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interpreter.cpp
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231 lines (215 loc) · 4.82 KB
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#include "interpreter.h"
#include "dumb.h"
void stmt(breezy_t *l, int &i){
breezy_t _var;
breezy_t _expr;
int label;
int j;
token_t stmt_type = l[i].token;
i++;
switch (stmt_type) {
case TOKEN_PRINT:
do {
if (l[i].token == TOKEN_STR){
Serial.print(STR_TABL[l[i].value]);
i++; // next token
} else if (l[i].token == TOKEN_COMMA){
Serial.print(" ");
i++;
} else if (l[i].token == TOKEN_ID){
_print(expr(l, i));
} else if (l[i].token == TOKEN_NUM || l[i].token == TOKEN_LPAREN){
_print(expr(l, i));
} else {
Serial.println(ERR": parse failed, you suck");
return;
}
} while (l[i].token != TOKEN_CR);
Serial.println();
break;
case TOKEN_IF:
breezy_t r;
r = relop(l, i);
if (l[i].token == TOKEN_THEN) i++;
else {
Serial.println(ERR": parse failed, you suck");
return; //error
}
if (r.value) stmt(l, i);
else {
do { i++; } while (l[i].token != TOKEN_CR);
if (l[i].token == TOKEN_CR) i++;
}
break;
case TOKEN_LET:
_var = l[i];
i++;
if (_var.token == TOKEN_ID && l[i].token == TOKEN_EQ){
Serial.println((char)('A'+l[1].value));
i++;
_expr = expr(l, i);
if (_expr.token == TOKEN_ERROR){
Serial.println(ERR": parse failed, you suck");
return;
} else
vars[_var.value] = _expr.value;
} else {
Serial.println(ERR": parse failed, you suck");
return;
}
break;
case TOKEN_CLEAR:
Serial.print(ESC"[2J"ESC"[0;0H");
break;
case TOKEN_LIST:
for (int i = 0; i < NVARS; i++) {
Serial.print((char)('A' + i));
Serial.print(" = ");
Serial.println(vars[i]);
}
break;
case TOKEN_END:
_loop = 0;
pc = 0;
Serial.println("OK");
break;
case TOKEN_GOTO:
if (l[i].token == TOKEN_NUM){
label = l[i].value;
for (j=0; j<MAX_LOOP_TOKENS; j++){
if (label == BREEZYXR[j].value && (j == 0 || BREEZYXR[j-1].token == TOKEN_CR) ){
// always go to first occurrence of the label
//j++;
while (j < pc){
j++;
Serial.print("PC = ");
Serial.println(j);
stmt(BREEZYXR, j);
}
return;
}
}
}
Serial.println(ERR": parse failed, you suck");
return;
case TOKEN_GOSUB:
case TOKEN_RUN:
case TOKEN_INPUT:
break;
}
}
breezy_t relop(breezy_t *l, int &i) {
breezy_t r1, r2;
token_t op;
r1 = expr(l, i);
op = l[i].token;
while (op == TOKEN_LT ||
op == TOKEN_GT ||
op == TOKEN_EQ ||
op == TOKEN_LE ||
op == TOKEN_GE ||
op == TOKEN_NEQ) {
i++;
r2 = expr(l, i);
switch (op) {
case TOKEN_LT:
r1.value = r1.value < r2.value;
break;
case TOKEN_GT:
r1.value = r1.value > r2.value;
break;
case TOKEN_EQ:
r1.value = r1.value == r2.value;
break;
case TOKEN_LE:
r1.value = r1.value <= r2.value;
break;
case TOKEN_GE:
r1.value = r1.value >= r2.value;
break;
case TOKEN_NEQ:
r1.value = r1.value != r2.value;
break;
}
op = l[i].token;
}
return r1;
}
breezy_t expr(breezy_t *l, int &i){
breezy_t t1, t2;
token_t op;
t1 = term(l, i); //all muls and divs
op = l[i].token;
while (op == TOKEN_ADD ||
op == TOKEN_SUB ||
op == TOKEN_AND ||
op == TOKEN_OR) {
i++;
t2 = term(l, i);
if (t1.token == TOKEN_ERROR || t2.token == TOKEN_ERROR)
return (breezy_t){TOKEN_ERROR, 0};
switch (op){
case TOKEN_ADD:
t1.value = t1.value + t2.value;
break;
case TOKEN_SUB:
t1.value = t1.value - t2.value;
break;
case TOKEN_AND:
t1.value = t1.value & t2.value;
break;
case TOKEN_OR:
t1.value = t1.value | t2.value;
break;
}
op = l[i].token;
}
return t1;
}
breezy_t term(breezy_t *l, int &i) {
breezy_t f1, f2;
token_t op;
f1 = factor(l, i); //vars, numbers
op = l[i].token;
while (op == TOKEN_MUL || op == TOKEN_DIV) {
i++;
f2 = factor(l, i);
if (f2.token == TOKEN_ERROR || f1.token == TOKEN_ERROR)
return (breezy_t){TOKEN_ERROR, 0};
switch (op){
case TOKEN_MUL:
f1.value = f1.value * f2.value;
break;
case TOKEN_DIV:
f1.value = f1.value / f2.value;
break;
}
op = l[i].token;
}
return f1;
}
breezy_t factor(breezy_t *l, int &i){
breezy_t r;
switch (l[i].token){
case TOKEN_NUM:
r = l[i];
i++;
break;
case TOKEN_ID:
r = (breezy_t){TOKEN_NUM, vars[l[i].value]};
i++;
break;
//Serial.println(ERR": not implemented");
//return (breezy_t){TOKEN_ERROR, 0};
case TOKEN_LPAREN:
i++;
r = expr(l, i);
if (l[i].token == TOKEN_RPAREN) i++;
else r = (breezy_t){TOKEN_ERROR, 0};
break;
default:
Serial.println(ERR": parse failed, you suck");
return (breezy_t){TOKEN_ERROR, 0};
}
return r;
}