(* Title: Tools/Code/code_haskell.ML
Author: Florian Haftmann, TU Muenchen
Serializer for Haskell.
*)
signature CODE_HASKELL =
sig
val language_params: string
val target: string
val print_numeral: string -> int -> string
end;
structure Code_Haskell : CODE_HASKELL =
struct
val target = "Haskell";
val language_extensions =
["EmptyDataDecls", "RankNTypes", "ScopedTypeVariables"];
val language_pragma =
"{-# LANGUAGE " ^ commas language_extensions ^ " #-}";
val language_params =
space_implode " " (map (prefix "-X") language_extensions);
open Basic_Code_Symbol;
open Basic_Code_Thingol;
open Code_Printer;
infixr 5 @@;
infixr 5 @|;
(** Haskell serializer **)
val print_haskell_string =
let
fun char c =
let
val _ = if Symbol.is_ascii c then ()
else error "non-ASCII byte in Haskell string literal";
val s = ML_Syntax.print_symbol_char c;
in if s = "'" then "\\'" else s end;
in quote o translate_string char end;
fun print_haskell_stmt class_syntax tyco_syntax const_syntax
reserved deresolve deriving_show =
let
val deresolve_const = deresolve o Constant;
val deresolve_tyco = deresolve o Type_Constructor;
val deresolve_class = deresolve o Type_Class;
fun class_name class = case class_syntax class
of NONE => deresolve_class class
| SOME class => class;
fun print_typcontext tyvars vs = case maps (fn (v, sort) => map (pair v) sort) vs
of [] => []
| constraints => enum "," "(" ")" (
map (fn (v, class) =>
str (class_name class ^ " " ^ lookup_var tyvars v)) constraints)
@@ str " => ";
fun print_typforall tyvars vs = case map fst vs
of [] => []
| vnames => str "forall " :: Pretty.breaks
(map (str o lookup_var tyvars) vnames) @ str "." @@ Pretty.brk 1;
fun print_tyco_expr tyvars fxy (tyco, tys) =
brackify fxy (str tyco :: map (print_typ tyvars BR) tys)
and print_typ tyvars fxy (tyco `%% tys) = (case tyco_syntax tyco
of NONE => print_tyco_expr tyvars fxy (deresolve_tyco tyco, tys)
| SOME (_, print) => print (print_typ tyvars) fxy tys)
| print_typ tyvars fxy (ITyVar v) = (str o lookup_var tyvars) v;
fun print_typdecl tyvars (tyco, vs) =
print_tyco_expr tyvars NOBR (tyco, map ITyVar vs);
fun print_typscheme tyvars (vs, ty) =
Pretty.block (print_typforall tyvars vs @ print_typcontext tyvars vs @| print_typ tyvars NOBR ty);
fun print_term tyvars some_thm vars fxy (IConst const) =
print_app tyvars some_thm vars fxy (const, [])
| print_term tyvars some_thm vars fxy (t as (t1 `$ t2)) =
(case Code_Thingol.unfold_const_app t
of SOME app => print_app tyvars some_thm vars fxy app
| _ =>
brackify fxy [
print_term tyvars some_thm vars NOBR t1,
print_term tyvars some_thm vars BR t2
])
| print_term tyvars some_thm vars fxy (IVar NONE) =
str "_"
| print_term tyvars some_thm vars fxy (IVar (SOME v)) =
(str o lookup_var vars) v
| print_term tyvars some_thm vars fxy (t as _ `|=> _) =
let
val (binds, t') = Code_Thingol.unfold_pat_abs t;
val (ps, vars') = fold_map (print_bind tyvars some_thm BR o fst) binds vars;
in brackets (str "\\" :: ps @ str "->" @@ print_term tyvars some_thm vars' NOBR t') end
| print_term tyvars some_thm vars fxy (ICase case_expr) =
(case Code_Thingol.unfold_const_app (#primitive case_expr)
of SOME (app as ({ sym = Constant const, ... }, _)) =>
if is_none (const_syntax const)
then print_case tyvars some_thm vars fxy case_expr
else print_app tyvars some_thm vars fxy app
| NONE => print_case tyvars some_thm vars fxy case_expr)
and print_app_expr tyvars some_thm vars ({ sym, annotation, ... }, ts) =
let
val printed_const =
case annotation of
SOME ty => brackets [(str o deresolve) sym, str "::", print_typ tyvars NOBR ty]
| NONE => (str o deresolve) sym
in
printed_const :: map (print_term tyvars some_thm vars BR) ts
end
and print_app tyvars = gen_print_app (print_app_expr tyvars) (print_term tyvars) const_syntax
and print_bind tyvars some_thm fxy p = gen_print_bind (print_term tyvars) some_thm fxy p
and print_case tyvars some_thm vars fxy { clauses = [], ... } =
(brackify fxy o Pretty.breaks o map str) ["error", "\"empty case\""]
| print_case tyvars some_thm vars fxy (case_expr as { clauses = [(IVar _, _)], ... }) =
let
val (vs, body) = Code_Thingol.unfold_let_no_pat (ICase case_expr);
fun print_assignment ((some_v, _), t) vars =
vars
|> print_bind tyvars some_thm BR (IVar some_v)
|>> (fn p => semicolon [p, str "=", print_term tyvars some_thm vars NOBR t])
val (ps, vars') = fold_map print_assignment vs vars;
in brackify_block fxy (str "let {")
ps
(concat [str "}", str "in", print_term tyvars some_thm vars' NOBR body])
end
| print_case tyvars some_thm vars fxy { term = t, typ = ty, clauses = clauses as _ :: _, ... } =
let
fun print_select (pat, body) =
let
val (p, vars') = print_bind tyvars some_thm NOBR pat vars;
in semicolon [p, str "->", print_term tyvars some_thm vars' NOBR body] end;
in Pretty.block_enclose
(concat [str "(case", print_term tyvars some_thm vars NOBR t, str "of", str "{"], str "})")
(map print_select clauses)
end;
fun print_stmt (Constant const, Code_Thingol.Fun (((vs, ty), raw_eqs), _)) =
let
val tyvars = intro_vars (map fst vs) reserved;
fun print_err n =
(semicolon o map str) (
deresolve_const const
:: replicate n "_"
@ "="
:: "error"
@@ print_haskell_string const
);
fun print_eqn ((ts, t), (some_thm, _)) =
let
val vars = reserved
|> intro_base_names_for (is_none o const_syntax)
deresolve (t :: ts)
|> intro_vars ((fold o Code_Thingol.fold_varnames)
(insert (op =)) ts []);
in
semicolon (
(str o deresolve_const) const
:: map (print_term tyvars some_thm vars BR) ts
@ str "="
@@ print_term tyvars some_thm vars NOBR t
)
end;
in
Pretty.chunks (
semicolon [
(str o suffix " ::" o deresolve_const) const,
print_typscheme tyvars (vs, ty)
]
:: (case filter (snd o snd) raw_eqs
of [] => [print_err ((length o fst o Code_Thingol.unfold_fun) ty)]
| eqs => map print_eqn eqs)
)
end
| print_stmt (Type_Constructor tyco, Code_Thingol.Datatype (vs, [])) =
let
val tyvars = intro_vars vs reserved;
in
semicolon [
str "data",
print_typdecl tyvars (deresolve_tyco tyco, vs)
]
end
| print_stmt (Type_Constructor tyco, Code_Thingol.Datatype (vs, [((co, _), [ty])])) =
let
val tyvars = intro_vars vs reserved;
in
semicolon (
str "newtype"
:: print_typdecl tyvars (deresolve_tyco tyco, vs)
:: str "="
:: (str o deresolve_const) co
:: print_typ tyvars BR ty
:: (if deriving_show tyco then [str "deriving (Prelude.Read, Prelude.Show)"] else [])
)
end
| print_stmt (Type_Constructor tyco, Code_Thingol.Datatype (vs, co :: cos)) =
let
val tyvars = intro_vars vs reserved;
fun print_co ((co, _), tys) =
concat (
(str o deresolve_const) co
:: map (print_typ tyvars BR) tys
)
in
semicolon (
str "data"
:: print_typdecl tyvars (deresolve_tyco tyco, vs)
:: str "="
:: print_co co
:: map ((fn p => Pretty.block [str "| ", p]) o print_co) cos
@ (if deriving_show tyco then [str "deriving (Prelude.Read, Prelude.Show)"] else [])
)
end
| print_stmt (Type_Class class, Code_Thingol.Class (v, (classrels, classparams))) =
let
val tyvars = intro_vars [v] reserved;
fun print_classparam (classparam, ty) =
semicolon [
(str o deresolve_const) classparam,
str "::",
print_typ tyvars NOBR ty
]
in
Pretty.block_enclose (
Pretty.block [
str "class ",
Pretty.block (print_typcontext tyvars [(v, map snd classrels)]),
str (deresolve_class class ^ " " ^ lookup_var tyvars v),
str " where {"
],
str "};"
) (map print_classparam classparams)
end
| print_stmt (_, Code_Thingol.Classinst { class, tyco, vs, inst_params, ... }) =
let
val tyvars = intro_vars (map fst vs) reserved;
fun print_classparam_instance ((classparam, (const, _)), (thm, _)) =
case const_syntax classparam of
NONE => semicolon [
(str o Long_Name.base_name o deresolve_const) classparam,
str "=",
print_app tyvars (SOME thm) reserved NOBR (const, [])
]
| SOME (_, Code_Printer.Plain_printer s) => semicolon [
(str o Long_Name.base_name) s,
str "=",
print_app tyvars (SOME thm) reserved NOBR (const, [])
]
| SOME (k, Code_Printer.Complex_printer _) =>
let
val { sym = Constant c, dom, ... } = const;
val (vs, rhs) = (apfst o map) fst
(Code_Thingol.unfold_abs (Code_Thingol.eta_expand k (const, [])));
val s = if (is_some o const_syntax) c
then NONE else (SOME o Long_Name.base_name o deresolve_const) c;
val vars = reserved
|> intro_vars (map_filter I (s :: vs));
val lhs = IConst { sym = Constant classparam, typargs = [],
dicts = [], dom = dom, annotation = NONE } `$$ map IVar vs;
(*dictionaries are not relevant at this late stage,
and these consts never need type annotations for disambiguation *)
in
semicolon [
print_term tyvars (SOME thm) vars NOBR lhs,
str "=",
print_term tyvars (SOME thm) vars NOBR rhs
]
end;
in
Pretty.block_enclose (
Pretty.block [
str "instance ",
Pretty.block (print_typcontext tyvars vs),
str (class_name class ^ " "),
print_typ tyvars BR (tyco `%% map (ITyVar o fst) vs),
str " where {"
],
str "};"
) (map print_classparam_instance inst_params)
end;
in print_stmt end;
fun haskell_program_of_program ctxt module_prefix module_name reserved identifiers =
let
fun namify_fun upper base (nsp_fun, nsp_typ) =
let
val (base', nsp_fun') = Name.variant (Name.enforce_case upper base) nsp_fun;
in (base', (nsp_fun', nsp_typ)) end;
fun namify_typ base (nsp_fun, nsp_typ) =
let
val (base', nsp_typ') = Name.variant (Name.enforce_case true base) nsp_typ;
in (base', (nsp_fun, nsp_typ')) end;
fun namify_stmt (Code_Thingol.Fun (_, SOME _)) = pair
| namify_stmt (Code_Thingol.Fun _) = namify_fun false
| namify_stmt (Code_Thingol.Datatype _) = namify_typ
| namify_stmt (Code_Thingol.Datatypecons _) = namify_fun true
| namify_stmt (Code_Thingol.Class _) = namify_typ
| namify_stmt (Code_Thingol.Classrel _) = pair
| namify_stmt (Code_Thingol.Classparam _) = namify_fun false
| namify_stmt (Code_Thingol.Classinst _) = pair;
fun select_stmt (Code_Thingol.Fun (_, SOME _)) = false
| select_stmt (Code_Thingol.Fun _) = true
| select_stmt (Code_Thingol.Datatype _) = true
| select_stmt (Code_Thingol.Datatypecons _) = false
| select_stmt (Code_Thingol.Class _) = true
| select_stmt (Code_Thingol.Classrel _) = false
| select_stmt (Code_Thingol.Classparam _) = false
| select_stmt (Code_Thingol.Classinst _) = true;
in
Code_Namespace.flat_program ctxt
{ module_prefix = module_prefix, module_name = module_name, reserved = reserved,
identifiers = identifiers, empty_nsp = (reserved, reserved), namify_stmt = namify_stmt,
modify_stmt = fn stmt => if select_stmt stmt then SOME stmt else NONE }
end;
val prelude_import_operators = [
"==", "/=", "<", "<=", ">=", ">", "+", "-", "*", "/", "**", ">>=", ">>", "=<<", "&&", "||", "^", "^^", ".", "$", "$!", "++", "!!"
];
val prelude_import_unqualified = [
"Eq",
"error",
"id",
"return",
"not",
"fst", "snd",
"map", "filter", "concat", "concatMap", "reverse", "zip", "null", "takeWhile", "dropWhile", "all", "any",
"Integer", "negate", "abs", "divMod",
"String"
];
val prelude_import_unqualified_constr = [
("Bool", ["True", "False"]),
("Maybe", ["Nothing", "Just"])
];
fun serialize_haskell module_prefix string_classes ctxt { module_name,
reserved_syms, identifiers, includes, class_syntax, tyco_syntax, const_syntax } exports program =
let
(* build program *)
val reserved = fold (insert (op =) o fst) includes reserved_syms;
val { deresolver, flat_program = haskell_program } = haskell_program_of_program
ctxt module_prefix module_name (Name.make_context reserved) identifiers exports program;
(* print statements *)
fun deriving_show tyco =
let
fun deriv _ "fun" = false
| deriv tycos tyco = member (op =) tycos tyco
orelse case try (Code_Symbol.Graph.get_node program) (Type_Constructor tyco)
of SOME (Code_Thingol.Datatype (_, cs)) => forall (deriv' (tyco :: tycos))
(maps snd cs)
| NONE => true
and deriv' tycos (tyco `%% tys) = deriv tycos tyco
andalso forall (deriv' tycos) tys
| deriv' _ (ITyVar _) = true
in deriv [] tyco end;
fun print_stmt deresolve = print_haskell_stmt
class_syntax tyco_syntax const_syntax (make_vars reserved)
deresolve (if string_classes then deriving_show else K false);
(* print modules *)
fun print_module_frame module_name exports ps =
(module_name, Pretty.chunks2 (
concat [str "module",
case exports of
SOME ps => Pretty.block [str module_name, enclose "(" ")" (commas ps)]
| NONE => str module_name,
str "where {"
]
:: ps
@| str "}"
));
fun print_qualified_import module_name =
semicolon [str "import qualified", str module_name];
val import_common_ps =
enclose "import Prelude (" ");" (commas (map str
(map (Library.enclose "(" ")") prelude_import_operators @ prelude_import_unqualified)
@ map (fn (tyco, constrs) => (enclose (tyco ^ "(") ")" o commas o map str) constrs) prelude_import_unqualified_constr))
:: print_qualified_import "Prelude"
:: map (print_qualified_import o fst) includes;
fun print_module module_name (gr, imports) =
let
val deresolve = deresolver module_name;
val deresolve_import = SOME o str o deresolve;
val deresolve_import_attached = SOME o str o suffix "(..)" o deresolve;
fun print_import (sym, (_, Code_Thingol.Fun _)) = deresolve_import sym
| print_import (sym, (Code_Namespace.Public, Code_Thingol.Datatype _)) = deresolve_import_attached sym
| print_import (sym, (Code_Namespace.Opaque, Code_Thingol.Datatype _)) = deresolve_import sym
| print_import (sym, (Code_Namespace.Public, Code_Thingol.Class _)) = deresolve_import_attached sym
| print_import (sym, (Code_Namespace.Opaque, Code_Thingol.Class _)) = deresolve_import sym
| print_import (sym, (_, Code_Thingol.Classinst _)) = NONE;
val import_ps = import_common_ps @ map (print_qualified_import o fst) imports;
fun print_stmt' sym = case Code_Symbol.Graph.get_node gr sym
of (_, NONE) => NONE
| (_, SOME (export, stmt)) =>
SOME (if Code_Namespace.not_private export then print_import (sym, (export, stmt)) else NONE, markup_stmt sym (print_stmt deresolve (sym, stmt)));
val (export_ps, body_ps) = (flat o rev o Code_Symbol.Graph.strong_conn) gr
|> map_filter print_stmt'
|> split_list
|> apfst (map_filter I);
in
print_module_frame module_name (SOME export_ps)
((if null import_ps then [] else [Pretty.chunks import_ps]) @ body_ps)
end;
(*serialization*)
fun write_module width (SOME destination) (module_name, content) =
let
val _ = File.check_dir destination;
val filepath = (Path.append destination o Path.ext "hs" o Path.explode o implode
o separate "/" o Long_Name.explode) module_name;
val _ = Isabelle_System.mkdirs (Path.dir filepath);
in
(File.write filepath o format [] width o Pretty.chunks2)
[str language_pragma, content]
end
| write_module width NONE (_, content) = writeln (format [] width content);
in
Code_Target.serialization
(fn width => fn destination => K () o map (write_module width destination))
(fn present => fn width => rpair (try (deresolver ""))
o (map o apsnd) (format present width))
(map (fn (module_name, content) => print_module_frame module_name NONE [content]) includes
@ map (fn module_name => print_module module_name (Graph.get_node haskell_program module_name))
((flat o rev o Graph.strong_conn) haskell_program))
end;
val serializer : Code_Target.serializer =
Code_Target.parse_args (Scan.optional (Args.$$$ "root" -- Args.colon |-- Args.name) ""
-- Scan.optional (Args.$$$ "string_classes" >> K true) false
>> (fn (module_prefix, string_classes) =>
serialize_haskell module_prefix string_classes));
fun print_numeral typ = Library.enclose "(" (" :: " ^ typ ^ ")") o signed_string_of_int;
val literals = Literals {
literal_string = print_haskell_string,
literal_numeral = print_numeral "Integer",
literal_list = enum "," "[" "]",
infix_cons = (5, ":")
};
(** optional monad syntax **)
fun pretty_haskell_monad c_bind =
let
fun dest_bind t1 t2 = case Code_Thingol.split_pat_abs t2
of SOME ((pat, ty), t') =>
SOME ((SOME ((pat, ty), true), t1), t')
| NONE => NONE;
fun dest_monad (IConst { sym = Constant c, ... } `$ t1 `$ t2) =
if c = c_bind then dest_bind t1 t2
else NONE
| dest_monad t = case Code_Thingol.split_let_no_pat t
of SOME (((some_v, ty), tbind), t') =>
SOME ((SOME ((IVar some_v, ty), false), tbind), t')
| NONE => NONE;
val implode_monad = Code_Thingol.unfoldr dest_monad;
fun print_monad print_bind print_term (NONE, t) vars =
(semicolon [print_term vars NOBR t], vars)
| print_monad print_bind print_term (SOME ((bind, _), true), t) vars = vars
|> print_bind NOBR bind
|>> (fn p => semicolon [p, str "<-", print_term vars NOBR t])
| print_monad print_bind print_term (SOME ((bind, _), false), t) vars = vars
|> print_bind NOBR bind
|>> (fn p => semicolon [str "let", str "{", p, str "=", print_term vars NOBR t, str "}"]);
fun pretty _ print_term thm vars fxy [(t1, _), (t2, _)] = case dest_bind t1 t2
of SOME (bind, t') => let
val (binds, t'') = implode_monad t'
val (ps, vars') = fold_map (print_monad (gen_print_bind (K print_term) thm) print_term)
(bind :: binds) vars;
in
brackify_block fxy (str "do { ")
(ps @| print_term vars' NOBR t'')
(str " }")
end
| NONE => brackify_infix (1, L) fxy
(print_term vars (INFX (1, L)) t1, str ">>=", print_term vars (INFX (1, X)) t2)
in (2, pretty) end;
fun add_monad target' raw_c_bind thy =
let
val c_bind = Code.read_const thy raw_c_bind;
in
if target = target' then
thy
|> Code_Target.set_printings (Constant (c_bind, [(target,
SOME (Code_Printer.complex_const_syntax (pretty_haskell_monad c_bind)))]))
else error "Only Haskell target allows for monad syntax"
end;
(** Isar setup **)
val _ = Theory.setup
(Code_Target.add_language
(target, {serializer = serializer, literals = literals,
check = { env_var = "ISABELLE_GHC", make_destination = I,
make_command = fn module_name =>
"\"$ISABELLE_GHC\" " ^ language_params ^ " -odir build -hidir build -stubdir build -e \"\" " ^
module_name ^ ".hs"},
evaluation_args = []})
#> Code_Target.set_printings (Type_Constructor ("fun",
[(target, SOME (2, fn print_typ => fn fxy => fn [ty1, ty2] =>
brackify_infix (1, R) fxy (
print_typ (INFX (1, X)) ty1,
str "->",
print_typ (INFX (1, R)) ty2
)))]))
#> fold (Code_Target.add_reserved target) [
"hiding", "deriving", "where", "case", "of", "infix", "infixl", "infixr",
"import", "default", "forall", "let", "in", "class", "qualified", "data",
"newtype", "instance", "if", "then", "else", "type", "as", "do", "module"
]
#> fold (Code_Target.add_reserved target) prelude_import_unqualified
#> fold (Code_Target.add_reserved target o fst) prelude_import_unqualified_constr
#> fold (fold (Code_Target.add_reserved target) o snd) prelude_import_unqualified_constr);
val _ =
Outer_Syntax.command @{command_keyword code_monad} "define code syntax for monads"
(Parse.term -- Parse.name >> (fn (raw_bind, target) =>
Toplevel.theory (add_monad target raw_bind)));
end; (*struct*)