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%
% (c) The AQUA Project, Glasgow University, 1996-1998
%
\section[PprEnv]{The @PprEnv@ type}
\begin{code}
module PprEnv (
PprEnv, --
BindingSite(..),
initPprEnv,
pCon, pBndr, pOcc, pSCC,
pTy, pTyVarO
) where
#include "HsVersions.h"
import {-# SOURCE #-} Const ( Con )
import Var ( Id, TyVar )
import CostCentre ( CostCentre )
import Type ( Type )
import Outputable
\end{code}
%************************************************************************
%* *
\subsection{Public interfaces for Core printing (excluding instances)}
%* *
%************************************************************************
\begin{code}
data PprEnv bndr
= PE {
pCon :: Con -> SDoc,
pSCC :: CostCentre -> SDoc,
pTyVarO :: TyVar -> SDoc, -- to print tyvar occurrences
pTy :: Type -> SDoc, -- to print types
pBndr :: BindingSite -> bndr -> SDoc, -- to print value binders
pOcc :: Id -> SDoc -- to print value occurrences
}
\end{code}
@BindingSite@ is used to tell the thing that prints binder what
language construct is binding the identifier.
\begin{code}
data BindingSite = LambdaBind | CaseBind | LetBind
\end{code}
\begin{code}
initPprEnv
:: Maybe (Con -> SDoc)
-> Maybe (CostCentre -> SDoc)
-> Maybe (TyVar -> SDoc)
-> Maybe (Type -> SDoc)
-> Maybe (BindingSite -> bndr -> SDoc)
-> Maybe (Id -> SDoc)
-> PprEnv bndr
-- you can specify all the printers individually; if
-- you don't specify one, you get bottom
initPprEnv p c tvo ty bndr occ
= PE (demaybe p)
(demaybe c)
(demaybe tvo)
(demaybe ty)
(demaybe bndr)
(demaybe occ)
where
demaybe Nothing = bottom
demaybe (Just x) = x
bottom = panic "PprEnv.initPprEnv: unspecified printing function"
\end{code}
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