1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
{-# LANGUAGE DeriveDataTypeable, QuasiQuotes #-}
-----------------------------------------------------------------------------
-- |
-- Module : Text.StringTemplate.QQ
-- Copyright : (c) Sterling Clover 2009
-- License : BSD 3 Clause
-- Maintainer : s.clover@gmail.com
-- Stability : experimental
-- Portability : portable
--
-- This module provides stmp, a quasi-quoter for StringTemplate expressions.
-- Quoted templates are guaranteed syntactically well-formed at compile time,
-- and antiquotation (of identifiers only) is provided by backticks.
-- Usage: @ let var = [0,1,2] in toString [$stmp|($\`var\`; separator = ', '$)|] === \"(0, 1, 2)\"@
-----------------------------------------------------------------------------
module Text.StringTemplate.QQ (stmp) where
import qualified Language.Haskell.TH as TH
import Language.Haskell.TH.Quote
import Text.StringTemplate.Base
import qualified Data.Set as S
quoteTmplExp :: String -> TH.ExpQ
quoteTmplPat :: String -> TH.PatQ
stmp :: QuasiQuoter
stmp = QuasiQuoter {quoteExp = quoteTmplExp, quotePat = quoteTmplPat}
quoteTmplPat = error "Cannot apply stmp quasiquoter in patterns"
quoteTmplExp s = return tmpl
where
vars = case parseSTMPNames ('$','$') s of
Right (xs,_,_) -> xs
Left err -> fail $ show err
base = TH.AppE (TH.VarE (TH.mkName "Text.StringTemplate.newSTMP")) (TH.LitE (TH.StringL s))
tmpl = S.foldr addAttrib base $ S.fromList vars
addAttrib var = TH.AppE
(TH.AppE (TH.AppE (TH.VarE (TH.mkName "Text.StringTemplate.setAttribute"))
(TH.LitE (TH.StringL ('`' : var ++ "`"))))
(TH.VarE (TH.mkName var)))
|
