*/ static REB_R Loop_Each(struct Reb_Call *call_, REBINT mode)
/*
** Supports these natives (modes):
** 0: foreach
** 1: remove-each
** 2: map
**
***********************************************************************/
{
REBSER *body;
REBVAL *vars;
REBVAL *words;
REBSER *frame;
REBVAL *value;
REBSER *series;
REBSER *out; // output block (for MAP, mode = 2)
REBINT index; // !!!! should these be REBCNT?
REBINT tail;
REBINT windex; // write
REBINT rindex; // read
REBINT err;
REBCNT i;
REBCNT j;
REBVAL *ds;
assert(mode >= 0 && mode < 3);
value = D_ARG(2); // series
if (IS_NONE(value)) return R_NONE;
body = Init_Loop(D_ARG(1), D_ARG(3), &frame); // vars, body
SET_OBJECT(D_ARG(1), frame); // keep GC safe
Set_Block(D_ARG(3), body); // keep GC safe
SET_NONE(D_OUT); // Default result to NONE if the loop does not run
// If it's MAP, create result block:
if (mode == 2) {
out = Make_Block(VAL_LEN(value));
SAVE_SERIES(out);
}
// Get series info:
if (ANY_OBJECT(value)) {
series = VAL_OBJ_FRAME(value);
out = FRM_WORD_SERIES(series); // words (the out local reused)
index = 1;
//if (frame->tail > 3) Trap_Arg_DEAD_END(FRM_WORD(frame, 3));
}
else if (IS_MAP(value)) {
series = VAL_SERIES(value);
index = 0;
//if (frame->tail > 3) Trap_Arg_DEAD_END(FRM_WORD(frame, 3));
}
else {
series = VAL_SERIES(value);
index = VAL_INDEX(value);
if (index >= cast(REBINT, SERIES_TAIL(series))) {
if (mode == 1) {
SET_INTEGER(D_OUT, 0);
} else if (mode == 2) {
Set_Block(D_OUT, out);
UNSAVE_SERIES(out);
}
return R_OUT;
}
}
windex = index;
// Iterate over each value in the series block:
while (index < (tail = SERIES_TAIL(series))) {
rindex = index; // remember starting spot
j = 0;
// Set the FOREACH loop variables from the series:
for (i = 1; i < frame->tail; i++) {
vars = FRM_VALUE(frame, i);
words = FRM_WORD(frame, i);
// var spec is WORD
if (IS_WORD(words)) {
if (index < tail) {
if (ANY_BLOCK(value)) {
*vars = *BLK_SKIP(series, index);
}
else if (ANY_OBJECT(value)) {
if (!VAL_GET_EXT(BLK_SKIP(out, index), EXT_WORD_HIDE)) {
// Alternate between word and value parts of object:
if (j == 0) {
Init_Word(vars, REB_WORD, VAL_WORD_SYM(BLK_SKIP(out, index)), series, index);
if (NOT_END(vars+1)) index--; // reset index for the value part
}
else if (j == 1)
*vars = *BLK_SKIP(series, index);
else
Trap_Arg_DEAD_END(words);
j++;
}
else {
// Do not evaluate this iteration
index++;
goto skip_hidden;
}
}
else if (IS_VECTOR(value)) {
Set_Vector_Value(vars, series, index);
}
else if (IS_MAP(value)) {
REBVAL *val = BLK_SKIP(series, index | 1);
if (!IS_NONE(val)) {
if (j == 0) {
*vars = *BLK_SKIP(series, index & ~1);
if (IS_END(vars+1)) index++; // only words
}
else if (j == 1)
*vars = *BLK_SKIP(series, index);
else
Trap_Arg_DEAD_END(words);
j++;
}
else {
index += 2;
goto skip_hidden;
}
}
else { // A string or binary
if (IS_BINARY(value)) {
SET_INTEGER(vars, (REBI64)(BIN_HEAD(series)[index]));
}
else if (IS_IMAGE(value)) {
Set_Tuple_Pixel(BIN_SKIP(series, index), vars);
}
else {
VAL_SET(vars, REB_CHAR);
VAL_CHAR(vars) = GET_ANY_CHAR(series, index);
}
}
index++;
}
else SET_NONE(vars);
}
// var spec is SET_WORD:
else if (IS_SET_WORD(words)) {
if (ANY_OBJECT(value) || IS_MAP(value)) {
*vars = *value;
} else {
VAL_SET(vars, REB_BLOCK);
VAL_SERIES(vars) = series;
VAL_INDEX(vars) = index;
}
//if (index < tail) index++; // do not increment block.
}
else Trap_Arg_DEAD_END(words);
}
if (index == rindex) index++; //the word block has only set-words: foreach [a:] [1 2 3][]
if (!DO_BLOCK(D_OUT, body, 0)) {
if ((err = Check_Error(D_OUT)) >= 0) {
index = rindex;
break;
}
// else CONTINUE:
if (mode == 1) SET_FALSE(D_OUT); // keep the value (for mode == 1)
} else {
err = 0; // prevent later test against uninitialized value
}
if (mode > 0) {
//if (ANY_OBJECT(value)) Trap_Types_DEAD_END(words, REB_BLOCK, VAL_TYPE(value)); //check not needed
// If FALSE return, copy values to the write location:
if (mode == 1) { // remove-each
if (IS_CONDITIONAL_FALSE(D_OUT)) {
REBCNT wide = SERIES_WIDE(series);
// memory areas may overlap, so use memmove and not memcpy!
memmove(series->data + (windex * wide), series->data + (rindex * wide), (index - rindex) * wide);
windex += index - rindex;
// old: while (rindex < index) *BLK_SKIP(series, windex++) = *BLK_SKIP(series, rindex++);
}
}
else
if (!IS_UNSET(D_OUT)) Append_Value(out, D_OUT); // (mode == 2)
}
skip_hidden: ;
}
// Finish up:
if (mode == 1) {
// Remove hole (updates tail):
if (windex < index) Remove_Series(series, windex, index - windex);
SET_INTEGER(D_OUT, index - windex);
return R_OUT;
}
// If MAP...
if (mode == 2) {
UNSAVE_SERIES(out);
if (err != 2) {
// ...and not BREAK/RETURN:
Set_Block(D_OUT, out);
return R_OUT;
}
}
return R_OUT;
}
*/ static REB_R Loop_Each(struct Reb_Call *call_, LOOP_MODE mode)
/*
** Common implementation code of FOR-EACH, REMOVE-EACH, MAP-EACH,
** and EVERY.
**
***********************************************************************/
{
REBSER *body;
REBVAL *vars;
REBVAL *words;
REBSER *frame;
// `data` is the series/object/map/etc. being iterated over
// Note: `data_is_object` flag is optimized out, but hints static analyzer
REBVAL *data = D_ARG(2);
REBSER *series;
const REBOOL data_is_object = ANY_OBJECT(data);
REBSER *out; // output block (needed for MAP-EACH)
REBINT index; // !!!! should these be REBCNT?
REBINT tail;
REBINT windex; // write
REBINT rindex; // read
REBOOL break_with = FALSE;
REBOOL every_true = TRUE;
REBCNT i;
REBCNT j;
REBVAL *ds;
if (IS_NONE(data)) return R_NONE;
body = Init_Loop(D_ARG(1), D_ARG(3), &frame); // vars, body
Val_Init_Object(D_ARG(1), frame); // keep GC safe
Val_Init_Block(D_ARG(3), body); // keep GC safe
SET_NONE(D_OUT); // Default result to NONE if the loop does not run
if (mode == LOOP_MAP_EACH) {
// Must be managed *and* saved...because we are accumulating results
// into it, and those results must be protected from GC
// !!! This means we cannot Free_Series in case of a BREAK, we
// have to leave it to the GC. Should there be a variant which
// lets a series be a GC root for a temporary time even if it is
// not SER_KEEP?
out = Make_Array(VAL_LEN(data));
MANAGE_SERIES(out);
SAVE_SERIES(out);
}
// Get series info:
if (data_is_object) {
series = VAL_OBJ_FRAME(data);
out = FRM_WORD_SERIES(series); // words (the out local reused)
index = 1;
//if (frame->tail > 3) raise Error_Invalid_Arg(FRM_WORD(frame, 3));
}
else if (IS_MAP(data)) {
series = VAL_SERIES(data);
index = 0;
//if (frame->tail > 3) raise Error_Invalid_Arg(FRM_WORD(frame, 3));
}
else {
series = VAL_SERIES(data);
index = VAL_INDEX(data);
if (index >= cast(REBINT, SERIES_TAIL(series))) {
if (mode == LOOP_REMOVE_EACH) {
SET_INTEGER(D_OUT, 0);
}
else if (mode == LOOP_MAP_EACH) {
UNSAVE_SERIES(out);
Val_Init_Block(D_OUT, out);
}
return R_OUT;
}
}
windex = index;
// Iterate over each value in the data series block:
while (index < (tail = SERIES_TAIL(series))) {
rindex = index; // remember starting spot
j = 0;
// Set the FOREACH loop variables from the series:
for (i = 1; i < frame->tail; i++) {
vars = FRM_VALUE(frame, i);
words = FRM_WORD(frame, i);
// var spec is WORD
if (IS_WORD(words)) {
if (index < tail) {
if (ANY_BLOCK(data)) {
*vars = *BLK_SKIP(series, index);
}
else if (data_is_object) {
if (!VAL_GET_EXT(BLK_SKIP(out, index), EXT_WORD_HIDE)) {
// Alternate between word and value parts of object:
if (j == 0) {
Val_Init_Word(vars, REB_WORD, VAL_WORD_SYM(BLK_SKIP(out, index)), series, index);
if (NOT_END(vars+1)) index--; // reset index for the value part
}
else if (j == 1)
*vars = *BLK_SKIP(series, index);
else
raise Error_Invalid_Arg(words);
j++;
}
else {
// Do not evaluate this iteration
index++;
goto skip_hidden;
}
}
else if (IS_VECTOR(data)) {
Set_Vector_Value(vars, series, index);
}
else if (IS_MAP(data)) {
REBVAL *val = BLK_SKIP(series, index | 1);
if (!IS_NONE(val)) {
if (j == 0) {
*vars = *BLK_SKIP(series, index & ~1);
if (IS_END(vars+1)) index++; // only words
}
else if (j == 1)
*vars = *BLK_SKIP(series, index);
else
raise Error_Invalid_Arg(words);
j++;
}
else {
index += 2;
goto skip_hidden;
}
}
else { // A string or binary
if (IS_BINARY(data)) {
SET_INTEGER(vars, (REBI64)(BIN_HEAD(series)[index]));
}
else if (IS_IMAGE(data)) {
Set_Tuple_Pixel(BIN_SKIP(series, index), vars);
}
else {
VAL_SET(vars, REB_CHAR);
VAL_CHAR(vars) = GET_ANY_CHAR(series, index);
}
}
index++;
}
else SET_NONE(vars);
}
// var spec is SET_WORD:
else if (IS_SET_WORD(words)) {
if (ANY_OBJECT(data) || IS_MAP(data))
*vars = *data;
else
Val_Init_Block_Index(vars, series, index);
//if (index < tail) index++; // do not increment block.
}
else
raise Error_Invalid_Arg(words);
}
if (index == rindex) {
// the word block has only set-words: for-each [a:] [1 2 3][]
index++;
}
if (Do_Block_Throws(D_OUT, body, 0)) {
if (IS_WORD(D_OUT) && VAL_WORD_SYM(D_OUT) == SYM_CONTINUE) {
if (mode == LOOP_REMOVE_EACH) {
// signal the post-body-execution processing that we
// *do not* want to remove the element on a CONTINUE
SET_FALSE(D_OUT);
}
else {
// CONTINUE otherwise acts "as if" the loop body execution
// returned an UNSET!
SET_UNSET(D_OUT);
}
}
else if (IS_WORD(D_OUT) && VAL_WORD_SYM(D_OUT) == SYM_BREAK) {
// If it's a BREAK, get the /WITH value (UNSET! if no /WITH)
// Though technically this doesn't really tell us if a
// BREAK/WITH happened, as you can BREAK/WITH an UNSET!
TAKE_THROWN_ARG(D_OUT, D_OUT);
if (!IS_UNSET(D_OUT))
break_with = TRUE;
index = rindex;
break;
}
else {
// Any other kind of throw, with a WORD! name or otherwise...
index = rindex;
break;
}
}
switch (mode) {
case LOOP_FOR_EACH:
// no action needed after body is run
break;
case LOOP_REMOVE_EACH:
// If FALSE return, copy values to the write location
// !!! Should UNSET! also act as conditional false here? Error?
if (IS_CONDITIONAL_FALSE(D_OUT)) {
REBYTE wide = SERIES_WIDE(series);
// memory areas may overlap, so use memmove and not memcpy!
// !!! This seems a slow way to do it, but there's probably
// not a lot that can be done as the series is expected to
// be in a good state for the next iteration of the body. :-/
memmove(
series->data + (windex * wide),
series->data + (rindex * wide),
(index - rindex) * wide
);
windex += index - rindex;
}
break;
case LOOP_MAP_EACH:
// anything that's not an UNSET! will be added to the result
if (!IS_UNSET(D_OUT)) Append_Value(out, D_OUT);
break;
case LOOP_EVERY:
if (every_true) {
// !!! This currently treats UNSET! as true, which ALL
// effectively does right now. That's likely a bad idea.
// When ALL changes, so should this.
//
every_true = IS_CONDITIONAL_TRUE(D_OUT);
}
break;
default:
assert(FALSE);
}
skip_hidden: ;
}
switch (mode) {
case LOOP_FOR_EACH:
// Nothing to do but return last result (will be UNSET! if an
// ordinary BREAK was used, the /WITH if a BREAK/WITH was used,
// and an UNSET! if the last loop iteration did a CONTINUE.)
return R_OUT;
case LOOP_REMOVE_EACH:
// Remove hole (updates tail):
if (windex < index) Remove_Series(series, windex, index - windex);
SET_INTEGER(D_OUT, index - windex);
return R_OUT;
case LOOP_MAP_EACH:
UNSAVE_SERIES(out);
if (break_with) {
// If BREAK is given a /WITH parameter that is not an UNSET!, it
// is assumed that you want to override the accumulated mapped
// data so far and return the /WITH value. (which will be in
// D_OUT when the loop above is `break`-ed)
// !!! Would be nice if we could Free_Series(out), but it is owned
// by GC (we had to make it that way to use SAVE_SERIES on it)
return R_OUT;
}
// If you BREAK/WITH an UNSET! (or just use a BREAK that has no
// /WITH, which is indistinguishable in the thrown value) then it
// returns the accumulated results so far up to the break.
Val_Init_Block(D_OUT, out);
return R_OUT;
case LOOP_EVERY:
// Result is the cumulative TRUE? state of all the input (with any
// unsets taken out of the consideration). The last TRUE? input
// if all valid and NONE! otherwise. (Like ALL.) If the loop
// never runs, `every_true` will be TRUE *but* D_OUT will be NONE!
if (!every_true)
SET_NONE(D_OUT);
return R_OUT;
}
DEAD_END;
}