// Parse {block} [else {block}]
static void parse_block_else_block(bool parse_first) {
// Parse first block.
// If it's not correctly terminated, return immediately (because
// in that case, there's no use in checking for an "else" part).
if(skip_or_parse_block(parse_first))
return;
// now GotByte = '}'. Check for "else" part.
// If end of statement, return immediately.
NEXTANDSKIPSPACE();
if(GotByte == CHAR_EOS)
return;
// read keyword and check whether really "else"
if(Input_read_and_lower_keyword()) {
if(strcmp(GlobalDynaBuf->buffer, "else"))
Throw_error(exception_syntax);
else {
SKIPSPACE();
if(GotByte != CHAR_SOB)
Throw_serious_error(exception_no_left_brace);
skip_or_parse_block(!parse_first);
// now GotByte = '}'
GetByte();
}
}
Input_ensure_EOS();
}
// Try to read a comma, skipping spaces before and after. Return TRUE if comma
// found, otherwise FALSE.
bool Input_accept_comma(void) {
SKIPSPACE();
if(GotByte != ',')
return(FALSE);
NEXTANDSKIPSPACE();
return(TRUE);
}
// Looping assembly ("!do"). Has to be re-entrant.
static enum eos_t PO_do(void) { // Now GotByte = illegal char
loopcond_t condition1,
condition2;
input_t loop_input,
*outer_input;
char* loop_body;
bool go_on;
int loop_start;// line number of loop pseudo opcode
// Read head condition to buffer
SKIPSPACE();
store_condition(&condition1, CHAR_SOB);
if(GotByte != CHAR_SOB)
Throw_serious_error(exception_no_left_brace);
// Remember line number of loop body,
// then read block and get copy
loop_start = Input_now->line_number;
loop_body = Input_skip_or_store_block(TRUE); // changes line number!
// now GotByte = '}'
NEXTANDSKIPSPACE();// Now GotByte = first non-blank char after block
// Read tail condition to buffer
store_condition(&condition2, CHAR_EOS);
// now GotByte = CHAR_EOS
// set up new input
loop_input = *Input_now;// copy current input structure into new
loop_input.source_is_ram = TRUE; // set new byte source
// remember old input
outer_input = Input_now;
// activate new input (not useable yet, as pointer and
// line number are not yet set up)
Input_now = &loop_input;
do {
// Check head condition
go_on = check_condition(&condition1);
if(go_on) {
parse_ram_block(loop_start, loop_body);
// Check tail condition
go_on = check_condition(&condition2);
}
} while(go_on);
// Free memory
free(condition1.body);
free(loop_body);
free(condition2.body);
// restore previous input:
Input_now = outer_input;
GotByte = CHAR_EOS; // CAUTION! Very ugly kluge.
// But by switching input, we lost the outer input's GotByte. We know
// it was CHAR_EOS. We could just call GetByte() to get real input, but
// then the main loop could choke on unexpected bytes. So we pretend
// that we got the outer input's GotByte value magically back.
return(AT_EOS_ANYWAY);
}
