Files
mercury/compiler/lambda.m
Fergus Henderson 6d7f4b9b30 Undo dylan's changes in the names of some library entities,
Estimated hours taken: 1.5

Undo dylan's changes in the names of some library entities,
by applying the following sed script

	s/term_atom/term__atom/g
	s/term_string/term__string/g
	s/term_integer/term__integer/g
	s/term_float/term__float/g
	s/term_context/term__context/g
	s/term_functor/term__functor/g
	s/term_variable/term__variable/g
	s/_term__/_term_/g
	s/std_util__bool_/bool__/g

to all the `.m' and `.pp' files in the compiler and library directories.
The reason for undoing these changes was to minimize incompatibilities
with 0.4 (and besides, the changes were not a really good idea in the first
place).

I also moved `bool' to a separate module.
The main reason for that change is to ensure that the `__' prefix is
only used when it genuinely represents a module qualifier.
(That's what dylan's changes were trying to acheive, but `term__'
does genuinely represent a module qualifier.)

compiler/*.m:
	Apply sed script above;
	where appropriate, add `bool' to the list of imported modules.
1996-02-03 17:30:14 +00:00

362 lines
13 KiB
Mathematica

%-----------------------------------------------------------------------------%
% Copyright (C) 1995 University of Melbourne.
% This file may only be copied under the terms of the GNU General
% Public License - see the file COPYING in the Mercury distribution.
%-----------------------------------------------------------------------------%
% file: lambda.m
% main author: fjh
% This module is a pass over the HLDS to deal with lambda expressions.
%
% Lambda expressions are converted into separate predicates, so for
% example we translate
%
% :- pred p(int::in) is det.
% p(X) :-
% V__1 = lambda([Y::out] is nondet, q(Y, X))),
% solutions(V__1, List),
% ...
% :- pred q(int::out, int::in) is nondet.
%
% into
%
% p(X) :-
% V__1 = '__LambdaGoal__1'(X)
% solutions(V__1, List),
% ...
%
% :- pred '__LambdaGoal__1'(int::in, int::out) is nondet.
% '__LambdaGoal__1'(X, Y) :- q(Y, X).
%-----------------------------------------------------------------------------%
:- module (lambda).
:- interface.
:- import_module hlds.
:- import_module list, set, map.
:- import_module varset, term.
:- import_module prog_io.
:- pred lambda__process_pred(pred_id, module_info, module_info).
:- mode lambda__process_pred(in, in, out) is det.
:- pred lambda__transform_lambda(list(var), list(mode), determinism,
set(var), hlds__goal, unification,
varset, map(var, type), tvarset, module_info,
unify_rhs, unification, module_info).
:- mode lambda__transform_lambda(in, in, in, in, in, in, in, in, in, in,
out, out, out) is det.
%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%
:- implementation.
:- import_module bool, string, std_util, require.
:- import_module make_hlds.
:- type lambda_info --->
lambda_info(
varset, % from the proc_info
map(var, type), % from the proc_info
tvarset, % from the proc_info
module_info
).
%-----------------------------------------------------------------------------%
% This whole section just traverses the module structure.
lambda__process_pred(PredId, ModuleInfo0, ModuleInfo) :-
module_info_pred_info(ModuleInfo0, PredId, PredInfo),
pred_info_procids(PredInfo, ProcIds),
lambda__process_procs(PredId, ProcIds, ModuleInfo0, ModuleInfo).
:- pred lambda__process_procs(pred_id, list(proc_id), module_info, module_info).
:- mode lambda__process_procs(in, in, in, out) is det.
lambda__process_procs(_PredId, [], ModuleInfo, ModuleInfo).
lambda__process_procs(PredId, [ProcId | ProcIds], ModuleInfo0, ModuleInfo) :-
lambda__process_proc(PredId, ProcId, ModuleInfo0, ModuleInfo1),
lambda__process_procs(PredId, ProcIds, ModuleInfo1, ModuleInfo).
:- pred lambda__process_proc(pred_id, proc_id, module_info, module_info).
:- mode lambda__process_proc(in, in, in, out) is det.
lambda__process_proc(PredId, ProcId, ModuleInfo0, ModuleInfo) :-
module_info_preds(ModuleInfo0, PredTable0),
map__lookup(PredTable0, PredId, PredInfo0),
pred_info_procedures(PredInfo0, ProcTable0),
map__lookup(ProcTable0, ProcId, ProcInfo0),
lambda__process_proc_2(ProcInfo0, PredInfo0, ModuleInfo0,
ProcInfo, PredInfo1, ModuleInfo1),
pred_info_procedures(PredInfo1, ProcTable1),
map__set(ProcTable1, ProcId, ProcInfo, ProcTable),
pred_info_set_procedures(PredInfo1, ProcTable, PredInfo),
module_info_preds(ModuleInfo1, PredTable1),
map__set(PredTable1, PredId, PredInfo, PredTable),
module_info_set_preds(ModuleInfo1, PredTable, ModuleInfo).
:- pred lambda__process_proc_2(proc_info, pred_info, module_info,
proc_info, pred_info, module_info).
:- mode lambda__process_proc_2(in, in, in, out, out, out) is det.
lambda__process_proc_2(ProcInfo0, PredInfo0, ModuleInfo0,
ProcInfo, PredInfo, ModuleInfo) :-
% grab the appropriate fields from the pred_info and proc_info
pred_info_typevarset(PredInfo0, TypeVarSet0),
proc_info_variables(ProcInfo0, VarSet0),
proc_info_vartypes(ProcInfo0, VarTypes0),
proc_info_goal(ProcInfo0, Goal0),
% process the goal
Info0 = lambda_info(VarSet0, VarTypes0, TypeVarSet0, ModuleInfo0),
lambda__process_goal(Goal0, Goal, Info0, Info),
Info = lambda_info(VarSet, VarTypes, TypeVarSet, ModuleInfo),
% set the new values of the fields in proc_info and pred_info
proc_info_set_goal(ProcInfo0, Goal, ProcInfo1),
proc_info_set_variables(ProcInfo1, VarSet, ProcInfo2),
proc_info_set_vartypes(ProcInfo2, VarTypes, ProcInfo),
pred_info_set_typevarset(PredInfo0, TypeVarSet, PredInfo).
:- pred lambda__process_goal(hlds__goal, hlds__goal,
lambda_info, lambda_info).
:- mode lambda__process_goal(in, out, in, out) is det.
lambda__process_goal(Goal0 - GoalInfo0, Goal) -->
lambda__process_goal_2(Goal0, GoalInfo0, Goal).
:- pred lambda__process_goal_2(hlds__goal_expr, hlds__goal_info,
hlds__goal, lambda_info, lambda_info).
:- mode lambda__process_goal_2(in, in, out, in, out) is det.
lambda__process_goal_2(unify(XVar, Y, Mode, Unification, Context), GoalInfo,
Unify - GoalInfo) -->
( { Y = lambda_goal(Vars, Modes, Det, LambdaGoal0) } ->
% for lambda expressions, we must convert the lambda expression
% into a new predicate
{ LambdaGoal0 = _ - GoalInfo0 },
{ goal_info_get_nonlocals(GoalInfo0, NonLocals0) },
lambda__process_lambda(Vars, Modes, Det, NonLocals0,
LambdaGoal0, Unification, Y1, Unification1),
{ Unify = unify(XVar, Y1, Mode, Unification1, Context) }
;
% ordinary unifications are left unchanged
{ Unify = unify(XVar, Y, Mode, Unification, Context) }
).
% the rest of the clauses just process goals recursively
lambda__process_goal_2(conj(Goals0), GoalInfo, conj(Goals) - GoalInfo) -->
lambda__process_goal_list(Goals0, Goals).
lambda__process_goal_2(disj(Goals0), GoalInfo, disj(Goals) - GoalInfo) -->
lambda__process_goal_list(Goals0, Goals).
lambda__process_goal_2(not(Goal0), GoalInfo, not(Goal) - GoalInfo) -->
lambda__process_goal(Goal0, Goal).
lambda__process_goal_2(switch(Var, CanFail, Cases0), GoalInfo,
switch(Var, CanFail, Cases) - GoalInfo) -->
lambda__process_cases(Cases0, Cases).
lambda__process_goal_2(some(Vars, Goal0), GoalInfo,
some(Vars, Goal) - GoalInfo) -->
lambda__process_goal(Goal0, Goal).
lambda__process_goal_2(if_then_else(Vars, A0, B0, C0), GoalInfo,
if_then_else(Vars, A, B, C) - GoalInfo) -->
lambda__process_goal(A0, A),
lambda__process_goal(B0, B),
lambda__process_goal(C0, C).
lambda__process_goal_2(call(A,B,C,D,E,F,G), GoalInfo,
call(A,B,C,D,E,F,G) - GoalInfo) -->
[].
lambda__process_goal_2(pragma_c_code(A,B,C,D,E), GoalInfo,
pragma_c_code(A,B,C,D,E) - GoalInfo) -->
[].
:- pred lambda__process_goal_list(list(hlds__goal), list(hlds__goal),
lambda_info, lambda_info).
:- mode lambda__process_goal_list(in, out, in, out) is det.
lambda__process_goal_list([], []) --> [].
lambda__process_goal_list([Goal0 | Goals0], [Goal | Goals]) -->
lambda__process_goal(Goal0, Goal),
lambda__process_goal_list(Goals0, Goals).
:- pred lambda__process_cases(list(case), list(case),
lambda_info, lambda_info).
:- mode lambda__process_cases(in, out, in, out) is det.
lambda__process_cases([], []) --> [].
lambda__process_cases([case(ConsId, Goal0) | Cases0],
[case(ConsId, Goal) | Cases]) -->
lambda__process_goal(Goal0, Goal),
lambda__process_cases(Cases0, Cases).
:- pred lambda__process_lambda(list(var), list(mode), determinism,
set(var), hlds__goal, unification, unify_rhs, unification,
lambda_info, lambda_info).
:- mode lambda__process_lambda(in, in, in, in, in, in, out, out,
in, out) is det.
lambda__process_lambda(Vars, Modes, Det, OrigNonLocals0, LambdaGoal,
Unification0, Functor, Unification, LambdaInfo0, LambdaInfo) :-
LambdaInfo0 = lambda_info(VarSet, VarTypes, TVarSet, ModuleInfo0),
lambda__transform_lambda(Vars, Modes, Det, OrigNonLocals0, LambdaGoal,
Unification0, VarSet, VarTypes, TVarSet, ModuleInfo0,
Functor, Unification, ModuleInfo),
LambdaInfo = lambda_info(VarSet, VarTypes, TVarSet, ModuleInfo).
lambda__transform_lambda(Vars, Modes, Det, OrigNonLocals0, LambdaGoal,
Unification0, VarSet, VarTypes, TVarSet, ModuleInfo0,
Functor, Unification, ModuleInfo) :-
(
Unification0 = construct(Var0, _, _, UniModes0)
->
Var = Var0,
UniModes = UniModes0
;
error("polymorphism__transform_lambda: wierd unification")
),
%
% Optimize a special case: replace
% `lambda([Y1, Y2, ...] is Det, p(X1, X2, ..., Y1, Y2, ...))'
% where `p' has determinism `Det' with
% `p(X1, X2, ...)'
%
% XXX This optimization is only valid if the modes of the Xi are
% input, since only input arguments can be curried.
% Until this check is added, this optimization is incorrect,
% so I have disabled it - fjh.
LambdaGoal = _ - LambdaGoalInfo,
goal_info_get_nonlocals(LambdaGoalInfo, NonLocals0),
set__delete_list(NonLocals0, Vars, NonLocals),
set__to_sorted_list(NonLocals, ArgVars1),
(
/****************
XXX this optimization temporarily disabled, see comment above
LambdaGoal = call(PredId0, ModeId0, CallVars, _, _, PredName, _)
- _,
list__remove_suffix(CallVars, Vars, InitialVars),
module_info_pred_proc_info(ModuleInfo0, PredId0, ModeId0, _,
Call_ProcInfo),
proc_info_interface_code_model(Call_ProcInfo, Call_CodeModel),
determinism_to_code_model(Det, CodeModel),
% Check that the code models are compatible.
% Note that det is not compatible with semidet,
% and semidet is not compatible with nondet,
% since the arguments go in different registers.
% But det is compatible with nondet.
( CodeModel = Call_CodeModel
; CodeModel = model_non, Call_CodeModel = model_det
)
->
ArgVars = InitialVars,
PredId = PredId0,
ModeId = ModeId0,
unqualify_name(PredName, PName),
ModuleInfo = ModuleInfo0
;
****************/
% Prepare to create a new predicate for the lambda
% expression: work out the arguments, module name, predicate
% name, arity, arg types, determinism,
% context, status, etc. for the new predicate
ArgVars = ArgVars1,
list__append(ArgVars, Vars, AllArgVars),
module_info_name(ModuleInfo0, ModuleName),
module_info_next_lambda_count(ModuleInfo0, LambdaCount,
ModuleInfo1),
string__int_to_string(LambdaCount, LambdaCountStr),
string__append("__LambdaGoal__", LambdaCountStr, PName0),
string__append(ModuleName, PName0, PName),
PredName = unqualified(PName),
list__length(AllArgVars, Arity),
map__apply_to_list(AllArgVars, VarTypes, ArgTypes),
Cond = true,
goal_info_context(LambdaGoalInfo, LambdaContext),
Status = local,
MaybeDet = yes(Det),
% the TVarSet is a superset of what it really ought be,
% but that shouldn't matter
lambda__uni_modes_to_modes(UniModes, OrigArgModes),
% We have to jump through hoops to work out the mode
% of the lambda predicate. For introduced
% type_info arguments, we use the mode "in". For the original
% non-local vars, we use the modes from `UniModes'.
% For the lambda var arguments at the end,
% we use the mode in the lambda expression.
list__length(ArgVars, NumArgVars),
In = user_defined_mode(unqualified("in"), []),
list__duplicate(NumArgVars, In, InModes),
map__from_corresponding_lists(ArgVars, InModes,
ArgModesMap),
set__delete_list(OrigNonLocals0, Vars, OrigNonLocals),
set__to_sorted_list(OrigNonLocals, OrigArgVars),
map__from_corresponding_lists(OrigArgVars, OrigArgModes,
OrigArgModesMap),
map__overlay(ArgModesMap, OrigArgModesMap, ArgModesMap1),
map__values(ArgModesMap1, ArgModes1),
list__append(ArgModes1, Modes, AllArgModes),
%
% Now construct the pred_info for the new predicate, using
% the information computed above
%
clauses_info_init(Arity, ClausesInfo),
pred_info_init(ModuleName, PredName, Arity, TVarSet,
ArgTypes, Cond, LambdaContext, ClausesInfo, Status,
no, none, PredInfo0),
%
% Create a single mode for the new predicate, and insert
% the lambda goal as the body of that procedure.
%
pred_info_procedures(PredInfo0, Procs0),
next_mode_id(Procs0, MaybeDet, ModeId),
proc_info_init(Arity, AllArgModes, MaybeDet, LambdaContext,
ProcInfo0),
proc_info_set_body(ProcInfo0, VarSet, VarTypes, AllArgVars,
LambdaGoal, ProcInfo),
map__set(Procs0, ModeId, ProcInfo, Procs),
pred_info_set_procedures(PredInfo0, Procs, PredInfo),
%
% save the new predicate in the predicate table
%
module_info_get_predicate_table(ModuleInfo1, PredicateTable0),
predicate_table_insert(PredicateTable0, PredInfo,
PredId, PredicateTable),
module_info_set_predicate_table(ModuleInfo1, PredicateTable,
ModuleInfo)
),
Functor = functor(term__atom(PName), ArgVars),
ConsId = pred_const(PredId, ModeId),
Unification = construct(Var, ConsId, ArgVars, UniModes).
:- pred lambda__uni_modes_to_modes(list(uni_mode), list(mode)).
:- mode lambda__uni_modes_to_modes(in, out) is det.
% This predicate works out the modes of the original non-local
% variables of a lambda expression based on the list of uni_mode
% in the unify_info for the lambda unification.
lambda__uni_modes_to_modes([], []).
lambda__uni_modes_to_modes([UniMode | UniModes], [Mode | Modes]) :-
UniMode = ((_Initial0 - Initial1) -> (_Final0 - _Final1)),
Mode = (Initial1 -> Initial1),
lambda__uni_modes_to_modes(UniModes, Modes).
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%