Files
mercury/compiler/prog_io_goal.m
Simon Taylor 5544aed7ff Change the list constructor from ./2' to [|]/2'. `./2' will
Estimated hours taken: 3
Branches: main

Change the list constructor from `./2' to `[|]/2'. `./2' will
eventually become the module qualification operator.

library/parser.m:
library/io.m:
library/sparse_bitset.m:
library/std_util.m:
library/term_io.m:
compiler/mercury_to_mercury.m:
compiler/prog_io_dcg.m:
compiler/prog_io_goal.m:
compiler/prog_io_pragma.m:
compiler/prog_io_typeclass.m:
compiler/prog_io_util.m:
browser/interactive_query.m:
extras/moose/grammar.m:
extras/moose/moose.m:
extras/morphine/source/generate_call_site_cov.m:
extras/xml/xml.encoding.m:
samples/muz/higher_order.m:
tests/debugger/declarative/app.m:
tests/dppd/transpose_impl.m:
tests/hard_coded/ground_dd.m:
tests/hard_coded/split_c_files.m:
	Change all references to `./2' to use `[|]/2' instead.

compiler/typecheck.m:
	Handle `./2' as a special case in `report_error_undef_cons'.

	Warn about module list not being imported if `[|]/2' is undefined.

compiler/llds_out.m:
util/mdemangle.c:
profiler/demangle.m:
	Add name conversions for `[|]' (f_cons) and `[]' (f_nil).

NEWS:
doc/reference_manual.texi:
w3/tutorial/lists-n-things.m4:
	Document the changes.

tests/debugger/{,declarative}/*.exp*:
	Update test case results. For some tests the output changed
	because they output lists in the non-pretty format. For others,
	the output changed because the alphabetical ordering of the
	constructors of type `list/1' changed, so the numbering of
	the switch branches in the goal paths changed.
2001-09-25 09:37:12 +00:00

425 lines
14 KiB
Mathematica

%-----------------------------------------------------------------------------%
% Copyright (C) 1996-2001 The 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: prog_io_goal.m.
% Main author: fjh.
%
% This module defines the predicates that parse goals.
:- module prog_io_goal.
:- interface.
:- import_module prog_data.
:- import_module list, term.
% Convert a single term into a goal.
%
:- pred parse_goal(term, prog_varset, goal, prog_varset).
:- mode parse_goal(in, in, out, out) is det.
% Convert a term, possibly starting with `some [Vars]', into
% a list of variables and a goal. (If the term doesn't start
% with `some [Vars]', we return an empty list of variables.)
%
:- pred parse_some_vars_goal(term, prog_varset, list(prog_var),
goal, prog_varset).
:- mode parse_some_vars_goal(in, in, out, out, out) is det.
% parse_lambda_expression/3 converts the first argument to a lambda/2
% expression into a list of arguments, a list of their corresponding
% modes, and a determinism.
% The syntax of a lambda expression is
% `lambda([Var1::Mode1, ..., VarN::ModeN] is Det, Goal)'
% but this predicate just parses the first argument, i.e. the
% `[Var1::Mode1, ..., VarN::ModeN] is Det'
% part.
%
:- pred parse_lambda_expression(term, list(prog_term),
list(mode), determinism).
:- mode parse_lambda_expression(in, out, out, out) is semidet.
% parse_pred_expression/3 converts the first argument to a :-/2
% higher-order pred expression into a list of variables, a list
% of their corresponding modes, and a determinism. This is just
% a variant on parse_lambda_expression with a different syntax:
% `(pred(Var1::Mode1, ..., VarN::ModeN) is Det :- Goal)'.
%
:- pred parse_pred_expression(term, lambda_eval_method, list(prog_term),
list(mode), determinism).
:- mode parse_pred_expression(in, out, out, out, out) is semidet.
% parse_dcg_pred_expression/3 converts the first argument to a -->/2
% higher-order dcg pred expression into a list of arguments, a list
% of their corresponding modes and the two dcg argument modes, and a
% determinism.
% This is a variant of the higher-order pred syntax:
% `(pred(Var1::Mode1, ..., VarN::ModeN, DCG0Mode, DCGMode)
% is Det --> Goal)'.
%
:- pred parse_dcg_pred_expression(term, lambda_eval_method, list(prog_term),
list(mode), determinism).
:- mode parse_dcg_pred_expression(in, out, out, out, out) is semidet.
% parse_func_expression/3 converts the first argument to a :-/2
% higher-order func expression into a list of arguments, a list
% of their corresponding modes, and a determinism. The syntax
% of a higher-order func expression is
% `(func(Var1::Mode1, ..., VarN::ModeN) = (VarN1::ModeN1) is Det
% :- Goal)'
% or
% `(func(Var1, ..., VarN) = (VarN1) is Det :- Goal)'
% where the modes are assumed to be `in' for the
% function arguments and `out' for the result
% or
% `(func(Var1, ..., VarN) = (VarN1) :- Goal)'
% where the modes are assumed as above, and the
% determinism is assumed to be det
% or
% `(func(Var1, ..., VarN) = (VarN1). '
%
:- pred parse_func_expression(term, lambda_eval_method, list(prog_term),
list(mode), determinism).
:- mode parse_func_expression(in, out, out, out, out) is semidet.
% parse_lambda_eval_method/3 extracts the `aditi' or `aditi_top_down'
% annotation (if any) from a pred expression and returns the rest
% of the term.
:- pred parse_lambda_eval_method(term(T), lambda_eval_method, term(T)).
:- mode parse_lambda_eval_method(in, out, out) is det.
%-----------------------------------------------------------------------------%
:- implementation.
:- import_module mode_util, purity, prog_io, prog_io_util, term_util.
:- import_module term.
:- import_module int, map, string, std_util.
% Parse a goal.
%
% We could do some error-checking here, but all errors are picked up
% in either the type-checker or parser anyway.
parse_goal(Term, VarSet0, Goal, VarSet) :-
% first, get the goal context
(
Term = term__functor(_, _, Context)
;
Term = term__variable(_),
term__context_init(Context)
),
% We just check if it matches the appropriate pattern
% for one of the builtins. If it doesn't match any of the
% builtins, then it's just a predicate call.
(
% check for builtins...
Term = term__functor(term__atom(Name), Args, Context),
parse_goal_2(Name, Args, VarSet0, GoalExpr, VarSet1)
->
Goal = GoalExpr - Context,
VarSet = VarSet1
;
% it's not a builtin
term__coerce(Term, ArgsTerm),
(
% check for predicate calls
sym_name_and_args(ArgsTerm, SymName, Args)
->
VarSet = VarSet0,
Goal = call(SymName, Args, pure) - Context
;
% A call to a free variable, or to a number or string.
% Just translate it into a call to call/1 - the typechecker
% will catch calls to numbers and strings.
Goal = call(unqualified("call"), [ArgsTerm], pure)
- Context,
VarSet = VarSet0
)
).
%-----------------------------------------------------------------------------%
:- pred parse_goal_2(string, list(term), prog_varset, goal_expr, prog_varset).
:- mode parse_goal_2(in, in, in, out, out) is semidet.
parse_goal_2("true", [], V, true, V).
parse_goal_2("fail", [], V, fail, V).
parse_goal_2("=", [A0, B0], V, unify(A, B, pure), V) :-
term__coerce(A0, A),
term__coerce(B0, B).
/******
Since (A -> B) has different semantics in standard Prolog
(A -> B ; fail) than it does in NU-Prolog or Mercury (A -> B ; true),
for the moment we'll just disallow it.
parse_goal_2("->", [A0, B0], V0, if_then(Vars, A, B), V) :-
parse_some_vars_goal(A0, V0, Vars, A, V1),
parse_goal(B0, V1, B, V).
******/
parse_goal_2(",", [A0, B0], V0, (A, B), V) :-
parse_goal(A0, V0, A, V1),
parse_goal(B0, V1, B, V).
parse_goal_2("&", [A0, B0], V0, (A & B), V) :-
parse_goal(A0, V0, A, V1),
parse_goal(B0, V1, B, V).
parse_goal_2(";", [A0, B0], V0, R, V) :-
(
A0 = term__functor(term__atom("->"), [X0, Y0], _Context)
->
parse_some_vars_goal(X0, V0, Vars, X, V1),
parse_goal(Y0, V1, Y, V2),
parse_goal(B0, V2, B, V),
R = if_then_else(Vars, X, Y, B)
;
parse_goal(A0, V0, A, V1),
parse_goal(B0, V1, B, V),
R = (A;B)
).
/****
For consistency we also disallow if-then
parse_goal_2("if",
[term__functor(term__atom("then"), [A0, B0], _)], V0,
if_then(Vars, A, B), V) :-
parse_some_vars_goal(A0, V0, Vars, A, V1),
parse_goal(B0, V1, B, V).
****/
parse_goal_2("else", [
term__functor(term__atom("if"), [
term__functor(term__atom("then"), [A0, B0], _)
], _),
C0
], V0,
if_then_else(Vars, A, B, C), V) :-
parse_some_vars_goal(A0, V0, Vars, A, V1),
parse_goal(B0, V1, B, V2),
parse_goal(C0, V2, C, V).
parse_goal_2("not", [A0], V0, not(A), V) :-
parse_goal(A0, V0, A, V).
parse_goal_2("\\+", [A0], V0, not(A), V) :-
parse_goal(A0, V0, A, V).
parse_goal_2("all", [Vars0, A0], V0, all(Vars, A), V):-
term__coerce(Vars0, Vars1),
term__vars(Vars1, Vars),
parse_goal(A0, V0, A, V).
% handle implication
parse_goal_2("<=", [A0, B0], V0, implies(B, A), V):-
parse_goal(A0, V0, A, V1),
parse_goal(B0, V1, B, V).
parse_goal_2("=>", [A0, B0], V0, implies(A, B), V):-
parse_goal(A0, V0, A, V1),
parse_goal(B0, V1, B, V).
% handle equivalence
parse_goal_2("<=>", [A0, B0], V0, equivalent(A, B), V):-
parse_goal(A0, V0, A, V1),
parse_goal(B0, V1, B, V).
parse_goal_2("some", [Vars0, A0], V0, some(Vars, A), V):-
parse_list_of_vars(Vars0, Vars1),
list__map(term__coerce_var, Vars1, Vars),
parse_goal(A0, V0, A, V).
% The following is a temporary hack to handle `is' in
% the parser - we ought to handle it in the code generation -
% but then `is/2' itself is a bit of a hack
%
parse_goal_2("is", [A0, B0], V, unify(A, B, pure), V) :-
term__coerce(A0, A),
term__coerce(B0, B).
parse_goal_2("impure", [A0], V0, A, V) :-
parse_goal_with_purity(A0, V0, (impure), A, V).
parse_goal_2("semipure", [A0], V0, A, V) :-
parse_goal_with_purity(A0, V0, (semipure), A, V).
:- pred parse_goal_with_purity(term, prog_varset, purity, goal_expr,
prog_varset).
:- mode parse_goal_with_purity(in, in, in, out, out) is det.
parse_goal_with_purity(A0, V0, Purity, A, V) :-
parse_goal(A0, V0, A1, V),
( A1 = call(Pred, Args, pure) - _ ->
A = call(Pred, Args, Purity)
; A1 = unify(ProgTerm1, ProgTerm2, pure) - _ ->
A = unify(ProgTerm1, ProgTerm2, Purity)
;
% Inappropriate placement of an impurity marker, so we treat
% it like a predicate call. typecheck.m prints out something
% descriptive for these errors.
purity_name(Purity, PurityString),
term__coerce(A0, A2),
A = call(unqualified(PurityString), [A2], pure)
).
%-----------------------------------------------------------------------------%
parse_some_vars_goal(A0, VarSet0, Vars, A, VarSet) :-
(
A0 = term__functor(term__atom("some"), [Vars0, A1], _Context),
parse_list_of_vars(Vars0, Vars1)
->
list__map(term__coerce_var, Vars1, Vars),
parse_goal(A1, VarSet0, A, VarSet)
;
Vars = [],
parse_goal(A0, VarSet0, A, VarSet)
).
%-----------------------------------------------------------------------------%
parse_lambda_expression(LambdaExpressionTerm, Args, Modes, Det) :-
LambdaExpressionTerm = term__functor(term__atom("is"),
[LambdaArgsTerm, DetTerm], _),
DetTerm = term__functor(term__atom(DetString), [], _),
standard_det(DetString, Det),
parse_lambda_args(LambdaArgsTerm, Args, Modes).
:- pred parse_lambda_args(term, list(prog_term), list(mode)).
:- mode parse_lambda_args(in, out, out) is semidet.
parse_lambda_args(Term, Args, Modes) :-
( Term = term__functor(term__atom("[|]"), [Head, Tail], _Context) ->
parse_lambda_arg(Head, Arg, Mode),
Args = [Arg | Args1],
Modes = [Mode | Modes1],
parse_lambda_args(Tail, Args1, Modes1)
; Term = term__functor(term__atom("[]"), [], _) ->
Args = [],
Modes = []
;
Args = [Arg],
Modes = [Mode],
parse_lambda_arg(Term, Arg, Mode)
).
:- pred parse_lambda_arg(term, prog_term, mode).
:- mode parse_lambda_arg(in, out, out) is semidet.
parse_lambda_arg(Term, ArgTerm, Mode) :-
Term = term__functor(term__atom("::"), [ArgTerm0, ModeTerm], _),
term__coerce(ArgTerm0, ArgTerm),
convert_mode(ModeTerm, Mode).
%-----------------------------------------------------------------------------%
parse_pred_expression(PredTerm, EvalMethod, Args, Modes, Det) :-
PredTerm = term__functor(term__atom("is"),
[PredEvalArgsTerm, DetTerm], _),
DetTerm = term__functor(term__atom(DetString), [], _),
standard_det(DetString, Det),
parse_lambda_eval_method(PredEvalArgsTerm, EvalMethod, PredArgsTerm),
PredArgsTerm = term__functor(term__atom("pred"), PredArgsList, _),
parse_pred_expr_args(PredArgsList, Args, Modes).
parse_dcg_pred_expression(PredTerm, EvalMethod, Args, Modes, Det) :-
PredTerm = term__functor(term__atom("is"),
[PredEvalArgsTerm, DetTerm], _),
DetTerm = term__functor(term__atom(DetString), [], _),
standard_det(DetString, Det),
parse_lambda_eval_method(PredEvalArgsTerm, EvalMethod, PredArgsTerm),
PredArgsTerm = term__functor(term__atom("pred"), PredArgsList, _),
parse_dcg_pred_expr_args(PredArgsList, Args, Modes).
parse_func_expression(FuncTerm, EvalMethod, Args, Modes, Det) :-
%
% parse a func expression with specified modes and determinism
%
FuncTerm = term__functor(term__atom("is"), [EqTerm, DetTerm], _),
EqTerm = term__functor(term__atom("="),
[FuncEvalArgsTerm, RetTerm], _),
DetTerm = term__functor(term__atom(DetString), [], _),
standard_det(DetString, Det),
parse_lambda_eval_method(FuncEvalArgsTerm, EvalMethod, FuncArgsTerm),
FuncArgsTerm = term__functor(term__atom("func"), FuncArgsList, _),
( parse_pred_expr_args(FuncArgsList, Args0, Modes0) ->
parse_lambda_arg(RetTerm, RetArg, RetMode),
list__append(Args0, [RetArg], Args),
list__append(Modes0, [RetMode], Modes)
;
%
% the argument modes default to `in',
% the return mode defaults to `out'
%
in_mode(InMode),
out_mode(OutMode),
list__length(FuncArgsList, NumArgs),
list__duplicate(NumArgs, InMode, Modes0),
RetMode = OutMode,
list__append(Modes0, [RetMode], Modes),
list__append(FuncArgsList, [RetTerm], Args1),
list__map(term__coerce, Args1, Args)
).
parse_func_expression(FuncTerm, EvalMethod, Args, Modes, Det) :-
%
% parse a func expression with unspecified modes and determinism
%
FuncTerm = term__functor(term__atom("="),
[FuncEvalArgsTerm, RetTerm], _),
parse_lambda_eval_method(FuncEvalArgsTerm, EvalMethod, FuncArgsTerm),
FuncArgsTerm = term__functor(term__atom("func"), Args0, _),
%
% the argument modes default to `in',
% the return mode defaults to `out',
% and the determinism defaults to `det'.
%
in_mode(InMode),
out_mode(OutMode),
list__length(Args0, NumArgs),
list__duplicate(NumArgs, InMode, Modes0),
RetMode = OutMode,
Det = det,
list__append(Modes0, [RetMode], Modes),
list__append(Args0, [RetTerm], Args1),
list__map(term__coerce, Args1, Args).
parse_lambda_eval_method(Term0, EvalMethod, Term) :-
( Term0 = term__functor(term__atom(MethodStr), [Term1], _) ->
( MethodStr = "aditi_bottom_up" ->
EvalMethod = (aditi_bottom_up),
Term = Term1
; MethodStr = "aditi_top_down" ->
EvalMethod = (aditi_top_down),
Term = Term1
;
EvalMethod = normal,
Term = Term0
)
;
EvalMethod = normal,
Term = Term0
).
:- pred parse_pred_expr_args(list(term), list(prog_term), list(mode)).
:- mode parse_pred_expr_args(in, out, out) is semidet.
parse_pred_expr_args([], [], []).
parse_pred_expr_args([Term|Terms], [Arg|Args], [Mode|Modes]) :-
parse_lambda_arg(Term, Arg, Mode),
parse_pred_expr_args(Terms, Args, Modes).
% parse_dcg_pred_expr_args is like parse_pred_expr_args except
% that the last two elements of the list are the modes of the
% two dcg arguments.
:- pred parse_dcg_pred_expr_args(list(term), list(prog_term),
list(mode)).
:- mode parse_dcg_pred_expr_args(in, out, out) is semidet.
parse_dcg_pred_expr_args([DCGModeTerm0, DCGModeTerm1], [],
[DCGMode0, DCGMode1]) :-
convert_mode(DCGModeTerm0, DCGMode0),
convert_mode(DCGModeTerm1, DCGMode1).
parse_dcg_pred_expr_args([Term|Terms], [Arg|Args], [Mode|Modes]) :-
Terms = [_, _|_],
parse_lambda_arg(Term, Arg, Mode),
parse_dcg_pred_expr_args(Terms, Args, Modes).
%-----------------------------------------------------------------------------%