2 % (c) The University of Glasgow 2001-2006
6 module PprExternalCore () where
15 instance Show Module where
16 showsPrec _ m = shows (pmodule m)
18 instance Show Tdef where
19 showsPrec _ t = shows (ptdef t)
21 instance Show Cdef where
22 showsPrec _ c = shows (pcdef c)
24 instance Show Vdefg where
25 showsPrec _ v = shows (pvdefg v)
27 instance Show Exp where
28 showsPrec _ e = shows (pexp e)
30 instance Show Alt where
31 showsPrec _ a = shows (palt a)
33 instance Show Ty where
34 showsPrec _ t = shows (pty t)
36 instance Show Kind where
37 showsPrec _ k = shows (pkind k)
39 instance Show Lit where
40 showsPrec _ l = shows (plit l)
46 pmodule :: Module -> Doc
47 pmodule (Module mname tdefs vdefgs) =
48 (text "%module" <+> text mname)
49 $$ indent ((vcat (map ((<> char ';') . ptdef) tdefs))
50 $$ (vcat (map ((<> char ';') . pvdefg) vdefgs)))
53 ptdef (Data tcon tbinds cdefs) =
54 (text "%data" <+> pqname tcon <+> (hsep (map ptbind tbinds)) <+> char '=')
55 $$ indent (braces ((vcat (punctuate (char ';') (map pcdef cdefs)))))
57 ptdef (Newtype tcon tbinds (coercion,tbs,k) rep) =
58 -- Here we take apart the newtype tycon in order to get the newtype coercion,
59 -- which needs to be represented in the External Core file because it's not
60 -- straightforward to derive its definition from the newtype declaration alone.
61 -- At the same time, we need the newtype decl to declare the tycon itself.
63 text "%newtype" <+> pqname tcon <+> (hsep (map ptbind tbinds))
64 $$ indent (axiomclause $$ repclause)
65 where axiomclause = char '^'
66 <+> parens (pqname coercion <+> (hsep (map ptbind tbs))
69 repclause = case rep of
70 Just ty -> char '=' <+> pty ty
75 pcdef (Constr dcon tbinds tys) =
76 (pqname dcon) <+> (sep [hsep (map pattbind tbinds),sep (map paty tys)])
77 pcdef (GadtConstr dcon ty) =
78 (pqname dcon) <+> text "::" <+> pty ty
81 pname id = text (zEncodeString id)
83 pqname :: Qual Id -> Doc
84 pqname ("",id) = pname id
85 pqname (m,id) = text m <> char '.' <> pname id
87 ptbind, pattbind :: Tbind -> Doc
88 ptbind (t,Klifted) = pname t
89 ptbind (t,k) = parens (pname t <> text "::" <> pkind k)
91 pattbind (t,k) = char '@' <> ptbind (t,k)
93 pakind, pkind :: Kind -> Doc
94 pakind (Klifted) = char '*'
95 pakind (Kunlifted) = char '#'
96 pakind (Kopen) = char '?'
97 pakind k = parens (pkind k)
99 pkind (Karrow k1 k2) = parens (pakind k1 <> text "->" <> pkind k2)
100 pkind (Keq t1 t2) = parens (parens (pty t1) <+> text ":=:" <+>
104 paty, pbty, pty :: Ty -> Doc
105 paty (Tvar n) = pname n
106 paty (Tcon c) = pqname c
107 paty t = parens (pty t)
109 pbty (Tapp(Tapp(Tcon tc) t1) t2) | tc == tcArrow = parens(fsep [pbty t1, text "->",pty t2])
110 pbty (Tapp t1 t2) = pappty t1 [t2]
113 pty (Tapp(Tapp(Tcon tc) t1) t2) | tc == tcArrow = fsep [pbty t1, text "->",pty t2]
114 pty (Tforall tb t) = text "%forall" <+> pforall [tb] t
117 pappty :: Ty -> [Ty] -> Doc
118 pappty (Tapp t1 t2) ts = pappty t1 (t2:ts)
119 pappty t ts = sep (map paty (t:ts))
121 pforall :: [Tbind] -> Ty -> Doc
122 pforall tbs (Tforall tb t) = pforall (tbs ++ [tb]) t
123 pforall tbs t = hsep (map ptbind tbs) <+> char '.' <+> pty t
125 pvdefg :: Vdefg -> Doc
126 pvdefg (Rec vdefs) = text "%rec" $$ braces (indent (vcat (punctuate (char ';') (map pvdef vdefs))))
127 pvdefg (Nonrec vdef) = pvdef vdef
130 -- TODO: Think about whether %local annotations are actually needed.
131 -- Right now, the local flag is never used, because the Core doc doesn't
132 -- explain the meaning of %local.
133 pvdef (_l,v,t,e) = sep [(pqname v <+> text "::" <+> pty t <+> char '='),
136 paexp, pfexp, pexp :: Exp -> Doc
137 paexp (Var x) = pqname x
138 paexp (Dcon x) = pqname x
139 paexp (Lit l) = plit l
140 paexp e = parens(pexp e)
142 plamexp :: [Bind] -> Exp -> Doc
143 plamexp bs (Lam b e) = plamexp (bs ++ [b]) e
144 plamexp bs e = sep [sep (map pbind bs) <+> text "->",
148 pbind (Tb tb) = char '@' <+> ptbind tb
149 pbind (Vb vb) = pvbind vb
151 pfexp (App e1 e2) = pappexp e1 [Left e2]
152 pfexp (Appt e t) = pappexp e [Right t]
155 pappexp :: Exp -> [Either Exp Ty] -> Doc
156 pappexp (App e1 e2) as = pappexp e1 (Left e2:as)
157 pappexp (Appt e t) as = pappexp e (Right t:as)
158 pappexp e as = fsep (paexp e : map pa as)
159 where pa (Left e) = paexp e
160 pa (Right t) = char '@' <+> paty t
162 pexp (Lam b e) = char '\\' <+> plamexp [b] e
163 pexp (Let vd e) = (text "%let" <+> pvdefg vd) $$ (text "%in" <+> pexp e)
164 pexp (Case e vb ty alts) = sep [text "%case" <+> paty ty <+> paexp e,
165 text "%of" <+> pvbind vb]
166 $$ (indent (braces (vcat (punctuate (char ';') (map palt alts)))))
167 pexp (Cast e co) = (text "%cast" <+> parens (pexp e)) $$ paty co
168 pexp (Note s e) = (text "%note" <+> pstring s) $$ pexp e
169 pexp (External n cc t) = (text "%external" <+> text cc <+> pstring n) $$ paty t
170 pexp (DynExternal cc t) = (text "%dynexternal" <+> text cc) $$ paty t
171 pexp (Label n) = (text "%label" <+> pstring n)
174 pvbind :: Vbind -> Doc
175 pvbind (x,t) = parens(pname x <> text "::" <> pty t)
178 palt (Acon c tbs vbs e) =
180 sep (map pattbind tbs),
181 sep (map pvbind vbs) <+> text "->"]
184 (plit l <+> text "->")
191 plit (Lint i t) = parens (integer i <> text "::" <> pty t)
192 -- we use (text (show r)) because "(rational r)" was printing out things
193 -- like "2.0e-2" (which isn't External Core)
194 plit (Lrational r t) = parens (text (show r) <> text "::" <> pty t)
195 plit (Lchar c t) = parens (text ("\'" ++ escape [c] ++ "\'") <> text "::" <> pty t)
196 plit (Lstring s t) = parens (pstring s <> text "::" <> pty t)
198 pstring :: String -> Doc
199 pstring s = doubleQuotes(text (escape s))
201 escape :: String -> String
202 escape s = foldr f [] (map ord s)
205 | cv > 0xFF = '\\':'x':hs ++ rest
206 | (cv < 0x20 || cv > 0x7e || cv == 0x22 || cv == 0x27 || cv == 0x5c) =
208 where (q1,r1) = quotRem cv 16
211 hs = dropWhile (=='0') $ reverse $ mkHex cv
213 mkHex cv = intToDigit r : mkHex q
214 where (q,r) = quotRem cv 16
215 f cv rest = (chr cv):rest