2 % (c) The University of Glasgow 2006
3 % (c) The AQUA Project, Glasgow University, 1996-1998
6 Printing of Core syntax
10 pprCoreExpr, pprParendExpr,
11 pprCoreBinding, pprCoreBindings, pprCoreAlt,
15 #include "HsVersions.h"
38 %************************************************************************
40 \subsection{Public interfaces for Core printing (excluding instances)}
42 %************************************************************************
44 @pprParendCoreExpr@ puts parens around non-atomic Core expressions.
47 pprCoreBindings :: OutputableBndr b => [Bind b] -> SDoc
48 pprCoreBinding :: OutputableBndr b => Bind b -> SDoc
49 pprCoreExpr :: OutputableBndr b => Expr b -> SDoc
50 pprParendExpr :: OutputableBndr b => Expr b -> SDoc
52 pprCoreBindings = pprTopBinds
53 pprCoreBinding = pprTopBind
55 instance OutputableBndr b => Outputable (Bind b) where
56 ppr bind = ppr_bind bind
58 instance OutputableBndr b => Outputable (Expr b) where
59 ppr expr = pprCoreExpr expr
63 %************************************************************************
67 %************************************************************************
70 pprTopBinds binds = vcat (map pprTopBind binds)
72 pprTopBind (NonRec binder expr)
73 = ppr_binding (binder,expr) $$ text ""
75 pprTopBind (Rec binds)
76 = vcat [ptext SLIT("Rec {"),
77 vcat (map ppr_binding binds),
78 ptext SLIT("end Rec }"),
83 ppr_bind :: OutputableBndr b => Bind b -> SDoc
85 ppr_bind (NonRec val_bdr expr) = ppr_binding (val_bdr, expr)
86 ppr_bind (Rec binds) = vcat (map pp binds)
88 pp bind = ppr_binding bind <> semi
90 ppr_binding :: OutputableBndr b => (b, Expr b) -> SDoc
91 ppr_binding (val_bdr, expr)
92 = pprBndr LetBind val_bdr $$
93 hang (ppr val_bdr <+> equals) 2 (pprCoreExpr expr)
97 pprParendExpr expr = ppr_expr parens expr
98 pprCoreExpr expr = ppr_expr noParens expr
100 noParens :: SDoc -> SDoc
105 ppr_expr :: OutputableBndr b => (SDoc -> SDoc) -> Expr b -> SDoc
106 -- The function adds parens in context that need
107 -- an atomic value (e.g. function args)
109 ppr_expr add_par (Type ty) = add_par (ptext SLIT("TYPE") <+> ppr ty) -- Wierd
111 ppr_expr add_par (Var name) = ppr name
112 ppr_expr add_par (Lit lit) = ppr lit
114 ppr_expr add_par (Cast expr co)
116 sep [pprParendExpr expr,
117 ptext SLIT("`cast`") <+> parens (pprCo co)]
119 pprCo co = sep [ppr co, dcolon <+> ppr (coercionKindPredTy co)]
122 ppr_expr add_par expr@(Lam _ _)
124 (bndrs, body) = collectBinders expr
127 hang (ptext SLIT("\\") <+> sep (map (pprBndr LambdaBind) bndrs) <+> arrow)
130 ppr_expr add_par expr@(App fun arg)
131 = case collectArgs expr of { (fun, args) ->
133 pp_args = sep (map pprArg args)
134 val_args = dropWhile isTypeArg args -- Drop the type arguments for tuples
135 pp_tup_args = sep (punctuate comma (map pprCoreExpr val_args))
138 Var f -> case isDataConWorkId_maybe f of
139 -- Notice that we print the *worker*
140 -- for tuples in paren'd format.
141 Just dc | saturated && isTupleTyCon tc
142 -> tupleParens (tupleTyConBoxity tc) pp_tup_args
145 saturated = val_args `lengthIs` idArity f
147 other -> add_par (hang (ppr f) 2 pp_args)
149 other -> add_par (hang (pprParendExpr fun) 2 pp_args)
152 ppr_expr add_par (Case expr var ty [(con,args,rhs)])
154 sep [sep [ptext SLIT("case") <+> pprCoreExpr expr,
155 ifPprDebug (braces (ppr ty)),
156 sep [ptext SLIT("of") <+> ppr_bndr var,
157 char '{' <+> ppr_case_pat con args]
163 ppr_bndr = pprBndr CaseBind
165 ppr_expr add_par (Case expr var ty alts)
167 sep [sep [ptext SLIT("case")
169 <+> ifPprDebug (braces (ppr ty)),
170 ptext SLIT("of") <+> ppr_bndr var <+> char '{'],
171 nest 2 (sep (punctuate semi (map pprCoreAlt alts))),
175 ppr_bndr = pprBndr CaseBind
178 -- special cases: let ... in let ...
179 -- ("disgusting" SLPJ)
182 ppr_expr add_par (Let bind@(NonRec val_bdr rhs@(Let _ _)) body)
185 hsep [ptext SLIT("let {"), (pprBndr LetBind val_bdr $$ ppr val_bndr), equals],
186 nest 2 (pprCoreExpr rhs),
191 ppr_expr add_par (Let bind@(NonRec val_bdr rhs) expr@(Let _ _))
193 (hang (ptext SLIT("let {"))
194 2 (hsep [ppr_binding (val_bdr,rhs),
199 -- general case (recursive case, too)
200 ppr_expr add_par (Let bind expr)
202 sep [hang (ptext keyword) 2 (ppr_bind bind),
203 hang (ptext SLIT("} in ")) 2 (pprCoreExpr expr)]
205 keyword = case bind of
206 Rec _ -> SLIT("__letrec {")
207 NonRec _ _ -> SLIT("let {")
209 ppr_expr add_par (Note (SCC cc) expr)
210 = add_par (sep [pprCostCentreCore cc, pprCoreExpr expr])
212 ppr_expr add_par (Note InlineMe expr)
213 = add_par $ ptext SLIT("__inline_me") <+> pprParendExpr expr
215 ppr_expr add_par (Note (CoreNote s) expr)
217 sep [sep [ptext SLIT("__core_note"), pprHsString (mkFastString s)],
220 pprCoreAlt (con, args, rhs)
221 = hang (ppr_case_pat con args) 2 (pprCoreExpr rhs)
223 ppr_case_pat con@(DataAlt dc) args
225 = tupleParens (tupleTyConBoxity tc) (hsep (punctuate comma (map ppr_bndr args))) <+> arrow
227 ppr_bndr = pprBndr CaseBind
230 ppr_case_pat con args
231 = ppr con <+> sep (map ppr_bndr args) <+> arrow
233 ppr_bndr = pprBndr CaseBind
235 pprArg (Type ty) = ptext SLIT("@") <+> pprParendType ty
236 pprArg expr = pprParendExpr expr
239 Other printing bits-and-bobs used with the general @pprCoreBinding@
240 and @pprCoreExpr@ functions.
243 instance OutputableBndr Var where
244 pprBndr = pprCoreBinder
246 pprCoreBinder :: BindingSite -> Var -> SDoc
247 pprCoreBinder LetBind binder
248 = vcat [sig, pprIdDetails binder, pragmas]
250 sig = pprTypedBinder binder
251 pragmas = ppIdInfo binder (idInfo binder)
253 -- Lambda bound type variables are preceded by "@"
254 pprCoreBinder LambdaBind bndr = parens (pprTypedBinder bndr)
256 -- Case bound things don't get a signature or a herald, unless we have debug on
257 pprCoreBinder CaseBind bndr
258 = getPprStyle $ \ sty ->
259 if debugStyle sty then
260 parens (pprTypedBinder bndr)
262 pprUntypedBinder bndr
264 pprUntypedBinder binder
265 | isTyVar binder = ptext SLIT("@") <+> ppr binder -- NB: don't print kind
266 | otherwise = pprIdBndr binder
268 pprTypedBinder binder
269 | isTyVar binder = ptext SLIT("@") <+> pprTyVarBndr binder
270 | otherwise = pprIdBndr binder <+> dcolon <+> pprType (idType binder)
272 pprTyVarBndr :: TyVar -> SDoc
274 = getPprStyle $ \ sty ->
275 if debugStyle sty then
276 hsep [ppr tyvar, dcolon, pprParendKind kind]
277 -- See comments with ppDcolon in PprCore.lhs
281 kind = tyVarKind tyvar
283 -- pprIdBndr does *not* print the type
284 -- When printing any Id binder in debug mode, we print its inline pragma and one-shot-ness
285 pprIdBndr id = ppr id <+> pprIdBndrInfo (idInfo id)
288 = megaSeqIdInfo `seq` doc -- The seq is useful for poking on black holes
290 prag_info = inlinePragInfo info
291 occ_info = occInfo info
292 dmd_info = newDemandInfo info
293 lbv_info = lbvarInfo info
295 no_info = isAlwaysActive prag_info && isNoOcc occ_info &&
296 (case dmd_info of { Nothing -> True; Just d -> isTop d }) &&
297 hasNoLBVarInfo lbv_info
299 doc | no_info = empty
301 = brackets $ hsep [ppr prag_info, ppr occ_info,
302 ppr dmd_info, ppr lbv_info
303 #ifdef OLD_STRICTNESS
304 , ppr (demandInfo id)
311 pprIdDetails :: Id -> SDoc
312 pprIdDetails id | isGlobalId id = ppr (globalIdDetails id)
313 | isExportedId id = ptext SLIT("[Exported]")
316 ppIdInfo :: Id -> IdInfo -> SDoc
319 vcat [ ppArityInfo a,
320 ppWorkerInfo (workerInfo info),
321 ppCafInfo (cafInfo info),
322 #ifdef OLD_STRICTNESS
326 pprNewStrictness (newStrictnessInfo info),
327 if null rules then empty
328 else ptext SLIT("RULES:") <+> vcat (map pprRule rules)
329 -- Inline pragma, occ, demand, lbvar info
330 -- printed out with all binders (when debug is on);
331 -- see PprCore.pprIdBndr
335 #ifdef OLD_STRICTNESS
336 s = strictnessInfo info
339 rules = specInfoRules (specInfo info)
344 instance Outputable CoreRule where
347 pprRules :: [CoreRule] -> SDoc
348 pprRules rules = vcat (map pprRule rules)
350 pprRule :: CoreRule -> SDoc
351 pprRule (BuiltinRule { ru_fn = fn, ru_name = name})
352 = ptext SLIT("Built in rule for") <+> ppr fn <> colon <+> doubleQuotes (ftext name)
354 pprRule (Rule { ru_name = name, ru_act = act, ru_fn = fn,
355 ru_bndrs = tpl_vars, ru_args = tpl_args,
357 = hang (doubleQuotes (ftext name) <+> ppr act)
358 4 (sep [ptext SLIT("forall") <+> braces (sep (map pprTypedBinder tpl_vars)),
359 nest 2 (ppr fn <+> sep (map pprArg tpl_args)),
360 nest 2 (ptext SLIT("=") <+> pprCoreExpr rhs)