission. | |
19 | ||
20 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
21 | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
22 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
23 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
24 | OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
25 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
26 | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
27 | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
28 | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
29 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
30 | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
1 | -- Initial s-expression.cabal generated by cabal init. For further | |
2 | -- documentation, see http://haskell.org/cabal/users-guide/ | |
3 | ||
4 | name: s-expression | |
5 | version: 0.1.0.0 | |
6 | -- synopsis: | |
7 | -- description: | |
8 | license: BSD3 | |
9 | license-file: LICENSE | |
10 | author: Getty Ritter | |
11 | maintainer: gdritter@galois.com | |
12 | -- copyright: | |
13 | category: Data | |
14 | build-type: Simple | |
15 | -- extra-source-files: | |
16 | cabal-version: >=1.10 | |
17 | ||
18 | library | |
19 | -- exposed-modules: | |
20 | -- other-modules: | |
21 | -- other-extensions: | |
22 | build-depends: base >=4.7 && <4.8 | |
23 | -- hs-source-dirs: | |
24 | default-language: Haskell2012⏎ |