Quoter

language-python/language-python.cabal

@@ -33,7 +33,9 @@ Library
       array >= 0.4 && < 0.6,
       transformers >= 0.3 && < 0.6,
       monads-tf == 0.1.*,
-      utf8-string >= 1 && < 2
+      utf8-string >= 1 && < 2,
+      template-haskell >=2.10
+
    build-tools: happy, alex
    exposed-modules:
       Language.Python.Common
@@ -45,6 +47,7 @@ Library
       Language.Python.Common.PrettyToken
       Language.Python.Common.AST
       Language.Python.Common.PrettyAST
+      Language.Python.Common.Quoter
       Language.Python.Version3
       Language.Python.Version3.Parser
       Language.Python.Version3.Lexer

language-python/src/Language/Python/Common.hs

@@ -27,7 +27,9 @@ module Language.Python.Common (
    -- * Parse errors
    module Language.Python.Common.ParseError,
    -- * Pretty printing parse errors
-   module Language.Python.Common.PrettyParseError -- this export is for Haddock
+   module Language.Python.Common.PrettyParseError, -- this export is for Haddock
+   -- * Quasiquoter
+   module Language.Python.Common.Quoter
   ) where
 
 import Language.Python.Common.Pretty 
@@ -38,3 +40,4 @@ import Language.Python.Common.PrettyToken ()
 import Language.Python.Common.SrcLocation 
 import Language.Python.Common.PrettyParseError ()
 import Language.Python.Common.ParseError
+import Language.Python.Common.Quoter

language-python/src/Language/Python/Common/Quoter.hs

@@ -0,0 +1,106 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      : Language.Python.Common.Quoter
+-- License     : BSD-style
+-- Stability   : experimental
+-- Portability : ghc
+--
+-- Simple quasiquoters for converting python code into haskell expressions or patterns (it doesn't work for declarations and types). 
+-- Multi-line python quotations must be left aligned in the file. 
+-- Examples, that will yield :
+-- @
+-- binOpExpr = [pyExpr|x+y|]
+-- 
+-- [retStmt] = [pyStmt|return z|]
+-- 
+-- [py2Print] = [py2] = [py2Stmt|print somelist[1], "Hej there!"|]
+-- 
+-- pyMod = [pyModule|
+-- import something
+-- 
+-- def fun(a,b):
+--     c = a+b
+--     print(c)
+-- |]
+-- @
+-- Caution: This checks only for syntax of single quotes, not types or scopes or combinations of quotes.
+-- For example nothing keeps you from appending py2Print to pyMod. So this can be used to generate code,
+-- but checking validity is up to you.
+-----------------------------------------------------------------------------
+
+module Language.Python.Common.Quoter (
+   -- * Quoting python 3.x modules
+   pyModule,
+   -- * Quoting python 3.x statements
+   pyStmt,
+   -- * Quoting python 3.x expressions
+   pyExpr,
+   -- * Quoting python 2.x modules
+   py2Module,
+   -- * Quoting python 2.x statements
+   py2Stmt,
+   -- * Quoting python 2.x expressions
+   py2Expr) where
+
+import Language.Python.Version3.Parser as V3
+import Language.Python.Version2.Parser as V2
+
+import Language.Python.Common.Token as Token
+import Language.Python.Common.ParserMonad ( ParseError)
+import Data.Data ( Data )
+
+import Language.Haskell.TH 
+import Language.Haskell.TH.Quote ( QuasiQuoter(..), dataToExpQ, dataToPatQ )
+
+quoter :: (Data a) => (String -> String -> Either ParseError (a, [Token]))-> QuasiQuoter
+quoter parser = QuasiQuoter
+                { quoteExp = parseAndExpQuote parser 
+                , quotePat = parseAndPatQuote parser
+                , quoteDec = error "this quasiquoter does not support declarations"
+                , quoteType = error "this quasiquoter does not support types"
+                }
+
+
+parseAndExpQuote:: (Data a) => (String -> String -> Either ParseError (a, [Token])) -> String -> Q Exp
+parseAndExpQuote parser content = do 
+  parseResult <- apply parser "" content
+  dataToExpQ (const Nothing) parseResult 
+
+parseAndPatQuote:: (Data a) => (String -> String -> Either ParseError (a, [Token]))-> String -> Q Pat
+parseAndPatQuote parser content = do 
+  parseResult <- apply parser "" content
+  dataToPatQ (const Nothing) parseResult 
+
+apply:: (Monad m, MonadFail m) => 
+        (String -> String -> Either ParseError (a, [Token])) 
+         -> String -> String -> m a
+apply parser name content  = 
+  case parser content name of
+    Left parseError -> fail $ show parseError
+    Right (subAST, comments) -> return subAST
+
+
+pyModule :: QuasiQuoter
+pyModule = quoter V3.parseModule
+
+
+pyStmt :: QuasiQuoter
+pyStmt = quoter V3.parseStmt
+
+
+pyExpr:: QuasiQuoter
+pyExpr = quoter V3.parseExpr
+
+
+py2Module :: QuasiQuoter
+py2Module = quoter V2.parseModule
+
+
+py2Stmt :: QuasiQuoter
+py2Stmt = quoter V2.parseStmt
+
+
+py2Expr:: QuasiQuoter
+py2Expr = quoter V2.parseExpr
+
+

language-python/src/Language/Python/Version3.hs

@@ -23,8 +23,8 @@ module Language.Python.Version3 (
    -- * The parser
    module Language.Python.Version3.Parser, 
    -- * The lexer
-   module Language.Python.Version3.Lexer 
+   module Language.Python.Version3.Lexer
    ) where
 
 import Language.Python.Version3.Parser 
-import Language.Python.Version3.Lexer 
+import Language.Python.Version3.Lexer