aboutsummaryrefslogtreecommitdiffstats
path: root/lib/stdlib/src/erl_eval.erl
diff options
context:
space:
mode:
Diffstat (limited to 'lib/stdlib/src/erl_eval.erl')
-rw-r--r--lib/stdlib/src/erl_eval.erl221
1 files changed, 220 insertions, 1 deletions
diff --git a/lib/stdlib/src/erl_eval.erl b/lib/stdlib/src/erl_eval.erl
index 4ee11383da..0f6d48b9a3 100644
--- a/lib/stdlib/src/erl_eval.erl
+++ b/lib/stdlib/src/erl_eval.erl
@@ -27,7 +27,8 @@
-export([exprs/2,exprs/3,exprs/4,expr/2,expr/3,expr/4,expr/5,
expr_list/2,expr_list/3,expr_list/4]).
-export([new_bindings/0,bindings/1,binding/2,add_binding/3,del_binding/2]).
-
+-export([extended_parse_exprs/1, extended_parse_term/1,
+ subst_values_for_vars/2]).
-export([is_constant_expr/1, partial_eval/1]).
%% Is used by standalone Erlang (escript).
@@ -1286,6 +1287,224 @@ merge_bindings(Bs1, Bs2) ->
%% error -> Bs
%% end
%% end, Bs2, Bs1).
+
+%% Substitute {value, A, Item} for {var, A, Var}, preserving A.
+%% {value, A, Item} is a shell/erl_eval convention, and for example
+%% the linter cannot handle it.
+
+-spec subst_values_for_vars(ExprList, Bindings) -> [term()] when
+ ExprList :: [erl_parse:abstract_expr()],
+ Bindings :: binding_struct().
+
+subst_values_for_vars({var, A, V}=Var, Bs) ->
+ case erl_eval:binding(V, Bs) of
+ {value, Value} ->
+ {value, A, Value};
+ unbound ->
+ Var
+ end;
+subst_values_for_vars(L, Bs) when is_list(L) ->
+ [subst_values_for_vars(E, Bs) || E <- L];
+subst_values_for_vars(T, Bs) when is_tuple(T) ->
+ list_to_tuple(subst_values_for_vars(tuple_to_list(T), Bs));
+subst_values_for_vars(T, _Bs) ->
+ T.
+
+%% `Tokens' is assumed to have been scanned with the 'text' option.
+%% The annotations of the returned expressions are locations.
+%%
+%% Can handle pids, ports, references, and external funs ("items").
+%% Known items are represented by variables in the erl_parse tree, and
+%% the items themselves are stored in the returned bindings.
+
+-spec extended_parse_exprs(Tokens) ->
+ {'ok', ExprList, Bindings} | {'error', ErrorInfo} when
+ Tokens :: [erl_scan:token()],
+ ExprList :: [erl_parse:abstract_expr()],
+ Bindings :: erl_eval:binding_struct(),
+ ErrorInfo :: erl_parse:error_info().
+
+extended_parse_exprs(Tokens) ->
+ Ts = tokens_fixup(Tokens),
+ case erl_parse:parse_exprs(Ts) of
+ {ok, Exprs0} ->
+ {Exprs, Bs} = expr_fixup(Exprs0),
+ {ok, reset_expr_anno(Exprs), Bs};
+ _ErrorInfo ->
+ erl_parse:parse_exprs(reset_token_anno(Ts))
+ end.
+
+tokens_fixup([]) -> [];
+tokens_fixup([T|Ts]=Ts0) ->
+ try token_fixup(Ts0) of
+ {NewT, NewTs} ->
+ [NewT|tokens_fixup(NewTs)]
+ catch
+ _:_ ->
+ [T|tokens_fixup(Ts)]
+ end.
+
+token_fixup(Ts) ->
+ {AnnoL, NewTs, FixupTag} = unscannable(Ts),
+ String = lists:append([erl_anno:text(A) || A <- AnnoL]),
+ _ = (fixup_fun(FixupTag))(String),
+ NewAnno = erl_anno:set_text(fixup_text(FixupTag), hd(AnnoL)),
+ {{string, NewAnno, String}, NewTs}.
+
+unscannable([{'#', A1}, {var, A2, 'Fun'}, {'<', A3}, {atom, A4, _},
+ {'.', A5}, {float, A6, _}, {'>', A7}|Ts]) ->
+ {[A1, A2, A3, A4, A5, A6, A7], Ts, function};
+unscannable([{'#', A1}, {var, A2, 'Fun'}, {'<', A3}, {atom, A4, _},
+ {'.', A5}, {atom, A6, _}, {'.', A7}, {integer, A8, _},
+ {'>', A9}|Ts]) ->
+ {[A1, A2, A3, A4, A5, A6, A7, A8, A9], Ts, function};
+unscannable([{'<', A1}, {float, A2, _}, {'.', A3}, {integer, A4, _},
+ {'>', A5}|Ts]) ->
+ {[A1, A2, A3, A4, A5], Ts, pid};
+unscannable([{'#', A1}, {var, A2, 'Port'}, {'<', A3}, {float, A4, _},
+ {'>', A5}|Ts]) ->
+ {[A1, A2, A3, A4, A5], Ts, port};
+unscannable([{'#', A1}, {var, A2, 'Ref'}, {'<', A3}, {float, A4, _},
+ {'.', A5}, {float, A6, _}, {'>', A7}|Ts]) ->
+ {[A1, A2, A3, A4, A5, A6, A7], Ts, reference}.
+
+expr_fixup(Expr0) ->
+ {Expr, Bs, _} = expr_fixup(Expr0, erl_eval:new_bindings(), 1),
+ {Expr, Bs}.
+
+expr_fixup({string,A,S}=T, Bs0, I) ->
+ try string_fixup(A, S) of
+ Value ->
+ Var = new_var(I),
+ Bs = erl_eval:add_binding(Var, Value, Bs0),
+ {{var, A, Var}, Bs, I+1}
+ catch
+ _:_ ->
+ {T, Bs0, I}
+ end;
+expr_fixup(Tuple, Bs0, I0) when is_tuple(Tuple) ->
+ {L, Bs, I} = expr_fixup(tuple_to_list(Tuple), Bs0, I0),
+ {list_to_tuple(L), Bs, I};
+expr_fixup([E0|Es0], Bs0, I0) ->
+ {E, Bs1, I1} = expr_fixup(E0, Bs0, I0),
+ {Es, Bs, I} = expr_fixup(Es0, Bs1, I1),
+ {[E|Es], Bs, I};
+expr_fixup(T, Bs, I) ->
+ {T, Bs, I}.
+
+string_fixup(A, S) ->
+ Text = erl_anno:text(A),
+ FixupTag = fixup_tag(Text, S),
+ (fixup_fun(FixupTag))(S).
+
+new_var(I) ->
+ list_to_atom(lists:concat(['__ExtendedParseExprs_', I, '__'])).
+
+reset_token_anno(Tokens) ->
+ [setelement(2, T, (reset_anno())(element(2, T))) || T <- Tokens].
+
+reset_expr_anno(Exprs) ->
+ [erl_parse:map_anno(reset_anno(), E) || E <- Exprs].
+
+reset_anno() ->
+ fun(A) -> erl_anno:new(erl_anno:location(A)) end.
+
+fixup_fun(function) -> fun function/1;
+fixup_fun(pid) -> fun erlang:list_to_pid/1;
+fixup_fun(port) -> fun erlang:list_to_port/1;
+fixup_fun(reference) -> fun erlang:list_to_ref/1.
+
+function(S) ->
+ %% External function.
+ {ok, [_, _, _,
+ {atom, _, Module}, _,
+ {atom, _, Function}, _,
+ {integer, _, Arity}|_], _} = erl_scan:string(S),
+ erlang:make_fun(Module, Function, Arity).
+
+fixup_text(function) -> "function";
+fixup_text(pid) -> "pid";
+fixup_text(port) -> "port";
+fixup_text(reference) -> "reference".
+
+fixup_tag("function", "#"++_) -> function;
+fixup_tag("pid", "<"++_) -> pid;
+fixup_tag("port", "#"++_) -> port;
+fixup_tag("reference", "#"++_) -> reference.
+
+%%% End of extended_parse_exprs.
+
+%% `Tokens' is assumed to have been scanned with the 'text' option.
+%%
+%% Can handle pids, ports, references, and external funs.
+
+-spec extended_parse_term(Tokens) ->
+ {'ok', Term} | {'error', ErrorInfo} when
+ Tokens :: [erl_scan:token()],
+ Term :: term(),
+ ErrorInfo :: erl_parse:error_info().
+
+extended_parse_term(Tokens) ->
+ case extended_parse_exprs(Tokens) of
+ {ok, [Expr], Bindings} ->
+ try normalise(Expr, Bindings) of
+ Term ->
+ {ok, Term}
+ catch
+ _:_ ->
+ Loc = erl_anno:location(element(2, Expr)),
+ {error,{Loc,?MODULE,"bad term"}}
+ end;
+ {ok, [_,Expr|_], _Bindings} ->
+ Loc = erl_anno:location(element(2, Expr)),
+ {error,{Loc,?MODULE,"bad term"}};
+ {error, _} = Error ->
+ Error
+ end.
+
+%% From erl_parse.
+normalise({var, _, V}, Bs) ->
+ {value, Value} = erl_eval:binding(V, Bs),
+ Value;
+normalise({char,_,C}, _Bs) -> C;
+normalise({integer,_,I}, _Bs) -> I;
+normalise({float,_,F}, _Bs) -> F;
+normalise({atom,_,A}, _Bs) -> A;
+normalise({string,_,S}, _Bs) -> S;
+normalise({nil,_}, _Bs) -> [];
+normalise({bin,_,Fs}, Bs) ->
+ {value, B, _} =
+ eval_bits:expr_grp(Fs, [],
+ fun(E, _) ->
+ {value, normalise(E, Bs), []}
+ end, [], true),
+ B;
+normalise({cons,_,Head,Tail}, Bs) ->
+ [normalise(Head, Bs)|normalise(Tail, Bs)];
+normalise({tuple,_,Args}, Bs) ->
+ list_to_tuple(normalise_list(Args, Bs));
+normalise({map,_,Pairs}, Bs) ->
+ maps:from_list(lists:map(fun
+ %% only allow '=>'
+ ({map_field_assoc,_,K,V}) ->
+ {normalise(K, Bs),normalise(V, Bs)}
+ end, Pairs));
+%% Special case for unary +/-.
+normalise({op,_,'+',{char,_,I}}, _Bs) -> I;
+normalise({op,_,'+',{integer,_,I}}, _Bs) -> I;
+normalise({op,_,'+',{float,_,F}}, _Bs) -> F;
+normalise({op,_,'-',{char,_,I}}, _Bs) -> -I; %Weird, but compatible!
+normalise({op,_,'-',{integer,_,I}}, _Bs) -> -I;
+normalise({op,_,'-',{float,_,F}}, _Bs) -> -F;
+normalise({'fun',_,{function,{atom,_,M},{atom,_,F},{integer,_,A}}}, _Bs) ->
+ %% Since "#Fun<M.F.A>" is recognized, "fun M:F/A" should be too.
+ fun M:F/A.
+
+normalise_list([H|T], Bs) ->
+ [normalise(H, Bs)|normalise_list(T, Bs)];
+normalise_list([], _Bs) ->
+ [].
+
%%----------------------------------------------------------------------------
%%
%% Evaluate expressions:
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 17:51:40 +0000