//
// MAKE_Function: C
//
// For REB_FUNCTION and "make spec", there is a function spec block and then
// a block of Rebol code implementing that function. In that case we expect
// that `def` should be:
//
// [[spec] [body]]
//
// With REB_COMMAND, the code is implemented via a C DLL, under a system of
// APIs that pre-date Rebol's open sourcing and hence Ren/C:
//
// [[spec] extension command-num]
//
// See notes in Make_Command() regarding that mechanism and meaning.
//
void MAKE_Function(REBVAL *out, enum Reb_Kind kind, const REBVAL *arg)
{
assert(kind == REB_FUNCTION);
if (
!IS_BLOCK(arg)
|| VAL_LEN_AT(arg) != 2
|| !IS_BLOCK(VAL_ARRAY_AT(arg))
|| !IS_BLOCK(VAL_ARRAY_AT(arg) + 1)
){
fail (Error_Bad_Make(kind, arg));
}
REBVAL spec;
COPY_VALUE(&spec, VAL_ARRAY_AT(arg), VAL_SPECIFIER(arg));
REBVAL body;
COPY_VALUE(&body, VAL_ARRAY_AT(arg) + 1, VAL_SPECIFIER(arg));
// Spec-constructed functions do *not* have definitional returns
// added automatically. They are part of the generators. So the
// behavior comes--as with any other generator--from the projected
// code (though round-tripping it via text is not possible in
// general in any case due to loss of bindings.)
//
REBFUN *fun = Make_Interpreted_Function_May_Fail(
&spec, &body, MKF_ANY_VALUE
);
*out = *FUNC_VALUE(fun);
}
//
// Resolve_Path: C
//
// Given a path, determine if it is ultimately specifying a selection out
// of a context...and if it is, return that context. So `a/obj/key` would
// return the object assocated with obj, while `a/str/1` would return
// NULL if `str` were a string as it's not an object selection.
//
// !!! This routine overlaps the logic of Do_Path, and should potentially
// be a mode of that instead. It is not very complete, considering that it
// does not execute GROUP! (and perhaps shouldn't?) and only supports a
// path that picks contexts out of other contexts, via word selection.
//
REBCTX *Resolve_Path(const REBVAL *path, REBCNT *index_out)
{
RELVAL *selector;
const REBVAL *var;
REBARR *array;
REBCNT i;
array = VAL_ARRAY(path);
selector = ARR_HEAD(array);
if (IS_END(selector) || !ANY_WORD(selector))
return NULL; // !!! only handles heads of paths that are ANY-WORD!
var = GET_OPT_VAR_MAY_FAIL(selector, VAL_SPECIFIER(path));
++selector;
if (IS_END(selector))
return NULL; // !!! does not handle single-element paths
while (ANY_CONTEXT(var) && IS_WORD(selector)) {
i = Find_Canon_In_Context(
VAL_CONTEXT(var), VAL_WORD_CANON(selector), FALSE
);
++selector;
if (IS_END(selector)) {
*index_out = i;
return VAL_CONTEXT(var);
}
var = CTX_VAR(VAL_CONTEXT(var), i);
}
DEAD_END;
}
//
// TO_Vector: C
//
void TO_Vector(REBVAL *out, enum Reb_Kind kind, const REBVAL *arg)
{
if (IS_BLOCK(arg)) {
if (Make_Vector_Spec(VAL_ARRAY_AT(arg), VAL_SPECIFIER(arg), out))
return;
}
fail (Error_Bad_Make(kind, arg));
}
void Set_Vector_Row(REBSER *ser, REBVAL *blk)
{
REBCNT idx = VAL_INDEX(blk);
REBCNT len = VAL_LEN_AT(blk);
RELVAL *val;
REBCNT n = 0;
REBCNT bits = VECT_TYPE(ser);
REBI64 i = 0;
REBDEC f = 0;
if (IS_BLOCK(blk)) {
val = VAL_ARRAY_AT(blk);
for (; NOT_END(val); val++) {
if (IS_INTEGER(val)) {
i = VAL_INT64(val);
if (bits > VTUI64) f = (REBDEC)(i);
}
else if (IS_DECIMAL(val)) {
f = VAL_DECIMAL(val);
if (bits <= VTUI64) i = (REBINT)(f);
}
else fail (Error_Invalid_Arg_Core(val, VAL_SPECIFIER(blk)));
//if (n >= ser->tail) Expand_Vector(ser);
set_vect(bits, SER_DATA_RAW(ser), n++, i, f);
}
}
else {
REBYTE *data = VAL_BIN_AT(blk);
for (; len > 0; len--, idx++) {
set_vect(
bits, SER_DATA_RAW(ser), n++, cast(REBI64, data[idx]), f
);
}
}
}
//
// Modify_Array: C
//
// Returns new dst_idx
//
REBCNT Modify_Array(
REBCNT action, // INSERT, APPEND, CHANGE
REBARR *dst_arr, // target
REBCNT dst_idx, // position
const REBVAL *src_val, // source
REBCNT flags, // AN_ONLY, AN_PART
REBINT dst_len, // length to remove
REBINT dups // dup count
) {
REBCNT tail = ARR_LEN(dst_arr);
REBINT ilen = 1; // length to be inserted
const RELVAL *src_rel;
REBCTX *specifier;
if (IS_VOID(src_val) || dups < 0) {
// If they are effectively asking for "no action" then all we have
// to do is return the natural index result for the operation.
// (APPEND will return 0, insert the tail of the insertion...so index)
return (action == SYM_APPEND) ? 0 : dst_idx;
}
if (action == SYM_APPEND || dst_idx > tail) dst_idx = tail;
// Check /PART, compute LEN:
if (!GET_FLAG(flags, AN_ONLY) && ANY_ARRAY(src_val)) {
// Adjust length of insertion if changing /PART:
if (action != SYM_CHANGE && GET_FLAG(flags, AN_PART))
ilen = dst_len;
else
ilen = VAL_LEN_AT(src_val);
// Are we modifying ourselves? If so, copy src_val block first:
if (dst_arr == VAL_ARRAY(src_val)) {
REBARR *copy = Copy_Array_At_Shallow(
VAL_ARRAY(src_val), VAL_INDEX(src_val), VAL_SPECIFIER(src_val)
);
MANAGE_ARRAY(copy); // !!! Review: worth it to not manage and free?
src_rel = ARR_HEAD(copy);
specifier = SPECIFIED; // copy already specified it
}
else {
src_rel = VAL_ARRAY_AT(src_val); // skips by VAL_INDEX values
specifier = VAL_SPECIFIER(src_val);
}
}
else {
// use passed in RELVAL and specifier
src_rel = src_val;
specifier = SPECIFIED; // it's a REBVAL, not a RELVAL, so specified
}
REBINT size = dups * ilen; // total to insert
if (action != SYM_CHANGE) {
// Always expand dst_arr for INSERT and APPEND actions:
Expand_Series(ARR_SERIES(dst_arr), dst_idx, size);
}
else {
if (size > dst_len)
Expand_Series(ARR_SERIES(dst_arr), dst_idx, size-dst_len);
else if (size < dst_len && GET_FLAG(flags, AN_PART))
Remove_Series(ARR_SERIES(dst_arr), dst_idx, dst_len-size);
else if (size + dst_idx > tail) {
EXPAND_SERIES_TAIL(ARR_SERIES(dst_arr), size - (tail - dst_idx));
}
}
tail = (action == SYM_APPEND) ? 0 : size + dst_idx;
#if !defined(NDEBUG)
if (IS_ARRAY_MANAGED(dst_arr)) {
REBINT i;
for (i = 0; i < ilen; ++i)
ASSERT_VALUE_MANAGED(&src_rel[i]);
}
#endif
for (; dups > 0; dups--) {
REBINT index = 0;
for (; index < ilen; ++index, ++dst_idx) {
COPY_VALUE(
SINK(ARR_HEAD(dst_arr) + dst_idx),
src_rel + index,
specifier
);
}
}
TERM_ARRAY_LEN(dst_arr, ARR_LEN(dst_arr));
ASSERT_ARRAY(dst_arr);
return tail;
}
//
// Make_Set_Operation_Series: C
//
// Do set operations on a series. Case-sensitive if `cased` is TRUE.
// `skip` is the record size.
//
static REBSER *Make_Set_Operation_Series(
const REBVAL *val1,
const REBVAL *val2,
REBFLGS flags,
REBOOL cased,
REBCNT skip
) {
REBCNT i;
REBINT h = 1; // used for both logic true/false and hash check
REBOOL first_pass = TRUE; // are we in the first pass over the series?
REBSER *out_ser;
assert(ANY_SERIES(val1));
if (val2) {
assert(ANY_SERIES(val2));
if (ANY_ARRAY(val1)) {
if (!ANY_ARRAY(val2))
fail (Error_Unexpected_Type(VAL_TYPE(val1), VAL_TYPE(val2)));
// As long as they're both arrays, we're willing to do:
//
// >> union quote (a b c) 'b/d/e
// (a b c d e)
//
// The type of the result will match the first value.
}
else if (!IS_BINARY(val1)) {
// We will similarly do any two ANY-STRING! types:
//
// >> union <abc> "bde"
// <abcde>
if (IS_BINARY(val2))
fail (Error_Unexpected_Type(VAL_TYPE(val1), VAL_TYPE(val2)));
}
else {
// Binaries only operate with other binaries
if (!IS_BINARY(val2))
fail (Error_Unexpected_Type(VAL_TYPE(val1), VAL_TYPE(val2)));
}
}
// Calculate `i` as maximum length of result block. The temporary buffer
// will be allocated at this size, but copied out at the exact size of
// the actual result.
//
i = VAL_LEN_AT(val1);
if (flags & SOP_FLAG_BOTH) i += VAL_LEN_AT(val2);
if (ANY_ARRAY(val1)) {
REBSER *hser = 0; // hash table for series
REBSER *hret; // hash table for return series
// The buffer used for building the return series. Currently it
// reuses BUF_EMIT, because that buffer is not likely to be in
// use (emit doesn't call set operations, nor vice versa). However,
// other routines may get the same idea and start recursing so it
// may be better to use something more similar to the mold stack
// approach of marking off successive ranges in the array.
//
REBSER *buffer = ARR_SERIES(BUF_EMIT);
Resize_Series(buffer, i);
hret = Make_Hash_Sequence(i); // allocated
// Optimization note: !!
// This code could be optimized for small blocks by not hashing them
// and extending Find_Key to FIND on the value itself w/o the hash.
do {
REBARR *array1 = VAL_ARRAY(val1); // val1 and val2 swapped 2nd pass!
// Check what is in series1 but not in series2
//
if (flags & SOP_FLAG_CHECK)
hser = Hash_Block(val2, skip, cased);
// Iterate over first series
//
i = VAL_INDEX(val1);
for (; i < ARR_LEN(array1); i += skip) {
RELVAL *item = ARR_AT(array1, i);
if (flags & SOP_FLAG_CHECK) {
h = Find_Key_Hashed(
VAL_ARRAY(val2),
hser,
item,
VAL_SPECIFIER(val1),
skip,
cased,
1
);
h = (h >= 0);
if (flags & SOP_FLAG_INVERT) h = !h;
}
if (h) {
Find_Key_Hashed(
AS_ARRAY(buffer),
hret,
item,
VAL_SPECIFIER(val1),
skip,
cased,
2
);
}
}
if (i != ARR_LEN(array1)) {
//
// In the current philosophy, the semantics of what to do
// with things like `intersect/skip [1 2 3] [7] 2` is too
// shaky to deal with, so an error is reported if it does
// not work out evenly to the skip size.
//
fail (Error(RE_BLOCK_SKIP_WRONG));
}
if (flags & SOP_FLAG_CHECK)
Free_Series(hser);
if (!first_pass) break;
first_pass = FALSE;
// Iterate over second series?
//
if ((i = ((flags & SOP_FLAG_BOTH) != 0))) {
const REBVAL *temp = val1;
val1 = val2;
val2 = temp;
}
} while (i);
if (hret)
Free_Series(hret);
out_ser = ARR_SERIES(Copy_Array_Shallow(AS_ARRAY(buffer), SPECIFIED));
SET_SERIES_LEN(buffer, 0); // required - allow reuse
}
else {
REB_MOLD mo;
CLEARS(&mo);
if (IS_BINARY(val1)) {
//
// All binaries use "case-sensitive" comparison (e.g. each byte
// is treated distinctly)
//
cased = TRUE;
}
// ask mo.series to have at least `i` capacity beyond mo.start
//
mo.opts = MOPT_RESERVE;
mo.reserve = i;
Push_Mold(&mo);
do {
REBSER *ser = VAL_SERIES(val1); // val1 and val2 swapped 2nd pass!
REBUNI uc;
// Iterate over first series
//
i = VAL_INDEX(val1);
for (; i < SER_LEN(ser); i += skip) {
uc = GET_ANY_CHAR(ser, i);
if (flags & SOP_FLAG_CHECK) {
h = (NOT_FOUND != Find_Str_Char(
uc,
VAL_SERIES(val2),
0,
VAL_INDEX(val2),
VAL_LEN_HEAD(val2),
skip,
cased ? AM_FIND_CASE : 0
));
if (flags & SOP_FLAG_INVERT) h = !h;
}
if (!h) continue;
if (
NOT_FOUND == Find_Str_Char(
uc, // c2 (the character to find)
mo.series, // ser
mo.start, // head
mo.start, // index
SER_LEN(mo.series), // tail
skip, // skip
cased ? AM_FIND_CASE : 0 // flags
)
) {
Append_String(mo.series, ser, i, skip);
}
}
if (!first_pass) break;
first_pass = FALSE;
// Iterate over second series?
//
if ((i = ((flags & SOP_FLAG_BOTH) != 0))) {
const REBVAL *temp = val1;
val1 = val2;
val2 = temp;
}
} while (i);
out_ser = Pop_Molded_String(&mo);
}
return out_ser;
}
//
// Clonify: C
//
// Clone the series embedded in a value *if* it's in the given set of types
// (and if "cloning" makes sense for them, e.g. they are not simple scalars).
//
// Note: The resulting clones will be managed. The model for lists only
// allows the topmost level to contain unmanaged values...and we *assume* the
// values we are operating on here live inside of an array.
//
void Clonify(
REBVAL *v,
REBFLGS flags,
REBU64 types
){
if (C_STACK_OVERFLOWING(&types))
Fail_Stack_Overflow();
// !!! It may be possible to do this faster/better, the impacts on higher
// quoting levels could be incurring more cost than necessary...but for
// now err on the side of correctness. Unescape the value while cloning
// and then escape it back.
//
REBCNT num_quotes = VAL_NUM_QUOTES(v);
Dequotify(v);
enum Reb_Kind kind = cast(enum Reb_Kind, KIND_BYTE_UNCHECKED(v));
assert(kind < REB_MAX_PLUS_MAX); // we dequoted it (pseudotypes ok)
if (types & FLAGIT_KIND(kind) & TS_SERIES_OBJ) {
//
// Objects and series get shallow copied at minimum
//
REBSER *series;
if (ANY_CONTEXT(v)) {
INIT_VAL_CONTEXT_VARLIST(
v,
CTX_VARLIST(Copy_Context_Shallow_Managed(VAL_CONTEXT(v)))
);
series = SER(CTX_VARLIST(VAL_CONTEXT(v)));
}
else {
if (IS_SER_ARRAY(VAL_SERIES(v))) {
series = SER(
Copy_Array_At_Extra_Shallow(
VAL_ARRAY(v),
0, // !!! what if VAL_INDEX() is nonzero?
VAL_SPECIFIER(v),
0,
NODE_FLAG_MANAGED
)
);
INIT_VAL_NODE(v, series); // copies args
// If it was relative, then copying with a specifier
// means it isn't relative any more.
//
INIT_BINDING(v, UNBOUND);
}
else {
series = Copy_Sequence_Core(
VAL_SERIES(v),
NODE_FLAG_MANAGED
);
INIT_VAL_NODE(v, series);
}
}
// If we're going to copy deeply, we go back over the shallow
// copied series and "clonify" the values in it.
//
if (types & FLAGIT_KIND(kind) & TS_ARRAYS_OBJ) {
REBVAL *sub = KNOWN(ARR_HEAD(ARR(series)));
for (; NOT_END(sub); ++sub)
Clonify(sub, flags, types);
}
}
else if (types & FLAGIT_KIND(kind) & FLAGIT_KIND(REB_ACTION)) {
//
// !!! While Ren-C has abandoned the concept of copying the body
// of functions (they are black boxes which may not *have* a
// body), it would still theoretically be possible to do what
// COPY does and make a function with a new and independently
// hijackable identity. Assume for now it's better that the
// HIJACK of a method for one object will hijack it for all
// objects, and one must filter in the hijacking's body if one
// wants to take more specific action.
//
assert(false);
}
else {
// We're not copying the value, so inherit the const bit from the
// original value's point of view, if applicable.
//
if (NOT_CELL_FLAG(v, EXPLICITLY_MUTABLE))
v->header.bits |= (flags & ARRAY_FLAG_CONST_SHALLOW);
}
Quotify(v, num_quotes);
}
//
// Compose_Any_Array_Throws: C
//
// Compose a block from a block of un-evaluated values and GROUP! arrays that
// are evaluated. This calls into Do_Core, so if 'into' is provided, then its
// series must be protected from garbage collection.
//
// deep - recurse into sub-blocks
// only - parens that return blocks are kept as blocks
//
// Writes result value at address pointed to by out.
//
REBOOL Compose_Any_Array_Throws(
REBVAL *out,
const REBVAL *any_array,
REBOOL deep,
REBOOL only,
REBOOL into
) {
REBDSP dsp_orig = DSP;
Reb_Enumerator e;
PUSH_SAFE_ENUMERATOR(&e, any_array); // evaluating could disrupt any_array
while (NOT_END(e.value)) {
UPDATE_EXPRESSION_START(&e); // informs the error delivery better
if (IS_GROUP(e.value)) {
//
// We evaluate here, but disable lookahead so it only evaluates
// the GROUP! and doesn't trigger errors on what's after it.
//
REBVAL evaluated;
DO_NEXT_REFETCH_MAY_THROW(&evaluated, &e, DO_FLAG_NO_LOOKAHEAD);
if (THROWN(&evaluated)) {
*out = evaluated;
DS_DROP_TO(dsp_orig);
DROP_SAFE_ENUMERATOR(&e);
return TRUE;
}
if (IS_BLOCK(&evaluated) && !only) {
//
// compose [blocks ([a b c]) merge] => [blocks a b c merge]
//
RELVAL *push = VAL_ARRAY_AT(&evaluated);
while (NOT_END(push)) {
//
// `evaluated` is known to be specific, but its specifier
// may be needed to derelativize its children.
//
DS_PUSH_RELVAL(push, VAL_SPECIFIER(&evaluated));
push++;
}
}
else if (!IS_VOID(&evaluated)) {
//
// compose [(1 + 2) inserts as-is] => [3 inserts as-is]
// compose/only [([a b c]) unmerged] => [[a b c] unmerged]
//
DS_PUSH(&evaluated);
}
else {
//
// compose [(print "Voids *vanish*!")] => []
//
}
}
else if (deep) {
if (IS_BLOCK(e.value)) {
//
// compose/deep [does [(1 + 2)] nested] => [does [3] nested]
REBVAL specific;
COPY_VALUE(&specific, e.value, e.specifier);
REBVAL composed;
if (Compose_Any_Array_Throws(
&composed,
&specific,
TRUE,
only,
into
)) {
*out = composed;
DS_DROP_TO(dsp_orig);
DROP_SAFE_ENUMERATOR(&e);
return TRUE;
}
DS_PUSH(&composed);
}
else {
if (ANY_ARRAY(e.value)) {
//
// compose [copy/(orig) (copy)] => [copy/(orig) (copy)]
// !!! path and second group are copies, first group isn't
//
REBARR *copy = Copy_Array_Shallow(
VAL_ARRAY(e.value),
IS_RELATIVE(e.value)
? e.specifier // use parent specifier if relative...
: VAL_SPECIFIER(const_KNOWN(e.value)) // else child's
);
DS_PUSH_TRASH;
Val_Init_Array_Index(
DS_TOP, VAL_TYPE(e.value), copy, VAL_INDEX(e.value)
); // ...manages
}
else
DS_PUSH_RELVAL(e.value, e.specifier);
}
FETCH_NEXT_ONLY_MAYBE_END(&e);
}
else {
//
// compose [[(1 + 2)] (reverse "wollahs")] => [[(1 + 2)] "shallow"]
//
DS_PUSH_RELVAL(e.value, e.specifier);
FETCH_NEXT_ONLY_MAYBE_END(&e);
}
}
if (into)
Pop_Stack_Values_Into(out, dsp_orig);
else
Val_Init_Array(out, VAL_TYPE(any_array), Pop_Stack_Values(dsp_orig));
DROP_SAFE_ENUMERATOR(&e);
return FALSE;
}
//
// MAKE_Decimal: C
//
void MAKE_Decimal(REBVAL *out, enum Reb_Kind kind, const REBVAL *arg) {
REBDEC d;
switch (VAL_TYPE(arg)) {
case REB_DECIMAL:
d = VAL_DECIMAL(arg);
goto dont_divide_if_percent;
case REB_PERCENT:
d = VAL_DECIMAL(arg);
goto dont_divide_if_percent;
case REB_INTEGER:
d = cast(REBDEC, VAL_INT64(arg));
goto dont_divide_if_percent;
case REB_MONEY:
d = deci_to_decimal(VAL_MONEY_AMOUNT(arg));
goto dont_divide_if_percent;
case REB_LOGIC:
d = VAL_LOGIC(arg) ? 1.0 : 0.0;
goto dont_divide_if_percent;
case REB_CHAR:
d = cast(REBDEC, VAL_CHAR(arg));
goto dont_divide_if_percent;
case REB_TIME:
d = VAL_TIME(arg) * NANO;
break;
case REB_STRING:
{
REBYTE *bp;
REBCNT len;
bp = Temp_Byte_Chars_May_Fail(arg, MAX_SCAN_DECIMAL, &len, FALSE);
VAL_RESET_HEADER(out, kind);
if (!Scan_Decimal(
&d, bp, len, LOGICAL(kind != REB_PERCENT)
)) {
goto bad_make;
}
break;
}
case REB_BINARY:
Binary_To_Decimal(arg, out);
VAL_RESET_HEADER(out, kind);
d = VAL_DECIMAL(out);
break;
#ifdef removed
// case REB_ISSUE:
{
REBYTE *bp;
REBCNT len;
bp = Temp_Byte_Chars_May_Fail(arg, MAX_HEX_LEN, &len, FALSE);
if (Scan_Hex(&VAL_INT64(out), bp, len, len) == 0)
fail (Error_Bad_Make(REB_DECIMAL, val));
d = VAL_DECIMAL(out);
break;
}
#endif
default:
if (ANY_ARRAY(arg) && VAL_ARRAY_LEN_AT(arg) == 2) {
RELVAL *item = VAL_ARRAY_AT(arg);
if (IS_INTEGER(item))
d = cast(REBDEC, VAL_INT64(item));
else if (IS_DECIMAL(item) || IS_PERCENT(item))
d = VAL_DECIMAL(item);
else {
REBVAL specific;
COPY_VALUE(&specific, item, VAL_SPECIFIER(arg));
fail (Error_Invalid_Arg(&specific));
}
++item;
REBDEC exp;
if (IS_INTEGER(item))
exp = cast(REBDEC, VAL_INT64(item));
else if (IS_DECIMAL(item) || IS_PERCENT(item))
exp = VAL_DECIMAL(item);
else {
REBVAL specific;
COPY_VALUE(&specific, item, VAL_SPECIFIER(arg));
fail (Error_Invalid_Arg(&specific));
}
while (exp >= 1) {
//
// !!! Comment here said "funky. There must be a better way"
//
--exp;
d *= 10.0;
if (!FINITE(d))
fail (Error(RE_OVERFLOW));
}
while (exp <= -1) {
++exp;
d /= 10.0;
}
}
else
fail (Error_Bad_Make(kind, arg));
}
if (kind == REB_PERCENT)
d /= 100.0;
dont_divide_if_percent:
if (!FINITE(d))
fail (Error(RE_OVERFLOW));
VAL_RESET_HEADER(out, kind);
VAL_DECIMAL(out) = d;
return;
bad_make:
fail (Error_Bad_Make(kind, arg));
}
//
// Next_Path_Throws: C
//
// Evaluate next part of a path.
//
REBOOL Next_Path_Throws(REBPVS *pvs)
{
REBPEF dispatcher;
// Path must have dispatcher, else return:
dispatcher = Path_Dispatch[VAL_TYPE(pvs->value)];
if (!dispatcher) return FALSE; // unwind, then check for errors
pvs->item++;
//Debug_Fmt("Next_Path: %r/%r", pvs->path-1, pvs->path);
// Determine the "selector". See notes on pvs->selector_temp for why
// a local variable can't be used for the temporary space.
//
if (IS_GET_WORD(pvs->item)) { // e.g. object/:field
pvs->selector
= GET_MUTABLE_VAR_MAY_FAIL(pvs->item, pvs->item_specifier);
if (IS_VOID(pvs->selector))
fail (Error_No_Value_Core(pvs->item, pvs->item_specifier));
SET_TRASH_IF_DEBUG(&pvs->selector_temp);
}
// object/(expr) case:
else if (IS_GROUP(pvs->item)) {
if (Do_At_Throws(
&pvs->selector_temp,
VAL_ARRAY(pvs->item),
VAL_INDEX(pvs->item),
IS_RELATIVE(pvs->item)
? pvs->item_specifier // if relative, use parent specifier...
: VAL_SPECIFIER(const_KNOWN(pvs->item)) // ...else use child's
)) {
*pvs->store = pvs->selector_temp;
return TRUE;
}
pvs->selector = &pvs->selector_temp;
}
else {
// object/word and object/value case:
//
COPY_VALUE(&pvs->selector_temp, pvs->item, pvs->item_specifier);
pvs->selector = &pvs->selector_temp;
}
switch (dispatcher(pvs)) {
case PE_OK:
break;
case PE_SET_IF_END:
if (pvs->opt_setval && IS_END(pvs->item + 1)) {
*pvs->value = *pvs->opt_setval;
pvs->opt_setval = NULL;
}
break;
case PE_NONE:
SET_BLANK(pvs->store);
case PE_USE_STORE:
pvs->value = pvs->store;
pvs->value_specifier = SPECIFIED;
break;
default:
assert(FALSE);
}
if (NOT_END(pvs->item + 1)) return Next_Path_Throws(pvs);
return FALSE;
}
//
// Do_Path_Throws_Core: C
//
// Evaluate an ANY_PATH! REBVAL, starting from the index position of that
// path value and continuing to the end.
//
// The evaluator may throw because GROUP! is evaluated, e.g. `foo/(throw 1020)`
//
// If label_sym is passed in as being non-null, then the caller is implying
// readiness to process a path which may be a function with refinements.
// These refinements will be left in order on the data stack in the case
// that `out` comes back as IS_FUNCTION().
//
// If `opt_setval` is given, the path operation will be done as a "SET-PATH!"
// if the path evaluation did not throw or error. HOWEVER the set value
// is NOT put into `out`. This provides more flexibility on performance in
// the evaluator, which may already have the `val` where it wants it, and
// so the extra assignment would just be overhead.
//
// !!! Path evaluation is one of the parts of R3-Alpha that has not been
// vetted very heavily by Ren-C, and needs a review and overhaul.
//
REBOOL Do_Path_Throws_Core(
REBVAL *out,
REBSTR **label_out,
const RELVAL *path,
REBCTX *specifier,
REBVAL *opt_setval
) {
REBPVS pvs;
REBDSP dsp_orig = DSP;
assert(ANY_PATH(path));
// !!! There is a bug in the dispatch such that if you are running a
// set path, it does not always assign the output, because it "thinks you
// aren't going to look at it". This presumably originated from before
// parens were allowed in paths, and neglects cases like:
//
// foo/(throw 1020): value
//
// We always have to check to see if a throw occurred. Until this is
// streamlined, we have to at minimum set it to something that is *not*
// thrown so that we aren't testing uninitialized memory. A safe trash
// will do, which is unset in release builds.
//
if (opt_setval)
SET_TRASH_SAFE(out);
// None of the values passed in can live on the data stack, because
// they might be relocated during the path evaluation process.
//
assert(!IN_DATA_STACK_DEBUG(out));
assert(!IN_DATA_STACK_DEBUG(path));
assert(!opt_setval || !IN_DATA_STACK_DEBUG(opt_setval));
// Not currently robust for reusing passed in path or value as the output
assert(out != path && out != opt_setval);
assert(!opt_setval || !THROWN(opt_setval));
// Initialize REBPVS -- see notes in %sys-do.h
//
pvs.opt_setval = opt_setval;
pvs.store = out;
pvs.orig = path;
pvs.item = VAL_ARRAY_AT(pvs.orig); // may not be starting at head of PATH!
// The path value that's coming in may be relative (in which case it
// needs to use the specifier passed in). Or it may be specific already,
// in which case we should use the specifier in the value to process
// its array contents.
//
if (IS_RELATIVE(path)) {
#if !defined(NDEBUG)
assert(specifier != SPECIFIED);
if (VAL_RELATIVE(path) != VAL_FUNC(CTX_FRAME_FUNC_VALUE(specifier))) {
Debug_Fmt("Specificity mismatch found in path dispatch");
PROBE_MSG(path, "the path being evaluated");
PROBE_MSG(FUNC_VALUE(VAL_RELATIVE(path)), "expected func");
PROBE_MSG(CTX_FRAME_FUNC_VALUE(specifier), "actual func");
assert(FALSE);
}
#endif
pvs.item_specifier = specifier;
}
else pvs.item_specifier = VAL_SPECIFIER(const_KNOWN(path));
// Seed the path evaluation process by looking up the first item (to
// get a datatype to dispatch on for the later path items)
//
if (IS_WORD(pvs.item)) {
pvs.value = GET_MUTABLE_VAR_MAY_FAIL(pvs.item, pvs.item_specifier);
pvs.value_specifier = SPECIFIED;
if (IS_VOID(pvs.value))
fail (Error_No_Value_Core(pvs.item, pvs.item_specifier));
}
else {
// !!! Ideally there would be some way to deal with writes to
// temporary locations, like this pvs.value...if a set-path sets
// it, then it will be discarded.
COPY_VALUE(pvs.store, VAL_ARRAY_AT(pvs.orig), pvs.item_specifier);
pvs.value = pvs.store;
pvs.value_specifier = SPECIFIED;
}
// Start evaluation of path:
if (IS_END(pvs.item + 1)) {
// If it was a single element path, return the value rather than
// try to dispatch it (would cause a crash at time of writing)
//
// !!! Is this the desired behavior, or should it be an error?
}
else if (Path_Dispatch[VAL_TYPE(pvs.value)]) {
REBOOL threw = Next_Path_Throws(&pvs);
// !!! See comments about why the initialization of out is necessary.
// Without it this assertion can change on some things:
//
// t: now
// t/time: 10:20:03
//
// (It thinks pvs.value has its THROWN bit set when it completed
// successfully. It was a PE_USE_STORE case where pvs.value was reset to
// pvs.store, and pvs.store has its thrown bit set. Valgrind does not
// catch any uninitialized variables.)
//
// There are other cases that do trip valgrind when omitting the
// initialization, though not as clearly reproducible.
//
assert(threw == THROWN(pvs.value));
if (threw) return TRUE;
// Check for errors:
if (NOT_END(pvs.item + 1) && !IS_FUNCTION(pvs.value)) {
//
// Only function refinements should get by this line:
REBVAL specified_orig;
COPY_VALUE(&specified_orig, pvs.orig, specifier);
REBVAL specified_item;
COPY_VALUE(&specified_item, pvs.item, specifier);
fail (Error(RE_INVALID_PATH, &specified_orig, &specified_item));
}
}
else if (!IS_FUNCTION(pvs.value)) {
REBVAL specified;
COPY_VALUE(&specified, pvs.orig, specifier);
fail (Error(RE_BAD_PATH_TYPE, &specified, Type_Of(pvs.value)));
}
if (opt_setval) {
// If SET then we don't return anything
assert(IS_END(pvs.item) + 1);
return FALSE;
}
// If storage was not used, then copy final value back to it:
if (pvs.value != pvs.store)
COPY_VALUE(pvs.store, pvs.value, pvs.value_specifier);
assert(!THROWN(out));
// Return 0 if not function or is :path/word...
if (!IS_FUNCTION(pvs.value)) {
assert(IS_END(pvs.item) + 1);
return FALSE;
}
if (label_out) {
REBVAL refinement;
// When a function is hit, path processing stops as soon as the
// processed sub-path resolves to a function. The path is still sitting
// on the position of the last component of that sub-path. Usually,
// this last component in the sub-path is a word naming the function.
//
if (IS_WORD(pvs.item)) {
*label_out = VAL_WORD_SPELLING(pvs.item);
}
else {
// In rarer cases, the final component (completing the sub-path to
// the function to call) is not a word. Such as when you use a path
// to pick by index out of a block of functions:
//
// functions: reduce [:add :subtract]
// functions/1 10 20
//
// Or when you have an immediate function value in a path with a
// refinement. Tricky to make, but possible:
//
// do reduce [
// to-path reduce [:append 'only] [a] [b]
// ]
//
// !!! When a function was not invoked through looking up a word
// (or a word in a path) to use as a label, there were once three
// different alternate labels used. One was SYM__APPLY_, another
// was ROOT_NONAME, and another was to be the type of the function
// being executed. None are fantastic, we do the type for now.
*label_out = Canon(SYM_FROM_KIND(VAL_TYPE(pvs.value)));
}
// Move on to the refinements (if any)
++pvs.item;
// !!! Currently, the mainline path evaluation "punts" on refinements.
// When it finds a function, it stops the path evaluation and leaves
// the position pvs.path before the list of refinements.
//
// A more elegant solution would be able to process and notice (for
// instance) that `:APPEND/ONLY` should yield a function value that
// has been specialized with a refinement. Path chaining should thus
// be able to effectively do this and give the refined function object
// back to the evaluator or other client.
//
// If a label_sym is passed in, we recognize that a function dispatch
// is going to be happening. We do not want to pay to generate the
// new series that would be needed to make a temporary function that
// will be invoked and immediately GC'd So we gather the refinements
// on the data stack.
//
// This code simulates that path-processing-to-data-stack, but it
// should really be something in dispatch iself. In any case, we put
// refinements on the data stack...and caller knows refinements are
// from dsp_orig to DSP (thanks to accounting, all other operations
// should balance!)
for (; NOT_END(pvs.item); ++pvs.item) { // "the refinements"
if (IS_VOID(pvs.item)) continue;
if (IS_GROUP(pvs.item)) {
//
// Note it is not legal to use the data stack directly as the
// output location for a DO (might be resized)
if (Do_At_Throws(
&refinement,
VAL_ARRAY(pvs.item),
VAL_INDEX(pvs.item),
IS_RELATIVE(pvs.item)
? pvs.item_specifier // if relative, use parent's
: VAL_SPECIFIER(const_KNOWN(pvs.item)) // else embedded
)) {
*out = refinement;
DS_DROP_TO(dsp_orig);
return TRUE;
}
if (IS_VOID(&refinement)) continue;
DS_PUSH(&refinement);
}
else if (IS_GET_WORD(pvs.item)) {
DS_PUSH_TRASH;
*DS_TOP = *GET_OPT_VAR_MAY_FAIL(pvs.item, pvs.item_specifier);
if (IS_VOID(DS_TOP)) {
DS_DROP;
continue;
}
}
else DS_PUSH_RELVAL(pvs.item, pvs.item_specifier);
// Whatever we were trying to use as a refinement should now be
// on the top of the data stack, and only words are legal ATM
//
if (!IS_WORD(DS_TOP)) {
fail (Error(RE_BAD_REFINE, DS_TOP));
}
// Go ahead and canonize the word symbol so we don't have to
// do it each time in order to get a case-insenstive compare
//
INIT_WORD_SPELLING(DS_TOP, VAL_WORD_CANON(DS_TOP));
}
// To make things easier for processing, reverse the refinements on
// the data stack (we needed to evaluate them in forward order).
// This way we can just pop them as we go, and know if they weren't
// all consumed if it doesn't get back to `dsp_orig` by the end.
if (dsp_orig != DSP) {
REBVAL *bottom = DS_AT(dsp_orig + 1);
REBVAL *top = DS_TOP;
while (top > bottom) {
refinement = *bottom;
*bottom = *top;
*top = refinement;
top--;
bottom++;
}
}
}
else {
// !!! Historically this just ignores a result indicating this is a
// function with refinements, e.g. ':append/only'. However that
// ignoring seems unwise. It should presumably create a modified
// function in that case which acts as if it has the refinement.
//
// If the caller did not pass in a label pointer we assume they are
// likely not ready to process any refinements.
//
if (NOT_END(pvs.item + 1))
fail (Error(RE_TOO_LONG)); // !!! Better error or add feature
}
return FALSE;
}