printf( "%s", compile_mode == MODE_POSTFIX ? "/" : "\tPOP B\n\tPOP A\n\tDIV A, B\n\tPUSH A\n"); break; default: return;
void expr() { term(); while(1)
switch( lookahead )
case '+': match('+'); term();
printf( "%s", compile_mode == MODE_POSTFIX ? "+" : "\tPOP B\n\tPOP A\n\tADD A, B\n\tPUSH A\n"); break; case '-': match('-'); term();
printf( "%s", compile_mode == MODE_POSTFIX ? "-" : "\tPOP B\n\tPOP A\n\tSUB A, B\n\tPUSH A\n"); break; default: return;
int main ( int argc, char** argv ) { printf("Please enter an infix-notated expression with single digits:\n\n\t"); scanf("%20s", expression);
printf("\nCompiling to postfix-notated expression:\n\n\t"); compile_mode = MODE_POSTFIX; pos = 0; lookahead = *expression; expr();
printf("\n\nCompiling to assembly-notated machine code:\n\n"); compile_mode = MODE_ASSEMBLY; pos = 0; lookahead = *expression; expr();
return 0; }
Przykład możliwego wyjścia, wygenerowanego podczas wykonania powyższego programu:
Please enter an infix-notated expression with single digits:
3-4*2+2
Compiling to postfix-notated expression:
342*-2+
Compiling to assembly-notated machine code:
PUSH 3 PUSH 4 PUSH 2 POP B POP A MUL A, B PUSH A POP B POP A SUB A, B PUSH A PUSH 2 POP B POP A ADD A, B PUSH A