static REBOOL Same_Func(const RELVAL *val, const RELVAL *arg)
{
assert(IS_FUNCTION(val) && IS_FUNCTION(arg));
if (VAL_FUNC_PARAMLIST(val) == VAL_FUNC_PARAMLIST(arg)) {
assert(VAL_FUNC_DISPATCHER(val) == VAL_FUNC_DISPATCHER(arg));
assert(VAL_FUNC_BODY(val) == VAL_FUNC_BODY(arg));
// All functions that have the same paramlist are not necessarily the
// "same function". For instance, every RETURN shares a common
// paramlist, but the binding is different in the REBVAL instances
// in order to know where to "exit from".
return LOGICAL(VAL_BINDING(val) == VAL_BINDING(arg));
}
return FALSE;
}
//
// Do_String()
//
// This is a version of a routine that was offered by the RL_Api, which has
// been expanded here in order to permit the necessary customizations for
// interesting REPL behavior w.r.t. binding, error handling, and response
// to throws.
//
// !!! Now that this code has been moved into the host, the convoluted
// integer-return-scheme can be eliminated and the code integrated more
// clearly into the surrounding calls.
//
int Do_String(
int *exit_status,
REBVAL *out,
const REBYTE *text,
REBOOL at_breakpoint
) {
struct Reb_State state;
REBCTX *error;
// Breakpoint REPLs are nested, and we may wish to jump out of them to
// the topmost level via a HALT. However, all other errors need to be
// confined, so that if one is doing evaluations during the pause of
// a breakpoint an error doesn't "accidentally resume" by virtue of
// jumping the stack out of the REPL.
//
// The topmost layer REPL, however, needs to catch halts in order to
// keep control and not crash out.
//
if (at_breakpoint)
PUSH_TRAP(&error, &state);
else
PUSH_UNHALTABLE_TRAP(&error, &state);
// The first time through the following code 'error' will be NULL, but...
// `fail` can longjmp here, so 'error' won't be NULL *if* that happens!
if (error) {
// Save error for WHY?
REBVAL *last = Get_System(SYS_STATE, STATE_LAST_ERROR);
if (ERR_NUM(error) == RE_HALT) {
assert(!at_breakpoint);
return -1; // !!! Revisit hardcoded #
}
Val_Init_Error(out, error);
*last = *out;
return -cast(REBINT, ERR_NUM(error));
}
REBARR *code = Scan_UTF8_Managed(text, LEN_BYTES(text));
// Where code ends up being bound when loaded at the REPL prompt should
// be more generally configurable. (It may be, for instance, that one
// wants to run something with it not bound at all.) Such choices
// must come from this REPL host...not from the interpreter itself.
{
// First the scanned code is bound into the user context with a
// fallback to the lib context.
//
// !!! This code is very old, and is how the REPL has bound since
// R3-Alpha. It comes from RL_Do_String, but should receive a modern
// review of why it's written exactly this way.
//
REBCTX *user_ctx = VAL_CONTEXT(Get_System(SYS_CONTEXTS, CTX_USER));
REBVAL vali;
SET_INTEGER(&vali, CTX_LEN(user_ctx) + 1);
Bind_Values_All_Deep(ARR_HEAD(code), user_ctx);
Resolve_Context(user_ctx, Lib_Context, &vali, FALSE, FALSE);
// If we're stopped at a breakpoint, the REPL should have a concept
// of what stack level it is inspecting (conveyed by the |#|>> in the
// prompt). This does a binding pass using the function for that
// stack level, just the way a body is bound during Make_Function()
//
if (at_breakpoint) {
REBVAL level;
SET_INTEGER(&level, HG_Stack_Level);
REBFRM *frame = Frame_For_Stack_Level(NULL, &level, FALSE);
assert(frame);
// Need to manage because it may be no words get bound into it,
// and we're not putting it into a FRAME! value, so it might leak
// otherwise if it's reified.
//
REBCTX *frame_ctx = Context_For_Frame_May_Reify_Managed(frame);
Bind_Values_Deep(ARR_HEAD(code), frame_ctx);
}
// !!! This was unused code that used to be in Do_String from
// RL_Api. It was an alternative path under `flags` which said
// "Bind into lib or user spaces?" and then "Top words will be
// added to lib". Is it relevant in any way?
//
/* Bind_Values_Set_Midstream_Shallow(ARR_HEAD(code), Lib_Context);
Bind_Values_Deep(ARR_HEAD(code), Lib_Context); */
}
if (Do_At_Throws(out, code, 0, SPECIFIED)) { // `code` will be GC protected
if (at_breakpoint) {
if (
IS_FUNCTION(out)
&& VAL_FUNC_DISPATCHER(out) == &N_resume
) {
//
// This means we're done with the embedded REPL. We want to
// resume and may be returning a piece of code that will be
// run by the finishing BREAKPOINT command in the target
// environment.
//
// We'll never return a halt, so we reuse -1 (in this very
// temporary scheme built on the very clunky historical REPL,
// which will not last much longer...fingers crossed.)
//
DROP_TRAP_SAME_STACKLEVEL_AS_PUSH(&state);
CATCH_THROWN(out, out);
*exit_status = -1;
return -1;
}
if (
IS_FUNCTION(out)
&& VAL_FUNC_DISPATCHER(out) == &N_quit
) {
//
// It would be frustrating if the system did not respond to
// a QUIT and forced you to do `resume/with [quit]`. So
// this is *not* caught, rather passed back up with the
// special -2 status code.
//
DROP_TRAP_SAME_STACKLEVEL_AS_PUSH(&state);
CATCH_THROWN(out, out);
*exit_status = -2;
return -2;
}
}
else {
// We are at the top level REPL, where we catch QUIT and for
// now, also EXIT as meaning you want to leave.
//
if (
IS_FUNCTION(out)
&& (
VAL_FUNC_DISPATCHER(out) == &N_quit
|| VAL_FUNC_DISPATCHER(out) == &N_exit
)
) {
DROP_TRAP_SAME_STACKLEVEL_AS_PUSH(&state);
CATCH_THROWN(out, out);
*exit_status = Exit_Status_From_Value(out);
return -2; // Revisit hardcoded #
}
}
fail (Error_No_Catch_For_Throw(out));
}
DROP_TRAP_SAME_STACKLEVEL_AS_PUSH(&state);
return 0;
}
