/* Interpret a single statement or block of code. When
interp_block() returns from its initial call, the final
brace (or a return) in main() has been encountered.
*/
void interp_block(void)
{
int value;
char block = 0;
do {
token_type = get_token();
/* If interpreting single statement, return on
first semicolon.
*/
/* see what kind of token is up */
if(token_type == IDENTIFIER) {
/* Not a keyword, so process expression. */
putback(); /* restore token to input stream for
further processing by eval_exp() */
eval_exp(&value); /* process the expression */
if(*token!=';') sntx_err(SEMI_EXPECTED);
}
else if(token_type==BLOCK) { /* if block delimiter */
if(*token == '{') /* is a block */
block = 1; /* interpreting block, not statement */
else return; /* is a }, so return */
}
else /* is keyword */
switch(tok) {
case CHAR:
case INT: /* declare local variables */
putback();
decl_local();
break;
case RETURN: /* return from function call */
func_ret();
return;
case IF: /* process an if statement */
exec_if();
break;
case ELSE: /* process an else statement */
find_eob(); /* find end of else block
and continue execution */
break;
case WHILE: /* process a while loop */
exec_while();
break;
case DO: /* process a do-while loop */
exec_do();
break;
case FOR: /* process a for loop */
exec_for();
break;
case END:
exit(0);
}
} while (tok != FINISHED && block);
}
void interp_block()
{
int value;
char block = 0;
do {
token_type = get_token();
if(token_type==IDENTIFIER) {
putback();
eval_exp(&value);
if(*token!=';') sntx_err(SEMI_EXPECTED);
}
else if(token_type==BLOCK) {
if(*token=='{')
block = 1;
else
return;
}
else switch(tok) {
case CHAR:
case INT:
putback();
decl_local();
break;
case RETURN:
func_ret();
return;
case IF:
exec_if();
break;
case ELSE:
find_eob();
break;
case WHILE:
exec_while();
break;
case DO:
exec_do();
break;
case FOR: exec_for();
break;
case END:
return;
}
} while (tok != FINISHED && block);
}
