void for_loop_finish_iteration(Stack* context)
{
Frame* frame = top_frame(context);
Branch* contents = frame->branch;
// Find list length
caValue* listInput = get_frame_register(frame, 0);
// Increment the loop index
caValue* index = get_frame_register(frame, for_loop_find_index(contents)->index);
set_int(index, as_int(index) + 1);
// Check if we are finished
if (as_int(index) >= list_length(listInput)) {
frame->loop = false;
finish_frame(context);
return;
}
// If we're not finished yet, copy rebound outputs back to inputs.
for (int i=1;; i++) {
Term* input = get_input_placeholder(contents, i);
if (input == NULL)
break;
Term* output = get_output_placeholder(contents, i);
copy(get_frame_register(frame, output->index),
get_frame_register(frame, input->index));
}
// Return to start of loop body
frame->pc = 0;
frame->nextPc = 0;
}
void index_func_postCompile(Term* term)
{
Term* enclosingLoop = find_enclosing_for_loop(term);
if (enclosingLoop == NULL)
return;
Term* loop_index = for_loop_find_index(nested_contents(enclosingLoop));
if (loop_index == NULL)
return;
set_input(term, 0, loop_index);
set_input_hidden(term, 0, true);
}
void for_loop_fix_state_input(Branch* contents)
{
// This function will look at the state access inside for-loop contents.
// If there's state, the default building functions will have created
// terms that look like this:
//
// input() :state -> unpack_state -> pack_state -> output() :state
//
// We want each loop iteration to have its own state container. So we'll
// insert pack/unpack_state_list_n terms so that each iteration accesses
// state from a list. The result will look like:
//
// input() :state -> unpack_state_list_n(index) -> unpack_state -> pack_state
// -> pack_state_list_n(index) -> output() :state
// First insert the unpack_state_list_n call
Term* stateInput = find_state_input(contents);
// Nothing to do if there's no state input
if (stateInput == NULL)
return;
// Nothing to do if unpack_state_list_n term already exists
if (find_user_with_function(stateInput, FUNCS.unpack_state_list_n) != NULL)
return;
Term* unpackState = find_user_with_function(stateInput, FUNCS.unpack_state);
ca_assert(unpackState != NULL);
Term* index = for_loop_find_index(contents);
Term* unpackStateList = apply(contents, FUNCS.unpack_state_list_n,
TermList(stateInput, index));
transfer_users(stateInput, unpackStateList);
move_before(unpackStateList, unpackState);
set_input(unpackState, 0, unpackStateList);
// Now insert the pack_state_list_n call
Term* stateResult = find_open_state_result(contents, contents->length());
Term* packStateList = apply(contents, FUNCS.pack_state_list_n,
TermList(stateInput, stateResult, index));
packStateList->setBoolProp("final", true);
move_after(packStateList, stateResult);
// Make sure the state output uses this result
Term* stateOutput = append_state_output(contents);
set_input(stateOutput, 0, packStateList);
}
void start_for_loop(caStack* stack, bool enableLoopOutput)
{
Frame* frame = top_frame(stack);
Branch* contents = frame->branch;
// Check if top frame actually contains a for-loop (it might be using the #zero branch)
if (!is_for_loop(contents))
return;
// Initialize the loop index
set_int(get_frame_register(frame, for_loop_find_index(contents)), 0);
if (enableLoopOutput) {
// Initialize output value
set_int(get_frame_register(frame, for_loop_find_output_index(contents)), 0);
caValue* listInput = circa_input(stack, 0);
set_list(get_frame_register_from_end(frame, 0), list_length(listInput));
}
// Interpreter will run the contents of the branch
}
void for_loop_finish_iteration(Stack* stack, bool enableLoopOutput)
{
INCREMENT_STAT(LoopFinishIteration);
Frame* frame = top_frame(stack);
Branch* contents = frame->branch;
// Find list length
caValue* listInput = get_frame_register(frame, 0);
// Increment the loop index
caValue* index = get_top_register(stack, for_loop_find_index(contents));
set_int(index, as_int(index) + 1);
// Preserve list output
if (enableLoopOutput && frame->exitType != name_Discard) {
caValue* outputIndex = get_frame_register(frame, for_loop_find_output_index(contents));
Term* outputPlaceholder = get_output_placeholder(contents, 0);
caValue* outputList = get_frame_register(frame, outputPlaceholder);
caValue* outputValue = find_stack_value_for_term(stack, outputPlaceholder->input(0), 0);
if (!is_list(outputList))
set_list(outputList);
list_touch(outputList);
copy(outputValue, list_get(outputList, as_int(outputIndex)));
INCREMENT_STAT(LoopWriteOutput);
// Advance output index
set_int(outputIndex, as_int(outputIndex) + 1);
}
// Check if we are finished
if (as_int(index) >= list_length(listInput)
|| frame->exitType == name_Break
|| frame->exitType == name_Return) {
// Possibly truncate output list, in case any elements were discarded.
if (enableLoopOutput) {
caValue* outputIndex = get_frame_register(frame, for_loop_find_output_index(contents));
Term* outputPlaceholder = get_output_placeholder(contents, 0);
caValue* outputList = get_frame_register(frame, outputPlaceholder);
list_resize(outputList, as_int(outputIndex));
} else {
Term* outputPlaceholder = get_output_placeholder(contents, 0);
caValue* outputList = get_frame_register(frame, outputPlaceholder);
set_list(outputList, 0);
}
finish_frame(stack);
return;
}
// If we're not finished yet, copy rebound outputs back to inputs.
for (int i=1;; i++) {
Term* input = get_input_placeholder(contents, i);
if (input == NULL)
break;
Term* output = get_output_placeholder(contents, i);
copy(get_frame_register(frame, output),
get_frame_register(frame, input));
INCREMENT_STAT(Copy_LoopCopyRebound);
}
// Return to start of loop body
frame->pc = 0;
frame->nextPc = 0;
frame->exitType = name_None;
}
