diff options
Diffstat (limited to 'lib/stdlib')
| -rw-r--r-- | lib/stdlib/src/erl_eval.erl | 46 |
1 files changed, 45 insertions, 1 deletions
diff --git a/lib/stdlib/src/erl_eval.erl b/lib/stdlib/src/erl_eval.erl index 0f6d48b9a3..31c0e60fe1 100644 --- a/lib/stdlib/src/erl_eval.erl +++ b/lib/stdlib/src/erl_eval.erl @@ -29,7 +29,7 @@ -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]). +-export([is_constant_expr/1, partial_eval/1, eval_str/1]). %% Is used by standalone Erlang (escript). %% Also used by shell.erl. @@ -1557,6 +1557,50 @@ ev_expr({cons,_,H,T}) -> [ev_expr(H) | ev_expr(T)]. %% true = erl_internal:guard_bif(F, length(As)), %% apply(erlang, F, [ev_expr(X) || X <- As]); +%% eval_str(InStr) -> {ok, OutStr} | {error, ErrStr'} +%% InStr must represent a body +%% Note: If InStr is a binary it has to be a Latin-1 string. +%% If you have a UTF-8 encoded binary you have to call +%% unicode:characters_to_list/1 before the call to eval_str(). + +-define(result(F,D), lists:flatten(io_lib:format(F, D))). + +-spec eval_str(string() | unicode:latin1_binary()) -> + {'ok', string()} | {'error', string()}. + +eval_str(Str) when is_list(Str) -> + case erl_scan:tokens([], Str, 0) of + {more, _} -> + {error, "Incomplete form (missing .<cr>)??"}; + {done, {ok, Toks, _}, Rest} -> + case all_white(Rest) of + true -> + case erl_parse:parse_exprs(Toks) of + {ok, Exprs} -> + case catch erl_eval:exprs(Exprs, erl_eval:new_bindings()) of + {value, Val, _} -> + {ok, Val}; + Other -> + {error, ?result("*** eval: ~p", [Other])} + end; + {error, {_Line, Mod, Args}} -> + Msg = ?result("*** ~ts",[Mod:format_error(Args)]), + {error, Msg} + end; + false -> + {error, ?result("Non-white space found after " + "end-of-form :~ts", [Rest])} + end + end; +eval_str(Bin) when is_binary(Bin) -> + eval_str(binary_to_list(Bin)). + +all_white([$\s|T]) -> all_white(T); +all_white([$\n|T]) -> all_white(T); +all_white([$\t|T]) -> all_white(T); +all_white([]) -> true; +all_white(_) -> false. + ret_expr(_Old, New) -> %% io:format("~w: reduced ~s => ~s~n", %% [line(Old), erl_pp:expr(Old), erl_pp:expr(New)]), |